Tag Archives: sheathing

Attic Ventilation, Shearwall Stitch Screws, and Adding Sheathing

This week the Pole Barn Guru addresses reader questions about ventilation needed for a new attic with metal ceiling and blown-in insulation, a confirmation for endwall needing stitch screws for shear, and if adding sheathing to an existing pole building would add value.

DEAR POLE BARN GURU: I bought a house with a pole barn that is unfinished inside. The metal walls were not wrapped and the only insulation in the barn whatsoever is double bubble on the underside of the barn roof. I am going to have a metal ceiling put in and then blown fiberglass insulation for an R30 value in what will then be the attic. There is currently no ridge vent nor gable vents either so I am concerned about air flow in the attic once the metal ceiling and blown insulation are complete. The eaves have perforated soffit so I’m hoping even after the blown insulation is done that will provide an air flow into the attic. So am I correct to think that I need to have gable vents put at each end or a ridge vent so that there is positive air flow through the attic? Thanks! BILL in STEVENSVILLE

DEAR BILL: Your thinking is absolutely correct – you need an adequate ventilation exhaust point. Ideally, this would be at your ridge. Gable vents, while meeting code requirements, actually only provide good ventilation immediately closest to vent locations.

This article covers requirements for attic ventilation: https://www.hansenpolebuildings.com/2023/06/274512/

In Queen Anne’s County – you are in Climate Zone 4A. 2021’s IECC (International Energy Conservation Code) specifies R-60 for ceilings in your climate zone. As so much of your cost of blown insulation is having installers show up, you may want to consider going with a greater R value than originally planned. Energy costs are not ever going to go down (nor cost of insulating).


DEAR POLE BARN GURU: I have a rear end wall that is labeled shear wall that says I need an inch and a quarter number 12. Stitch screw 9 and 3/8 on center. Is that every 9 and 3/8 on center vertically on each overlap? DAMINA in TONOPAH

DEAR DAMIAN: You are correct. Panels stitched together have roughly twice as much shear capacity as do unstitched panels.


DEAR POLE BARN GURU: Question for you Guru! I bought a property with a small pole building/shed. Is there any value in adding sheathing? If so, how do you retroactively figure out if the roof will handle the additional load? JESSE

DEAR JESSE: If the roof steel is properly fastened (1-1/2″ screws in flats along one side of each high rib in field, #12 or #14 x 1-1/2″ screws both sides of each high rib at eave and ridge) chances are it will perform admirably without any sheathing. Think of steel roofing and siding as acting like very strong, very thin OSB or plywood.


Barndo Living, Bracing a Roof Only, and Housewrap

This week the Pole Barn Guru answers reader questions about “barndo living” and the how to’s of post frame construction in Pagosa Springs, CO, bracing a roof only structure for working cattle, and if sheathing and housewrap are needed for a post frame building using wet-set brackets.

DEAR POLE BARN GURU: Have you ever constructed any barndominium‘s in Pagosa Springs Colorado area? Also, ball park figure, what is the square foot price of finished barndo living space in this area. I’m talking very, very simple nothing fancy finishes. What do you mean DIY? Is that in reference to assembling the kit? And would we need something like an extended boom forklift to assemble it, or no need for such equipment? If we’re building something with 12 foot doors, so presumably need at least 2 more feet for roll up doors then even more for trusses, how would we do that without some sort of boom fork or crane? Scaffolding maybe? SAM in PAGOSA SPRINGS

DEAR SAM: I personally have never built in Colorado. Hansen Pole Buildings has provided nearly 300 fully engineered post frame buildings to our clients in Colorado. Chances are good, several are in your area.

Fully engineered post frame, modest tastes, totally DIY, move in ready, budget roughly $70-80 per sft of floor space for living areas, $35 for all others. Does not include land, site prep, utilities, permits.
DIY – as in Do It Yourself In most instances, no heavy equipment is required. Skid steer (aka Bobcat) with an auger is handy for digging holes.
For information on lifting trusses, please see: https://www.hansenpolebuildings.com/2019/11/winch-boxes-episode-v/


DEAR POLE BARN GURU: I’m building a steel truss kit just like this one for working cattle. To me it doesn’t seem very stable with just post in the ground. How’s the best way to brace this style of building? The long sides of the building will have guardrail 3 rails high down the side so I know that will help some but unsure of how to brace the gable ends. RICKY in KINGSPORT

DEAR RICKY: Provided your columns are adequately sized for the wind load and embedded in fully concrete filled holes, it should prove to be fairly stable (follow the recommendations of the engineer who designed the plans). Ideally, you would have enclosed endwalls so shear loads can transfer from roof to ground through them.


DEAR POLE BARN GURU: Was wondering if I could ask you a question I’m getting ready to build a barndo was going to use wet set brackets do you recommend me using sheeting on it as well or just house wrap? Having problems with this issue thanks. DOUG in INDIANA

DEAR DOUG: If your steel has adequate shear strength, then there is no structural reason to sheet it. Housewrap is a must unless you are planning on closed cell spray foam for insulation.

Here is some extended reading on Weather Resistant Barriers: https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/

ZIP Sheathing

ZIP Sheathing and Other Post Frame Thoughts

Reader SPENCER in WINLOCK writes:

“Hello, I’m in the planning phase and your roof purlin style and watching the “Hart and Home” youtube series have just about convinced me to go with Hansen buildings. I have a few general questions. 1. I have a tight driveway with a gate. What kind of a truck would 40′ trusses be delivered on? 2. I’d like to use zip panels on my walls and roof for sheathing below the metal. Is this something that can be added to the engineering package and supplied by me? I’m assuming the weight of the panels would need to be accounted for in the roof loading. 3. Are 20′ side walls a possibility with your buildings? 4. I’d like to use poured columns and wet set brackets for my footings. Is this something that can be added to the engineering package and supplied by me? My goal would be to have these installed well before taking delivery of the building. 5. I’d like to do a lean-to but need to keep as much roof height as possible for a 14′ door. Do these have to be designed with trusses or can I specify dimensional lumber? Thank you!”

Mike the Pole Barn Guru responds:

For those following along at home – Hart and Homes YouTube series can be viewed here: https://www.youtube.com/channel/UCjzEsuHQ8UFZEbXQc16RT9Q

Hansen Pole Buildings has provided more fully engineered post frame buildings to our clients in Washington State (roughly a 1000 at last count), than any other state. Mr. and Mrs. Hart are a great couple and have been a pleasure to work with. This roof purlin style (purlins on edge) is fairly typical in Western U.S. post frame buildings, however, recessing them between trusses with joist hangers is not. Our feeling is this engineered connection is far superior to attaching purlins to a very small block full of nails (extended reading on paddle blocks can be found here https://www.hansenpolebuildings.com/2012/05/paddle-blocks/).

In answer to your questions:

1) Regardless of supplier, both roof trusses and steel roofing/siding are typically delivered by semi-trucks pulling 48′ trailers. You may want to make provision to have a utility trailer handy for at least a steel package to be off loaded onto, should you feel your entrance is just too tight for this sort of truck/trailer combination.

2) Zip System sheathing was introduced by Huber Engineered Woods in 2008 and it has been widely adopted in many U.S. states. Huber manufactures premium OSB products such as Advantech sheathing. Many builders prefer Advantech over plywood, due in part to quality problems they were seeing in plywood.

Zip System sheathing’s chief virtue is it marries a water-resistant barrier (WRB) to sheathing, eliminating the step of adding a separate WRB. Many builders like the Zip system a lot because it eliminates what has always been a troublesome step in building processes. This is, carefully installing large plastic sheets around an entire building, carefully lapping it at seams, and more carefully cutting and taping around doors and windows so it directs any water to the exterior.

While Tyvek (first popular building wrap), was originally marketed as an energy-saving material, it was soon disproven that a building with Tyvek, installed typically, wasn’t much tighter than a conventional building with asphalt felt.

A building built with Zip sheathing, however, taped and sealed as recommended, produces very tight results without a lot of fussing. This is especially true in relatively simple building plans without a lot of bumps, angles, and complex shapes.

Main Zip Sheathing downside is a heavy reliance on flashing tape. Huber makes high-quality tape in various widths and also makes a stretch version for window pan flashing and other tricky details. Still, water, frost, or dirt can undermine a watertight seal, as can sloppy installation.

Liquid-applied sealants offer an alternative to tape and is gaining in popularity. One example is Huber’s Liquid Flash, a thick liquid flashing applied with a caulking gun and spread with a trowel. Liquid flashing provides a nearly foolproof solution for waterproofing window pans, foundation joints, and other tricky or vulnerable transitions.

Like any product or system Zip sheathing has pros and cons. Some are actual and proven, some more theoretical. This product has not really been around long enough to stand time’s test. But, there are few in field failure reports and most contractors who have tried this system are happy with it overall.

Here are main arguments, pro and con:


  • Installs sheathing and water-resistant barrier in one step. Saves labor.
  • Makes it relatively easy to create a very tight shell.
  • This is a complete system with high quality tapes and liquid sealant, as well as published details backed by a reputable company.
  • Backed by a 30 year warranty, but not transferable, and subject to usual conditions about proper installation.
  • Window installation and flashing is easier than with building wrap (but relies on tape at window head flashing). Eliminates Origami style building wrap folding.
  • Quick dry-in for contractor with less concern about wind and water.


  • Tape must be installed carefully without dirt, frost, or moisture to seal well.
  • Horizontal seams are vulnerable to water penetration if tape fails. This is especially a concern at door and window tops.
  • Less permeable to moisture than most building wraps, so in theory the wall may not dry out as easily.
  • Not a true drainage plane, as can be created with draining building wraps. Vertical spacers or a second building wrap layer would be needed for a true drainage plane.
  • If nails are overdriven, especially “shiners” missing framing, OSB is exposed and needs sealing with tape or sealant.
  • More expensive materials (but savings on labor).
  • On a roof, especially, I would be reluctant to trust tape to prevent leaks, so would want another roofing felt or synthetic underlayment layer.
  • I would not want to screw roof steel to any OSB product.

Many builders like Zip system’s simplicity. To a large extent, its long-term performance depends on taped seam durability. If applied to a clean surface with a roller, as recommended, all indications are it will provide a long service life. This is a high-performance tape. Still,  it is partly a matter of faith it will remain water tight for decades.

Alternatively, building wrap does not last forever either. It tends to get brittle and deteriorate over time. It can deteriorate rapidly if it stays wet due to trapped water — for example, if a building wrap section gets bunched up behind a trim piece as I have seen around windows, corner boards and other exterior trim.

With any waterproofing product, workmanship quality is at least as important as material. A building built well with steel siding over plastic building wrap can perform as well as one with Zip sheathing. It just a careful detailing matter — especially  around doors, windows, and other joints prone to leakage.

With all of this said, yes, you could provide your own Zip sheathing and we can incorporate it in your engineer sealed plans.

3) We can provide eave sidewalls to 40 feet tall and three stories (50 feet and four stories with fire suppression sprinklers).

4) We engineer many of our buildings using poured piers and wet-set brackets. We typically provide brackets as ours have an ICC ESR Code approval and we ship them out to you far in advance of your building shell materials.

5) Our default for attached lean-to roofs would be rafters as opposed to mono-pitch trusses.

Where Your Barndominium Dollars Go

Where Your Barndominium Dollars Go

Recently published by NAHB (National Association of Home Builders) was their 2019 Cost of Construction Survey. I will work from their ‘average numbers’ to breakdown costs so you can get a feel for where your barndominium, shouse or post frame home dollars go.

Please use this as a reference only, as chances are your barndominium, shouse or post frame home will be anything but average!

2019’s average home had 2594 square feet of finished space and a sales price of $485,128. Without lot costs, general contractor’s overhead and profit actual construction costs were $296,652 ($114 per square foot).

Construction Cost Breakdowns as Follows:

Site Work

Building Permit Fees                                                                                  $5,086

Impact Fees                                                                                                   3,865
Water & Sewer Fees                                                                                     4,319

Architecture, Engineering                                                                           4,335

Other                                                                                                                 719


Excavation, Foundation, Concrete, Retaining walls and Backfill        $33,511

Other                                                                                                                1,338


Framing (including roof)                                                                            $40,612

Trusses (if not included above)                                                                     6,276

Sheathing (if not included above)                                                                 3,216

General Metal, Steel                                                                                           954

Other                                                                                                                     530

                       Exterior Finishes   

Exterior Wall Finish                                                                                   $19,319

Roofing                                                                                                          9,954

Windows and Doors (including garage door)                                       11,747

Other                                                                                                                671

                       Major Systems Rough-Ins       

Plumbing (except fixtures)                                                                        $14,745

Electrical (except fixtures)                                                                           13,798

HVAC                                                                                                               14,111    

Other                                                                                                                 1,013

                       Interior Finishes       

Insulation                                                                                                  $ 5,184

Drywall                                                                                                        10,634

Interior Trims, Doors and Mirrors                                                           10,605

Painting                                                                                                         8,254

Lighting                                                                                                         3,437

Cabinets, Countertops                                                                             13,540

Appliances                                                                                                    4,710

Plumbing Fixtures                                                                                       4,108

Fireplace                                                                                                       1,867

Other                                                                                                                923

                                              Final Steps

Landscaping                                                                                              $6,506

Outdoor Structures (deck, patio, porches)                                           3,547

Driveway                                                                                                     6,674

Clean Up                                                                                                     2,988

Other                                                                                                              402

Other                                                                                                      $11,156

Considering using post frame construction, rather than stick built and foundation costs will decrease by roughly $10,000 (https://www.hansenpolebuildings.com/2011/10/buildings-why-not-stick-frame-construction/).

Architecture, Engineering, Framing and Exterior Finishes for this average home run an astonishing (to me) $97,614. If labor runs 60% of material costs, this would put a material package at $58,300! At over $20 per square foot, this would be one very, very nice post frame barndominium!

Looking to stretch your barndominium dollars? Considering Doing-It-Yourself, you absolutely can do it!

Free Post Frame Foundation Building Calculator

Free Post-Frame Building Foundation Engineering Calculator

No, such a thing as a free post-frame building foundation engineering calculator does not exist. However there always seems to be someone out there who is in search of “engineering for free”.

Reader KELLY writes:


Do you have a link to a pole foundation engineering calculator?

Looking for column depth / diameter for:


10 ft column spacing

35 PFS load

115 wind load.

No floor for constraint.


Mike the Pole Barn Guru responds:

There is no such thing as a “pole foundation engineering calculator” therefore, there is also no link to one. The design of post frame (pole) building foundations is one which is best left in the hands of RDPs (Registered Design Professionals – architects or engineers). When provided with all the pertinent information about your proposed building, they can design not only a structurally sound column embedment, but also your entire structure (which I whole heartedly recommend).

You’ve provided some of the information a RDP would require, but I will expand upon it:

Will the building have adequate sheathing (which could be roll formed steel roofing and siding) to transfer wind loads from roof to ground through endwalls? And will the sheathing be adequately fastened to underlying frame to take advantage of sheathing stiffness? If yes, diaphragm design can be utilized in your building design.

The difference in forces carried by sidewall columns with and without an adequate diaphragm is a factor of 4! If diaphragm design cannot be utilized, expect significantly larger columns, deeper holes and more concrete around columns.

What type of soil is at building site? Strength and stiffness of your soil will impact both depth and diameter of holes.

How are you measuring your 14′? It should be from bottom of pressure preservative treated splash plank, to underside of roofing at sidewalls. It does make a difference.

Does your building have overhangs?

What is the roof slope?

What is wind exposure at your site? The difference in force against columns between Exposure B and Exposure C is roughly 20%.

In the event you are not interested in procuring services of a RDP, the NFBA (National Frame Building Association) has available a Post-Frame Design Manual and you could attempt to do calculations yourself. For more information please see: https://www.hansenpolebuildings.com/2015/03/post-frame-building-3/.

Of course you could always invest in a fully engineered post frame building kit package. Besides engineer sealed blueprints and calculations, you would also get materials delivered to your site and a multi-hundred page Construction Manual to guide you through to a successful completion.