Tag Archives: crawl space

Post Frame Footings, Delivery Limitations, and Foundation Types

This Wednesday the Pole Barn Guru addresses reader questions about common gable post frame footings, weight limitations for a building delivery and the possible solutions, and what types of foundations Hansen Buildings can design for in Weld County Colorado.

DEAR POLE BARN GURU: What is a common gable post footing compared to a main truss post footing, where are these located on a building? ELLIOT in PINEHURST

DEAR ELLIOT: Most post frame buildings are rectangular, with peaks (a point or gable) on opposite ends. Building codes require a minimum footing thickness of six inches, or an ICC-ESR approved alternative (like these https://www.hansenpolebuildings.com/2014/05/footingpad/). Main truss post footings will be located along the eave (side snow slides off of) and support roof trusses (hence ‘main truss post’). As they carry more weight than endwall (peak of roof ends) columns, they will typically be larger in diameter. Your building’s engineer sealed plans will specify locations and diameters required to adequately support weight of building (including applied loads). This is not a place to guess or scrimp, as you really wouldn’t be happy with any of your columns settling.

 

DEAR POLE BARN GURU: 50x 50 x 16 pole barn approximate weight, limited by bridge on property? NEIL in TULSA

DEAR NEIL: A far greater issue than weight of your building package (roughly 20,000 pounds total depending upon features) will be weight of trucks making deliveries (many weigh 32-40,000 pounds when empty). We have had many clients in a similar situation to yours and materials can often be offloaded onto a flat trailer you can pull behind a pickup, or similar, in order to get into challenging jobsites. Biggest concern will be 50 foot long roof trusses, as truss truck is going to be a semi pulling usually a 48 foot long trailer. You might want to consider making a donation to your local high school’s football team in order to have them physically pick up and carry individual trusses across bridge and to your site.

 

DEAR POLE BARN GURU: What type of foundations are used in Weld County, CO for pole barn homes? Insulated slab on grade? Crawl space? BRENT in KERSEY

DEAR BRENT: We have provided roughly 300 fully engineered post frame buildings to our clients in Colorado (many of these in Weld County). Types of foundations for post frame homes are nearly as varied as are our clients. We’ve done full or partial basements (including walkout or daylight) in block, poured concrete or ICF; crawl spaces (both conditioned and non-conditioned) as well as slabs on grade (both with heated slabs and under floor insulation or unheated slabs with perimeter insulation). Embedded columns are going to be least expensive and strongest, however we can also design and provide for cases with ICC-ESR approved wet set brackets. With most sites in Colorado, it is beneficial to involve a Geotechnical engineer to do a proper assessment of your site’s soil conditions and bearing capacity in order to assure best outcome. Often jurisdictions will make this a requirement. Here is some extended reading on slabs vs. crawl spaces: https://www.hansenpolebuildings.com/2019/03/slab-on-grade-or-crawl-space/

Foundation Requirements, Stem Walls, and Building on Slab

This week the Pole Barn Guru answers reader questions about the type of foundation and uplift requirements there is for and RV cover and “what not,” building a home on a stem wall or with crawl space, and pluming for a building built on slab.

DEAR POLE BARN GURU: For a 24 x40 x12 pole barn residential use as an RV cover and what not what type of foundation and uplift requirements are there other than the post being set around 4 feet in the ground? STEVE in FORT MCCOY

DEAR STEVE: Column embedments and encasements need to be engineered to adequately resist uplift, overturning and gravity and will be determined based upon design wind speed and wind exposure, roof dead loads (plus snow in more northern climates), whether building is enclosed, open or partially enclosed, etc., as well as soil bearing capacity. When columns are effectively constrained by a concrete slab on grade, it helps to potentially reduce depth, diameter and required amount of concrete needed for hole. Due to complexity of these factors, embedment and encasement, as well as any added uplift plates or cleats should only be determined by whatever engineer will be sealing your plans. He or she should also provide verifying sealed calculations to certify adequacy. A consideration – if this will be a roof only structure, Moment (bending) loads on columns are four times as great than on a fully enclosed structure – this results in more concrete being needed for holes.

 

DEAR POLE BARN GURU: I’m building a post frame building/house. I want to use stem wall or pillars, wet set brackets. Is there a huge cost difference or benefit over the other? Does stem wall, if used, have to be on a footer or does it act as it’s own footer? I want floor to be 1.5′ above grade if that makes a difference. Thank you for your time and input. LONZY in CONWAY

DEAR LONZY: Post frame buildings make for excellent homes! Great choice. My educated guess is your floor is going to be over a crawl space. If so, your top of floor will probably end up being more like two feet above grade, rather than 18 inches. This allows for better access to utilities as well as not requiring all supporting beams and joists to be pressure preservative treated. Concrete stem walls will need to be at least six inches thick and on top of a six inch deep by 12 inch wide concrete footing (for a single story), resulting in a far greater investment in forming and pour (both in materials and labor). Concrete piers are pretty low tech and then sides of your crawl space will consist of (usually) steel siding.

 

DEAR POLE BARN GURU: What is the best way to plumb a pole barn home. I would like to keep the concrete floors, but I need a way to plumb it without having to jackhammer concrete when there is an issue. NICHOLAS in LOUISVILLE

DEAR NICHOLAS: In all reality, chances of a modern plumbing failure under a concrete slab are very, very small. Tens of thousands of homes and apartments are built every year in our country with plumbing under concrete floors, attesting to how rare a failure occurs. Older slab on grade buildings have had challenges from deterioration or perforation of copper pipes or joint issues. Your best prevention is a well-prepared site, as shifting soils are your most likely cause of a plumbing challenge. Remove any expansive soils and compact fill in no greater than six inch lifts. Keep water from being able to run under your home – by grading away from building perimeter at least 10 feet at a 5% slope. Build pad for building up above surrounding property. Use French drains if underground water is suspected. Drain gutters sufficiently away from home. Use PEX for all under slab water lines. All pipes need to be extensively tested for drainage and air pressure in supply lines multiple times during rough-in process prior to slab being poured. Testing should take place once after rough-in is completed and before backfill when dirt is pushed back into trenches to cover pipes. It should be tested once again after backfill has taken place to ensure no damage to pipes, then once again after concrete slab prep has been finished. I have heard of people running their under slab PEX through larger diameter sleeves, however this seems to be an unnecessary expense.

Post Frame Design Questions

Regarding Post-Frame Home Design
Reader MAUREEN writes:
“Hello. I was forwarded to you because I have some questions for you regarding my home
design.
What are the most economical size of trusses?
What brand of doors and windows do you use?
Can Hansen Buildings be built on a crawl space foundation?
Can in floor heat be used in crawl space foundations?
Are foundation designs sent for the foundation prep company?… to ensure the correct
foundation?
And please send your financing options.
Thank you!”

Mike the Pole Barn Guru says: 

Planning your new home around what span of trusses might be most economical is likely to end you up with a less than desirable outcome as you are trying to fit your ideal spaces into a preordained box, rather than creating a box to best fit your spaces. With identical features, building shells (other than in extreme wind or snow situations) become less per square foot up
to 40-50 foot spans, then generally level off until clearspans exceed 80 feet.

Here are some thoughts you may find helpful:
Have professional floor plans and elevation drawings done before pestering a builder. Very
few builders are professional designers or architects – expecting them to be is unrealistic.
If you do not own the dirt, it is impossible to craft a barndominium plan to best fit with your
building site.

Some plan tips to consider:
Direction of access – driveways are not cheap and shortest distance between two points is a
straight line.
Curb appeal – what will people see when they drive up? This may not be important to you,
however someday someone will try to resell your barndominium.

Is there an appealing view?
North-south alignment – place no or few windows on north walls, but lots of windows on south
wall (in the South reverse this). Roof overhangs on south wall should provide shade to windows
from mid-day summer sun.

Is there a slope on your building site?
Work from inside out – do not try to fit your wants and needs within a pre-ordained box just
because someone said using a “standard” size might be cheaper. Differences in dimensions
from “standard” are pennies per square foot, not dollars.

Popular home spaces and sizes need to be
determined:  https://www.hansenpolebuildings.com/2019/09/room-in-a-
barndominium/ and https://www.hansenpolebuildings.com/2019/09/the-first-tool-to-construct-
your-own-barndominium/.

With all of this in mind, order your custom designed floor plans
here: http://www.hansenpolebuildings.com/post-frame-floor-plans/

We furnish Plyco insulated commercial steel entry doors, with steel jambs. Both doors and
jambs are factory finish painted. These doors are available in six panel and cross buck styles,
with a variety of glass options.

Our windows are dual glazed vinyl and can be ordered with tempered glass. They come from a
variety of manufacturers and have appropriate U-factor and SHGC rating for your particular
climactic conditions.
More window and door information can be found within our Product Guide
https://www.hansenpolebuildings.com/pdfs/Hansen-Buildings-Product-Guide.pdf

Yes, our fully engineered buildings can be erected with crawl spaces (and do not necessarily
require perimeter concrete foundation walls)
https://www.hansenpolebuildings.com/2019/03/slab-on-grade-or-crawl-space/

Radiant floor heat can be incorporated into post frame crawl space designs.
Most of our clients use embedded columns for their foundation. Regardless of whether you go
this route, use piers with wet-set brackets, thickened edge slab with wet-set brackets, poured,
ICF, or CMU foundations, our engineered plans will include foundation designs.

Here is information of our financing: www.HansenPoleBuildings.com/financing
This book (co-authored by me) may also prove helpful https://www.amazon.com/Pro-Tips-Your-post-Frame-Home-

Saving a Poorly Designed Crawl Space

Saving a Poorly Designed a Crawl Space

Reader GEORGE in VIENNA writes:

“I am substantially replacing rotted parts of an existing building set on short 6×6 treated posts which are in good condition. above the posts it is conventional platform construction, and untreated. Unfortunately, the original builder set the building partially into the side of a hill in an attempt to use thermal mass and reduce energy use in its off-grid location. The uphill side was backfilled to a height of approximately 30″ above the interior floor, which is OSB over untreated 2×12 beams and untreated 2×6 joists. Skirting to keep out moisture was untreated plywood, poly sheet, and Styrofoam block insulation. In 6 years, there is substantial rot of the perimeter plywood, perimeter 2×12 rim joists, some 2×6 floor joists, some areas of the OSB flooring, the untreated sole plate and a few studs above. Otherwise the building walls, windows, doors, roof trusses, metal roof, insulation, etc., are well made and in good condition. We are temporarily supporting the building from below and removing the failed materials all the way around. We are removing the backfilled dirt on three sides to expose the posts and provide airflow underneath. All rim joists, beams, and floor joists will be replaced with treated materials. I am looking for advice in two areas (1) floor insulation, either under or over the OSB, and (2) treated skirting around the perimeter which would allow partial backfill and maintain ventilation.” 


Mike the Pole Barn Guru says:

You really have two options:

You could condition your crawl space – this would require a 6mil or thicker, well-sealed vapor barrier to cover underlying soil and up perimeter walls to floor joists. There would be no vents with this method, however an air-circulating device must be provided. Perimeter walls should be insulated using either closed cell spray foam or rock wool batts. 

From Building Code Section 308.3, Unventilated Crawl Spaces

The air-circulating device must move at least 1 cubic foot of air per 50 square feet of crawl space area. The crawl space floor area must be completely sealed with a vapor-retarding material. The edges of the vapor retarder must be lapped up against the inner foundation walls.

Read more about encapsulated crawl spaces here: https://www.hansenpolebuildings.com/2020/11/11-reasons-why-barndominium-crawl-space-encapsulation-is-important/
Or – have an unconditioned crawl space, where your vapor barrier would cover the ground surface. Insulation would ideally be beneath OSB – between floor joists. Again, same choices for insulation – just between joists. With this choice foundation vents would need to be added to perimeter walls.

Most building codes require 1 square foot of open ventilation area for every 150 square feet of crawlspace. Generally, Automatic Foundation Vents have 50 inches of net free area per vent. Therefore, install one vent for every 50 square feet of crawlspace.

FDN (Foundation) rated pressure preservative treated plywood will probably be your best skirting material.

Rubble Trench Foundations

Rubble Trench Foundations for Post Frame Homes?

My social media friend and loyal reader TRENT in NAMPA writes:

“Hi Mike, Ii would like your thoughts on some foundation ideas I have for post frame homes. The main purpose I am trying to achieve is to have perimeter concrete at the base of the building while reducing the cost of a standard stem wall foundation. This would allow you to insulate slab edge at the interior side, giving the building the look of having a more standard foundation. The option of making a raised floor crawl space, think of an old craftsman home when they did not excavate crawl spaces down below grade. Not sure if this all makes sense or not. Idea#1 bore typical 48+ inch depth holes for column footings. Dig a perimeter trench for a rubble trench foundation footing, pour a concrete grade beam with rebar and fill column footings at the same time. Use wet set brackets or bolt down style. Idea #2: dig a rubble trench foundation footing, pour a concrete grade beam with enough size/width to take the load off columns, mount columns to grade beam with metal brackets.”

Mike the Pole Barn Guru says:

Other than for looks, I am unsure of why one would want to go through efforts of having a concrete perimeter. I am not seeing why your suggestions would not work (other than bolt down brackets as they do not resist moment loads), just not maybe a most economical design solution.

We have provided numerous post frame homes over crawl spaces. Almost universally, no excavation has been done other than to level the site. With a raised wood floor, you can either leave crawl space unconditioned and insulate between floor joists, or condition space and insulate the perimeter wall below floor.

For slab on grade applications, a two foot deep trench can be dug around the perimeter, bore the balance of hole in the bottom of the trench (in our case, usually our total hole depth is 40″ with a 16-18″ deep concrete bottom collar). After columns are placed and splash planks are installed, R-10 EPS insulation can be attached to the inside of splash planks (not required in Climate Zones 2 or less), with top of insulation at top of slab, then down vertically two feet. At the base of vertical insulation (in Climate Zones 4 and greater), use the same insulation to go out horizontally two feet. Backfill trench with compactable material and call it a day. If concrete piers and wet set brackets are desired, square forms can be fabricated out of R-10 EPS to insulate piers.

Spray Foam, Crawl Space Floors, and Column Sizes for Shed

This week the Pole Barn Guru answers reader questions about spray foam application of a vapor barrier, finishing a crawl space floor, and to go with 3 ply or 4 ply columns– this is dependent upon many things.

DEAR POLE BARN GURU: New Construction – Can spray foam insulation be spray over a vapor barrier blanket in the roof of a pole barn, too increase insulation rating?

Thank you, TERRY in WILSONVILLE

DEAR TERRY: In your part of our world, most often roof condensation is controlled by use of what is known as a “Condensation Control Blanket” – a thin layer of fiberglass bonded to a white vinyl backing. When laps are properly sealed (rarely done right) it does make for an effective vapor barrier, although it provides minimal, at best, insulating value.

I am not a fan of spray foaming to any flexible barrier in walls or roofs (https://www.hansenpolebuildings.com/2020/04/spray-foam-insulation-3/).

My first choice would be to design your building to be capable of supporting a ceiling, use raised heel trusses and blow in fiberglass insulation. With raised heel trusses you can get full thickness from wall-to-wall and you do not end up heating dead space between roof trusses. Roof steel should be ordered with a Integral Condensation Control (https://www.hansenpolebuildings.com/2020/09/integral-condensation-control-2/) and adequate ventilation provided at eaves and ridge.

Second choice would be to omit condensation blanket and Integral Condensation Control and use two inches or more of closed cell spray foam directly to underside of roof steel. This will not be nearly as effective as choice number one.

 

DEAR POLE BARN GURU: After reading several articles on your website I’m leaning towards building a single story post frame home with about a 4 foot crawl space so that I get benefits of a floor not hard on the joints and access to any plumbing or electrical if things go wrong. I would also like to build as close to a passive or net zero home (within a reasonable budget) but was wondering how to do that with a dirt floor crawl space. I’ve read that the best way is to keep crawl space within the envelope of the home but I’ve only read of a vapor barrier that is covering the dirt floor. Thanks for all your help. TODD in HENNING

DEAR TODD: Thank you for being a loyal reader. My knees and your joints must be related – as nothing pains me more than standing on a concrete floor for even relatively short periods of time.

Most crawl spaces are created with dirt floors, face it, they are low budget and meet Code with a 6mil black Visqueen Vapor Barrier installed. Now retired Hansen Pole Buildings’ Designer Rick Carr built himself a hunting cabin over a crawl space a year ago and decided to take a slightly different route. He opted to do a thin layer of concrete to cover ground in his crawl space, with an idea of being able to roll around using a mechanic’s creeper, should he need to work on sub-floor utilities. Here is an excerpt from part of Rick’s planning: https://www.hansenpolebuildings.com/2019/03/pole-barn-cabin-part-ii/

 

DEAR POLE BARN GURU: I am putting up a 60x135machine shed. 18 ft sidewalls, I’m wondering if the 3 2×8 laminated columns are enough or if i should spend 2900.00 more to go to 4 2×8 columns. thanks, SHANE in ASHTON

DEAR SHANE: Your question leads me to believe you are attempting to make a hundred thousand dollar plus building investment, without benefit of fully engineered structural plans.

Column sizes will be dictated by effects of column spacing, design wind speed and exposure (an Exposure C site being subjected to 20% greater wind forces), roof snow loads, dead weight of roof system (including any ceiling), roof slope as well as proper diaphragm design of your building shell.

I will implore you to please, please, please build only from a fully engineered plan. Think of it as an investment into one-time insurance. I only want to see you put this building up one time.

A Crawl Space, Building Size Options, and An Addition

This Monday the Pole Barn Guru discusses building a post frame building over a crawl space, whether one should build up or out, and if it is possible to build on to an existing building with a post frame structure.

DEAR POLE BARN GURU: When building a post frame on a crawl space with post spaced every 8-10 feet, how does one support the floor joists around the perimeter? Thanks. JERRY in LEWISPORT

DEAR JERRY: In most instances floor joists will be supported by beams attached to wall columns. If you are looking at a design with zero barrier (think wheel chair accessibility) then you can excavate down and we can engineer a permanent wood foundation between columns. This allows for floor joists to be supported by short pressure preservative treated wood foundation walls and reduces your building’s profile. https://www.hansenpolebuildings.com/2020/10/post-frame-home-zero-barrier-entry-over-a-crawl-space/

 

DEAR POLE BARN GURU: My wife got a quote for a 40x60x16 and it’s a little much for what we want. Is it possible to to do a 40x40x 15 or 16 with enough ceiling load for a 2 story living quarter that will be in half of it? Our building code is IRC 2018 and we have a minimum snow load of 50# and wind load of 90mph. JAKE in RATHDRUM

About Hansen BuildingsDEAR JAKE: My first encouragement would be, if at all possible, to build as big as you think you will need – as no one has ever come back to me and said what they built was just too big. Even if you have to borrow some in order to do so – with today’s low interest rates it is likely to be manageable. In order to get two stories, at least your living area will need to have a taller eave height https://www.hansenpolebuildings.com/2020/05/how-tall-should-my-eave-height-be-for-two-stories/ regardless of footprint dimensions. Your Hansen Pole Buildings’ Designer will be reaching out to you to discuss further.

 

DEAR POLE BARN GURU: Can I use pole barn construction to add to an existing residential structure? I.E. room addition. DAVID in MOORESVILLE

DEAR DAVID: You can absolutely use fully engineered post frame (pole barn) construction to add onto your house. Roofing and siding can be planned to match your existing construction as well – making everything tie together seamlessly.

 

 

 

Doesn’t Like Idea of Concrete Slab on Grade Foundation

Doesn’t Like Idea of a Concrete Slab Foundation

Loyal reader ASHLEY in KELSO writes:

“I will be building in southwest Washington – Cowlitz County. We are wanting around a 2800 square foot home. I do not like the idea of a concrete slab “foundation”, we are going with crawl space (I read your blog on that =) ) I have just a few questions. Do you offer your services in Cowlitz County? What permit codes should I be looking for when contracting out/doing it ourselves to make this into a home? Not only is this our first build, it will be done by us so Will contracting out be more expensive for a pole barn home since it’s not a typical stick built? Or is the work roughly the same? Hope this all makes sense. Thank you so much.”

Well Ashley makes total sense.

Hansen Pole Buildings actually provides more buildings in Washington State than anywhere else in the country! In Cowlitz County alone, I would not be surprised if you couldn’t find well over a hundred of our buildings.

You will find crawl spaces to be a very effective alternative to slab on grade using fully engineered post frame construction and we see more and more people interested in this as a design solution. Personally, my knees would scream at me if I had to stand on concrete for more than perhaps 15-20 minutes.

Self-contracting will save you a good chunk of change (often 25% or more) and if you are reasonably physically capable and will read our step-by-step assembly instructions you can successfully erect your own beautiful building shell yourself. You will find a post frame building shell goes together quicker than stick built, because there are frankly fewer pieces to handle!

Any subcontractors for electrical, plumbing, HVAC should be roughly similar in price whether stick or post frame – your savings comes from being your own general contractor, DIYing as much as possible and a huge reduction in foundation investment.

Here is your Planning and Building Department ‘homework’ to get you started:

https://www.hansenpolebuildings.com/2020/01/your-barndominiums-planning-department/


https://www.hansenpolebuildings.com/2020/08/building-department-checklist-part-i/

What Hansen Pole Buildings Offers for Prospective Barndominium Owners

What Hansen Pole Buildings Offers for Prospective Barndominium Owners

If you are considering building a barndominium or shouse (shop/house), whether DIY or with a contractor’s involvement, there is one very important question to ask:

“Do you personally live in a barndominium?”

If you do not receive a resounding, “YES” for an answer, you may want to rethink your choice.

My lovely bride and I have lived in our Hansen Pole Building along South Dakota’s Lake Traverse for 15 years now. This being my third personal barndominium, dating back some thirty years, I can speak with experience few others can.

Hansen VisionAt Hansen Pole Buildings, we are literally “All About the Building” and we strive to provide “The Ultimate Post Frame Building Experience™”. Every single one of our fully engineered post frame buildings is custom designed to best fit our client’s wants and needs. Rarely will we be least expensive, however we will always provide a best value solution.



This process ideally begins in infancy stages, with a determination of fiscal reality – highly tempered by individual tastes and how much effort one is willing or able to put into their new home. Those willing to be their own General Contractors can plan upon saving roughly 25% over hiring a builder to turn key and 50% for DIYing as much as possible. We have found any physically capable person, who is willing to read step-by-step directions in English can successfully erect their own beautiful building, and many do. We have even had septuagenarian couples do their own construction!

Most often a DIY barndominium turns out with better results than one could ever hire done – because you truly care about how it turns out.

Once a budget has been established, it is time to ‘find the dirt’. Without knowing where your barndominium will be located, it is impossible and impractical to determine how your new home should be planned. Important aspects such as direction of access, curb appeal and views play into a well thought out design.  Directional orientation is important, with heat loss or gain determined by location and number of windows, as well as design of shading from overhangs. Slope of site determines needs for significant grade work or placing upon a full or partial basement or crawl space.

Moving closer to actuality we provide direction and encouragement in determining your family’s needed spaces, sizes and orientation to each other. Work from your home’s inside rather than trying to fit what your needs are into some pre-ordained space. With this information in hand, we offer a potentially free, professional floor plan and building elevation service to take all of your ideas, wants and needs and actually craft a floor plan best melding them with realities of construction.

Whether you have utilized our plan service, or have a plan of your own, your Hansen Pole Buildings’ Designer will work directly with you to make recommendations to provide a home most practical for you. You have total choice over a virtually unlimited number of aspects. Your being directly involved eliminates builders taking advantage of you in order to pad their bottom line. Hansen Pole Buildings does have a unique Instant Pricing™ system, allowing your Building Designer to make changes and have a near instantaneous answer as to what your investment will be as various dimensional and feature changes are contemplated.

We are very conscious about design for energy efficiency. Power is unlikely to ever become less expensive, so getting at or as close as possible to a net zero design is paramount.

Need financing for your new barndominium? We work with several lenders who actually understand post frame barndominiums and can assist with this phase.

After your building order has been placed, it moves from your Building Designer’s desk to our design team. Before going to one of our skilled draftspeople every building comes across my desk for personal review – mostly in an aspect of what will or will not work structurally, Building Code compliance and how to increase building efficiency without compromising functionality.

Once your structural building plans are completed, you get to review them for accuracy prior to our independent Registered Professional Engineer going over every member and connection as a final assurance of structural soundness. Only after all of these steps have been completed are your engineer sealed plans, along with verifying structural calculations, sent to you to acquire necessary building permits.

Even if your jurisdiction does not require building permits, structural plan reviews or do inspections, having engineer sealed plans is your assurance of structural adequacy. There are insurance companies who give discounts to those who build fully engineered homes, so ask your agent for yours.

You have access through our online portal to follow your building’s process, reschedule build dates, report any damaged or missing materials, as well as requesting unlimited technical support from those who have actually built post frame buildings.

Even after your barndominum is complete and you have sent us digital photos of your beautiful new home, our commitment to you does not end. Hansen Pole Buildings provides a Limited Lifetime Structural warranty covering your home and regardless of how many years you have had your building, should you have questions or concerns, we are available to assist.

Avoid Being Driven Crazy With Barndominium Questions Part I

Avoiding Being Driven Crazy With Barndominium Questions Part I

Loyal reader and client GREG in KENTWOOD is planning his new post frame barndominium home and has questions no one else will answer. Mike’s answers are in italics.

Mike,

Good morning, I hope all is well with you.  

 I have some questions that I would like to understand and it is driving me crazy, because no one other than Hansen Pole Building, it seems will answer my questions and return my calls.  Most the crazy part is about the slab. I find cement workers are not great communicators.  I am 56, a mechanical engineer, have renovated several houses from the studs up, I can do plumbing without butt crack showing, I raced stock cars for 10 years, I tell you this, because I know how to build stuff and am not afraid of hard work. My job requires a detailed list of Bill of Materials, precision drills and reamers and very detailed processes to make fuel injection parts, ABS brake parts and other.  I hope you can help out, as I am ignorant about some simple facts that are driving me crazy.

Mike: We believe good communication is essential to successful completion of most any building. You will find we strive towards written communications in order to minimize (or eliminate) possible miscommunication of important facts and details).

I also would like to say Brenner is doing a fine job.

Mike: Brenner has a passion for post frame buildings and he is not at all afraid to reach out to higher authorities for answers to complex structural questions.

Due to your great level of communication, you so far are my #1 choice to partner with on my new house.  I also would be willing to visit you in MN if you have/think I could see examples of my questions first hand.  

Statements from details I learned at Code Meeting:

  • In Michigan, in my county I need to have a 2’ foam, below grade, with R10 barrier, around the full foundation or slab perimeter. 
  • So my building code staff recommends a Rat Wall 2’ below grade, or a crawl space with footers, or a slab with a wooden wall built to hold the 2’ foam below grade.
  • I don’t really have a problem with the Rat Wall, but it certainly will add more cost to cement.

My questions on this topic are:

    • If using a Rat Wall, it seems like the 6” * 6” poles will then be encapsulated in cement for about 2.5’ at minimum.  I thought the poles were not supposed to be in cement as it causes probably more decay than dirt.
      Mike: Concrete does not cause premature decay of properly pressure
      preservative treated columns.
    • What are your thoughts?
      Mike:
      Personally I would build over a crawl space because my knees are far happier living on wood than concrete.
    • What would you recommend for the 2’ below grade issue regarding the slab foundation?  Mike: With a slab on grade, you can use rigid perimeter insulation without a need for a ‘rat wall’ or wood foundation wall. It can be held in place by backfill on each side. It can be placed running from below base trim on exterior of splash plank, or on inside of splash plank. If on inside of splash plank, it eliminates having to protect it from possible UV degradation.

On attachment pictures in the middle pages show where the 6” X 6” poles go and spacing, listed are my questions:

I am concerned with spacing of 12’ and 14’ of the 6” X 6” posts.  (I’m sure the loading is OK, within code, but see below)
Mike:
Actually with your 21 foot eave height and Exposure C for wind 6×6 columns will not engineer out. Your building will have glulaminated columns manufactured out of high strength 2×6 or 2×8 depending upon location.

    • One concern is getting wood in today’s supply chain that are straight enough for the girt boards and purlins at 12’ and 14’, should I be concerned? ( I can’t get straight 2” X 4” at 8’ for the walls I have built in last year alone.) Mike: Lumber is obviously organic and we can no longer cut down those old growth trees where one might be able to get straight grained, narrow growth ringed lumber with few or no defects and very little warp, twist or cup. One beauty of steel roofing and siding is it hides a plethora of framing imperfections (like warp), due to high ribs of steel siding.

When using double trusses, at all locations, why not just go to 8’ centers on the poles?   I know it is more 6” X 6” poles, but really is not anymore trusses and may help get straighter girt and purlin boards. 
Mike: Wider spaced columns allow for more flexibility in location of doors and windows and an added advantage of not having to dig as many holes. If you were thinking of using a single truss every eight feet, rather than a double truss every 12, I would discourage it. Double trusses allow for true load sharing and eliminate any possibility of a single truss having a weak point, where under extreme loads (beyond design loads) it may fail and bring down your entire roof.

Come back tomorrow for Part II in Barndominium Questions!

Post Frame Home Zero Barrier Entry Over a Crawl Space

Post Frame Home Zero Barrier Entry Over a Crawl Space

Reader MARC in AUBURN writes:

“I am asking what might be an odd question, but I need to ask it to see if it is even an option.

Is it possible to build a post frame home with part of it having a concrete floor (garage area) and the other part be built on a raised wood joist subfloor spring that I have a 4 foot crawl. The trick is, I want zero barrier entry so the sub floor and the garage floor would need to be level. Same with porches, etc.  is this doable without building an actual foundation wall around the home section?  I want to avoid traditional foundations and want to rely on the superior properties of a properly engineered and constructed post frame building. Am I better off just going all slab without a crawl?  

Thank you!”

Not an odd question at all and yes it is an option. I (and my knees) personally prefer to live on wood floors, rather than concrete. Our household also relates to zero barrier entry as my lovely bride Judy is a paraplegic confined to a wheelchair.

We can design your living space using permanent wood foundation walls between roof supporting pressure preservative treated columns.

Treated wood foundations are load-bearing, pressure-treated wood framed walls, used below grade to support light frame construction. Treated wood foundations are commonly called Permanent Wood Foundations or All-Weather Wood Foundations. Since being developed in the 1960s, this unique building system has proven to be a durable building system in thousands of physical applications. Treated wood foundations have undergone extensive research, analysis, and testing by several highly respected building construction industry organizations. They have been approved for use by model building codes, federal agencies, and by lending, warranty and insurance institutions. A treated wood foundation, when installed, waterproofed, and drained properly, and used in conjunction with other waterproof materials, is a viable alternative to poured concrete or concrete block foundations. When I added onto my home near Spokane, Washington 30 years ago, I utilized pressure preservative treated wood as a foundation around an irregular crawl space supporting two floors and cantilevered decks above. It has performed admirably, even in a severe lakefront environment.

Treated wood foundations are built on most types of soils (Group I – III), with an exception of unsatisfactory soils (Group IV) as defined by the U.S. Department of Agriculture. Group IV soils typically have over 40% clay, less than 50% sand and may have a high shrink-swell potential. Similar to conventional foundation systems, sites should be cleared of organic material and top soil prior to work onset. Crawl space is then excavated, and a footing is placed on undisturbed soil below frost line. Footings under a treated wood foundation wall can be made of poured concrete or a wood footing plate on top of granular fill. In my case, I used a poured concrete footing, however in your instance, since vertically carried loads would be minimal, gravel should prove more than sufficient. as footing size is engineered based on foundation wall loads. Adequate, unobstructed drainage around a treated wood foundation is achieved by having continuous granular fill on building sides and underneath structure. Granular material can be up to 1/2 inch crushed stone, 3/4 inch gravel or 1/16 inch sand depending on where it is intended to be used. All granular material should be clean and free of silt, clay and organic material, and be covered with a 6-mil polyethylene sheeting. Sump pumps, perimeter drains, and dry wells may be used under your crawl space floor and around the exterior to promote drainage.  Storm water control including gutters, downspouts, splash blocks and drainpipes, in addition to a properly sloped finish grade, is also important to direct water away from the structure. 

Materials used to construct treated wood foundations include: plywood, preservative treated lumber, fasteners, termite protection (where appropriate), a moisture barrier, sealing, and insulation. All framing lumber below grade in a treated wood foundation is required to be pressure treated with preservatives in accordance with the American Wood Preservers’ Association (AWPA) Standard C22, “Lumber and Plywood for Permanent Wood Foundations – Preservative Treatment by Pressure Processes.” An important consideration when building a treated wood foundation is the metal used in the fasteners. Due to the high levels of copper in wood preservatives, fasteners are required to be a corrosion-resistant. Type 304 or 316 stainless steel nails are recommended.

An essential part of a treated wood foundation system is moisture and termite protection. In addition to a 6-mil polyethylene sheet wrapped around exterior plywood sheathing, all sheathing joints must be caulked with a high-performance acrylic latex or polyurethane caulk. Preservative treated wood eliminates termites from crawl space framing, because termites cannot penetrate it; however, additional steps should be taken to protect untreated floors above.

Several advantages make treated wood foundations an attractive option. Construction of a treated wood foundation is simple to erect, in comparison to concrete foundations. Treated wood foundations also offer advantages over concrete foundations such as an ability to install insulation between studs, affording a higher R-Value in comparison to uninsulated concrete foundation walls, leading to greater energy efficiency.

A Dog Trot Post Frame Home

A Dog Trot Post Frame Home

Welcome back!

If you missed yesterday’s installment, you will want to flip a page back, otherwise this will not make sense!

Thank you Jim for your kind words – so much to write about and so little time 🙂 I do endeavor to provide to anyone who wants to read, best possible and researched information. I also tell it like it is, rather than just giving answers you want to hear.

For those who may read this later, a ‘dog trot’ style building historically has two individual sections, connected by a breezeway. Dog trot homes are typically raised off the ground and have a wide front porch along an entire length. Normally one section will have ‘day functions’ (cooking, dining, living) and its counterpart will have ‘night functions’ (sleeping, bathrooms). I would encourage you to consider putting up this building shell in its entirety at one time as there will be economies to be derived in only one set of deliveries as well as labor savings in not having to tear anything apart in order to conjoin first and second stages. You could certainly complete all inside finishes of each section independently.

Being able to pass a blower test is less a function of the structural system than it is of properly constructing a well-sealed building envelope. It is also not yet a nationwide mandate – Florida just happens to be one of a handful of states where it is required. By using two inches of closed cell spray foam insulation on all surfaces and properly installing all doors and windows you should have no issues with passing a blower test. Our third-party engineers do a thorough check on every member and connection to ensure all are adequately designed to resist the imposed loads – including column uplift. Screw tie downs will not be required in order to resist columns uplifting (at least not by our engineers). Raised wood floors (over crawl spaces) are becoming more and more popular as people are realizing they are available and do not like the idea of living upon concrete floors https://www.hansenpolebuildings.com/2019/03/slab-on-grade-or-crawl-space/ . One of our recently retired Building Designers, Rick Carr, has recently built a hunting cabin for himself over a crawl space https://www.hansenpolebuildings.com/2020/06/fishing-cabin-insulation/.

One of our Building Designers will be reaching out to you for further discussions. I would also recommend you get into our queue for getting floor plans and elevation drawings generated http://www.hansenpolebuildings.com/post-frame-floor-plans/?fbclid=IwAR2ta5IFSxrltv5eAyBVmg-JUsoPfy9hbWtP86svOTPfG1q5pGmfhA7yd5Q.

Slab or Crawl, Insulation, and Building by a Leach Field

This Monday the Pole Barn Guru answers reader questions about building on a slab or with a crawl space, insulation for a shop, and if a person is able to build near a leach field.

DEAR POLE BARN GURU: I appreciate the building technology used when building a residential pole barn. I am not yet convinced about a slab floor. Although radiant heat is a plus I have two concerns. 1st I’m not sure of the impact when walking on concrete and what is done about air conditioning the building. Have you seen pole framing on a stem wall crawl space deck. Thanks. JOHN in SUMMERSVILLE

DEAR JOHN: Although our own shouse has geothermal radiant floor heating and cooling (https://www.hansenpolebuildings.com/2016/12/modern-post-frame-buildings-geothermal/) I tend to agree with you about what surface I would like to live upon. If I had to stand on concrete for very long, my knees would be screaming at me. We have provided many post frame buildings built over crawl spaces, with most using embedded columns and attaching raised wood floor supports to them. This is far more cost effective than pouring a stemwall (we have had clients go this route as well). For extended reading please see https://www.hansenpolebuildings.com/2019/03/slab-on-grade-or-crawl-space/.

DEAR POLE BARN GURU: I’m working with Greg Lovell on a building design. Pole barn 30 x 48 x 10 will be walled of to two 24 X 30 shop areas.

My question is on insulation, I’ve read you recommend a ceiling and insulating above that with a vented ridge.

So… if this is not going to be a building I heat 24/7 and never cool. Can I get by with reflectix under the metal roofing and insulating between the purlins with unfaced insulation, if I’m only going to heat it when I’m in it during the winter (heat with a wood stove).

Your post says if I do it this way I need to construct an air gap between the purlins and the roofing material, given the above scenario do I need this air gap if I only heat it a few times a week during the day? Obviously if I do need the air gap the ceiling would be a better way to go. LEE in IDAHO FALLS

DEAR LEE: Code does require airflow above insulation from eave to ridge with this scenario. An option might be to use two inches of closed cell spray foam insulation applied directly to roof steel underside. This would eliminate a need for a Reflective Radiant Barrier as well as ventilation above it. Closed cell spray foam should run roughly two dollars per square foot of roof surface and provide about R-13.

Advantage of a ceiling with insulation blown in is you only heat area below ceiling. Should you or some future user decide to climate control, this would provide a big start.

 

DEAR POLE BARN GURU: Can you build a pole barn at the bottom of a leach field? TRACE in JAMUL

DEAR TRACE: Yes you can. Typically most jurisdictions require any non-full foundation buildings to be at least 10 feet from any leach line. Consult with your local Health Department for requirements for your jurisdiction.

 

 

 

 

Raised Floor Over Crawl Space, Engineered Plans, and a Pool House

This week the Pole Barn Guru answers questions about a raised floor over a crawl space, purchase of engineer sealed plans, and moisture issues in an above ground pool house.

DEAR POLE BARN GURU: Appreciate all the information on your website very awesome it’s a lot to take in we are thinking of building a pole barn home and we have one question we typically don’t like concrete floors. I joist, does anybody just frame out floor joist, has with a 3 in rat slab for crawl space? GARY

DEAR GARY: Thank you for your kind words.

I would rather not live on a concrete slab either. One of our retired Building Designers has been putting up a hunting cabin done exactly as you envision:

https://www.hansenpolebuildings.com/2019/03/development-of-my-cabin-plans/
https://www.hansenpolebuildings.com/2019/03/pole-barn-cabin-part-ii/

https://www.hansenpolebuildings.com/2019/04/my-pole-barn-cabin-part-iii/
https://www.hansenpolebuildings.com/2019/03/participating-in-ricks-post-frame-cabin-planning/

Engineer sealed pole barnDEAR POLE BARN GURU: Do you sell only engineered plans for your building? I am interested in PROJECT# 06-0602 but I do not want to buy a kit.

Thanks! MATT

DEAR MATT: Thank you very much for your interest. Our independent third-party engineers will only provide sealed plans for buildings where we are providing materials, as there is no other way they can guarantee materials as specified actually arrive at your building site. Some of these are manufactured specifically for Hansen Pole Buildings, so there is no other method to acquire them. Frankly, our massive buying power allows us to acquire components at far better prices than you will be able to find and our low overhead and narrow profit margins allow for us to be extremely competitive, even with lesser quality providers.

 

DEAR POLE BARN GURU: Hello, I’m researching putting an above ground pool in a pole barn for my swim school. I live in Oregon so my biggest concern is mold in the colder months. Do you have any ideas on this & what type of doors & windows would you suggest? It will be a 12×24 heated salt water pool. Thank you, HANNAH in HOOD RIVER

DEAR HANNAH: Thank you very much for your interest in a new Hansen Pole Building. This article should be an assist to you: https://www.hansenpolebuildings.com/2019/08/post-frame-indoor-swimming-pool-considerations/. Our factory pre-painted commercial steel entry doors and vinyl windows should work well with a proper HVAC system.

 

 

 

 

 

Cabin Design Over a Crawl Space

Loyal readers may recall recent articles guest written by recently retired Hansen Pole Buildings’ Designer Rick Carr as he designed and erected his post frame hunting cabin over a crawl space (his journey began here: https://www.hansenpolebuildings.com/2019/03/development-of-my-cabin-plans/).

Today ROB in DENVER writes:

“Hi Mike.  I was given your contact info by one of your designers; she suggested I contact you with my questions.

 I’m currently looking at options to put up a cabin in Colorado.  The location is up near Leadville at around 10,000’ elevation and the soil (I’m told by local engineering) does not have much clay; it is more a mixture of sand and rock.  Frost level up there is 4’ down.

 Question A):

 I’ve checked out some of the construction options Hansen lists and I like the option of a pole foundation but I’m a little concerned about possible shifting due to temperature changes, etc.  I definitely would want to do a raised/suspended floor with crawl space underneath (rather than building on slab).  The cabin size I’d like to build is about 24×48’ and I don’t want to have to chase it going “caterpillar” downstream since I’d have no way to raise/lower points if they’re locked into poles.

 Do you have any data/literature you could point me to and/or just provide anecdotal background from your experience putting in these types of cabins under these conditions?  I’d actually like to go 2 floors but I’m then concerned about the additional load it might put onto these poles.

Question B):  My other concern is critters tunneling in and making an unwanted home in the crawl space.  If I’m not going with concrete pad and/or block stem wall foundation around the edges, what means are available to prevent animals from digging under any skirting I’d put on and making their home in the warmer space underneath?

Thanks in advance.”

Mike the Pole Barn Guru responds:

Thank you very much for reaching out to me. We are used to dealing with all sorts of rather extreme conditions, especially temperature change, since we can go from -40 to 110 where we are located.

Question A: Temperature changes are not going to perceptibly cause any shifting of columns, unless you had conditions where frost depth would be greater than four feet and there was enough water in your soil to create a frost heave. Given soil with little or no clay, it is probably a non-issue.

Building columns are actually very strong loaded vertically. We have a lakefront home outside of Spokane, Washington where our 22′ x 24′ garage sits on 14 feet of grade change. Soils are similar in condition to what you describe. Our garage has a four inch thick concrete floor on top of a wood framework 14 feet above grade on downhill side. Above garage level we have attic trusses with a bonus room we use as office space. Below the garage level we have a 16′ x 22′ studio apartment. This building is now 30 years old and has performed admirably with no noticeable settling or column movements, even with two SUVs parked inside. I would have no undue concerns of two stories in your setting.

Question B: You could do what I did and stop the siding at the bottom of floor framing, covering underside of floor joists with OSB, plywood, T1-11 or even steel siding. In Michigan we have run into a “rat wall” ordinance on occasion: https://www.hansenpolebuildings.com/2012/06/rat-wall/. Besides solutions offered within the article, one could also use a metal rat wall – constructed out of quarter or half inch mesh (aka hardware cloth). Rolls of mesh are typically three feet wide, so you could dig a trench around your building perimeter two feet deep and a foot in width. Attach top edge to inside of pressure preservative treated splash plank then down and out into trench. Overlap at any splices and use a separate piece on each corner to provide seam corners.

Good Luck! And let me know what you did and how it worked out.

Solutions to Porch Overhang Clearance Issues

Recently KIM in STRATFORD posted this question to a Facebook Barndominium discussion group I am a member of:

“I am trying to finalize my plans today. Is it possible to have 8′ side walls and still have a 6′ overhang open porch on the eave side of the house? I have a 5/12 pitch on the house portion and actually wanted two separate roof lines, one for the house and a separate one for the porch overhang. House is on a slab so no built up foundation walls. I’m not sure if this porch will be too low with the porch roof UNDER the house roof and with a slight slope for water drainage…. Any experts out here?”

Mike the Pole Barn Guru responds:

For starters, most steel roofing suppliers will not warrant steel placed on slopes of less than  3/12. Continuing out from your main wall six feet at a 3/12 slope will place underside of your overhang at roughly six feet and six inches. Not only could this become a head ringer (at least for my son who is 6’6” tall in his bare feet), but it is going to block clear view out windows in this area. It is also just plane going to feel low.

I did some researching, however I’ve been unable to find a Building Code requirement for clearance below an overhang, however I would have to believe seven foot to be a bare practical minimum. 

You could:

(a) Build over a crawl space, instead of a slab – raising elevation of home and affording a more comfortable surface to live on (https://www.hansenpolebuildings.com/2019/03/slab-on-grade-or-crawl-space/) ;

(b) Increase house wall height – you could maintain an 8′ finished ceiling and have raised heel roof trusses to allow for full depth attic insulation from wall-to-wall (very good idea) https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/ ;

(c) Use roof trusses wide enough to span from opposite wall to outside edge of porch, with a pitch change at junction between porch and home.

Dial 1(866)200-9657 and ask to speak to a Building Designer. Your call is free and we have great solutions for you.

Thoughts on a Floor

Thoughts on a Floor:  

Brought to you by reader ANDREW in LEBANON:

“Hi! I am looking at purchasing a post frame building to use as a new home. We are well on our way with being under contract for the land and one of your recommended builders is meeting me at the site this week to make sure the land is good/flat enough.

I will be hiring the construction of the exterior and then build the interior myself.

With that said, here is my question (I will do my best to describe it by typing.) Instead of pouring a huge concrete slab (building will be 60×96), I want to do a typical crawl space to be easier to run plumbing and such, plus make changes as needed. Also, concrete slabs are expensive, especially for 5,000+ sqft. What are your thoughts? I will run 2×10 side by side (doubled up) the entire 96′ length supported every 12′ by concrete footers and building columns. This will be roughly 24″ from the ground (haven’t fully decided on the height yet). Along with that, going to 60′ width, I will use 2×8, 16″ OC. I forgot to mention, along the inside perimeter of the posts, I will be running 2x10s attached to the posts. The ends will have the 2×10 laying on top (along with concrete/building posts every 12′), and the joist ends resting on the eave sides.

With all that said (hopefully legible and not rambling), what do you think? I think it is a pretty solid plan and will not only save a lot of money by not doing a slab, I will effectively have a crawlspace. Yes, I know this will raise the entry points so the door looks like it will be off the ground 3+ feet, but I will be putting a decent sized deck on the front as well as a smaller one on the rear point of egress. A quick reply would be greatly appreciated so I can hopefully discuss more with the builder as well as for my own personal planning purposes. Thanks a lot!”

DEAR ANDREW:  I am a fan of living on wood instead of concrete, so crawl space makes total sense to me.

The right way to do this is to have your floor incorporated into the original engineered plans for your building. This will assure you of several things – the footings will be designed with an adequate diameter to resist settling (last thing you want is to have a post or posts sink. It also will make sure the size of the members will be adequate to support the loads both from a weight bearing standpoint as well as deflection. Your doubled 2×10 idea for supporting the floor joists is hugely under designed and it is very possible it would create a failure condition, not something you want to have occur in your new home.

Floor deflection is an under discussed realm (you can read more here: https://www.hansenpolebuildings.com/2015/12/wood-floors-deflection-and-vibration/). 2×8 #2 at 16 inches on center and 2×10 #2 at 24 inches on center are going to have virtually the same spanning abilities as floor joists, however the 2×10 floor will meet L/480 requirements for deflection, while the 2×8 joists just barely meet the code minimum of L/360. The added plus – the 2×10 joisted floor takes 16% less board feet of lumber and is less expensive to build!