Tag Archives: roof steel

To Learn More, A Roof Steel Replacement, and Ideal Height

An Engineer wants to Learn More, Roof Steel Replacement, and the ideal Building Height to Accommodate an RV!

DEAR POLE BARN GURU: I’m a licensed engineer in KY. I would like to learn more about pole barn design. Do you have any references that you would recommend? James in KY

DEAR JAMES: The NFBA Post Frame Building Design manual is probably your best structural reference. https://www.hansenpolebuildings.com/2015/03/post-frame-building-3/


DEAR POLE BARN GURU: Hello. I have a Hansen building I bought in 2005 as a kit. I am planning on installing a new roof on the higher 18′ 40×35 long section. The original roof over the vaulted ceiling has leaked since day one, as the contractor did a very poor job. I’m thinking of doing a snap lock standing seam type with no exposed fasteners. To my surprise two contractors have suggested pulling the existing sheeting and replacing the standing seam( 24 ga), but no underlayment.

I thought the screwed down panels provided shear strength and rigidity to the structure.


Construction MistakeDEAR BRYAN: Indeed, standing seam steel has no shear carrying capacity, as such it should always be installed over 5/8″ or thicker CDX plywood (not OSB). However, chances are your trusses are not designed to support the added weight of the plywood. Depending upon what the exact nature of the poor installation is, the solution might be as simple as replacing offending screws with longer, larger diameter parts (if original screws were merely poorly seated). If the screws were not predrilled (therefore causing screws to either barely hit or miss roof purlins entirely), then new 29 gauge through screwed steel with properly installed screws should solve the challenges (and be phenomenally less expensive).


DEAR POLE BARN GURU: Looking to build a pole barn with 14ft height door for a RV. What would the overall height of the building be? Thanks JON in PERRYSBURG

DEAR JON: With a sliding door (not my recommendation) if your building has no endwall overhangs, then 15 foot eave height will work; with end overhangs 15’6” or 15’8” depending upon the dimension of the roof purlins.

Going to a sectional overhead door, allowing for an electric opener your eave height is most likely going to be 16’6”.

If you are planning on climate controlling the building and having a ceiling (smart choices), then the eave height will need to be further increased by the amount of roof truss heel height greater than the most common six inches.



Eave height is relatively inexpensive, don’t scrimp to try to save a few bucks and be sorry because you end up with a design solution which is less than ideal (aka a sliding door) or an overhead sectional door which will not accept an opener.

Considering a Pole Barn, Roof Loads, and Proper Ventilation

DEAR POLE BARN GURU: Good morning.

I am considering building a pole barn on our land in northwest Georgia and wanted to know the following:

1) On your website, you list links for residential, agricultural, and commercial buildings.  What is the difference between a those three types of buildings?  Are they different because of design or do they each involve different construction materials?  Do the commercial buildings use a lower gauge (thicker) sheet of metal for siding than a residential building?

2) Do you have any product comparison documentation between your kits and the other pole barn kits on the market (DIY, Menards, etc.)?  Interested specifically in design, material, and construction comparisons.

3) Would your pole barn kits be able to accommodate a chimney/stove pipe if I wanted to use a wood burning stove for heat?


About Hansen BuildingsDEAR CHRIS: The differences for residential, agricultural and commercial buildings shown on our website are for the convenience of those who are looking for a particular end use, it keeps from having to browse through a plethora of photos of buildings which may not be what one is looking for. The construction materials and methods used are going to be individually tailored to the ultimate end needs of each client, as well as the climactic conditions of a particular site.

Our goal is to custom design for you a building which best meets your wants, needs and budget. We are so confident in our ability to provide the best possible value for your post frame building investment, once this is done, we would happily shop this building for you with any other provider or providers you so desire. How easy is this?

(BTW – Menards might be a bit geographically challenging as their nearest location to you is in Owensboro, KY)

Actually any post frame building (not just a Hansen Pole Building) can accommodate a chimney/stove pipe with the use of a Dektite® (read more here: https://www.hansenpolebuildings.com/2012/09/dektite/).


DEAR POLE BARN GURU: I have a 30 year old pole barn that is 30’ x 40’ x 9’ tall. It has a metal roof, trusses are 4’ on center. Can I tear off the metal on the roof and put down OSB and shingles? JIM in LAWTON

DEAR JIM: Chances are excellent your existing roof system is not designed to support the weight of OSB and shingles, as most pole barn (post frame) trusses are designed for a dead load of only 3 to 5 psf (pounds per square foot) which includes the weight of the trusses themselves plus the roof purlins. Steel roofing weighs in at under one pound per square foot. 7/16″ OSB comes in at roughly 1.5 psf, 15# felt and shingles 2.5 psf making the weight combination more than four times greater than the steel.

The big question is – why? Even “lifetime” shingles will usually last only about 15 years and you know the steel roofing you have had made it twice as long. Steel is far more impervious to weather (especially hail) and readily sheds snow, unlike shingles. For my money, if I had to re-roof I would invest in steel roofing with a high quality paint system like Kynar. Read more about Kynar here: https://www.hansenpolebuildings.com/2014/05/kynar/.


DEAR POLE BARN GURU: I have a pole building with all metal sheeting. The interior walls are framed and insulated R13 batt. The ceiling is insulated with 1/2 foam a 3/4″ air gap then R19 on top. The underside of the roof is not insulated. I have eave ridge vent. Building is heated in winter. Can I exhaust fumes (paint,lawnmower,etc.) into the attic space and let it vent out the ridge or will I be causing a condensation problem? I will use a standard box fan to blow exhaust into the attic space. I’m also hoping to do this to help melt snow off the roof.

crash-test-dummy-symbolDEAR RICH: I’ve seriously struggled with your question for several weeks now. It lead me to spend hours researching the International Mechanical Code (I am proficient in the IRC and IBC, but not the IMC), looking for backup as to your scenario. In the end it all comes down to this – WHY would you want to dump toxic fumes and their waste into your attic? At some point this has got to be just plain unhealthy.

Whether you do or do not blow exhausts into your attic, your building has the strong potential for a condensation problem because there is no thermal break below the roof steel. You should look at having closed cell spray foam installed on the underside of the roof steel.

As to the heat from the exhaust helping to melt snow off the roof – do not count on it, by the time it gets into your attic, the heat generated will be minimal at best.

Rusted Roof on Pole Barn

Rusted Roof on Old Pole Barn

Reader DAVE in GRANDVILLE writes: “I have a technical question.

I have a older Hansen pole barn that previous homeowners had built. Guessing 20yrs old +/-.
Roof is showing approx 75% rusted with no paint left and all steel on bld. is 50% gone as well.
I’m looking to give it a facelift/remodel for cosmetic/function due to minor roof leaking starting.
1. Is there a product available to apply over existing steel roof before have new roof completed? Thoughts: roofing paper, ice/water barrier or something of this nature? This would eliminate need to remove current steel roof that’s insulated beneath steel.
Good idea or bad? Please way in on thought.
2. Is there a alternate paint/epoxy type option for something of this nature vs replacement with new? If so what?”

Mike the Pole Barn Guru writes:

It is actually highly doubtful for your building to be a Hansen Pole Building, as we have only been in business since 2002 and did not deliver a building into your state until about 10 years ago. In any case, it sounds like you need some assistance. Unless you are in a highly corrosive atmosphere, it would be unusual for even basic polyester paint to experience the type of deterioration you describe. At 30 or more years of age, it would be more of a possibility.

It would probably be a bad idea to try to roof over the existing roof steel as the screw fastener heads would be in the way. If you feel leaving the roof in place is the only option, you could probably run 2×4 nailers placed flat on the roof every two feet (parallel to the ribs of the roof steel), using a pair of three inch or longer hot dipped galvanized ring shank nails through the nailer, through the existing roofing and into the roof purlins below. Then 2×4 could be placed flat every two feet going the length of the building (again attached with the same nailing as above) to screw the new roofing to.

This solution would also entail adding some sort of new rake and eave trims to keep critters from flying in between layers of roofing and making a home there.

A company called Conklin Products does offer what is purported to be a complete waterproofing system for metal roofs which is advertised to stop leaks and inhibit rust. I have not personally used this product, so it is not an endorsement: https://www.conklin.com/productinformation.cfm?line_id=07,08&pl=02&catID=08&plname=Roof%20Coatings&.

If it was my own roof, I would peel off the existing steel and replace with new steel roofing – which has the best possible warranty against fading and chalking. If available, this is my paint finish of choice: https://www.hansenpolebuildings.com/2014/05/kynar/.

Spokane? Roof Steel Starts? and Winging It!

DEAR POLE BARN GURU: Your from Spokane area? Can one construct a custom pole building as home Spokane county? Would you have any references of builders in my area to consider? TERRY in MEAD

DEAR TERRY: Yes, I was born and raised in Spokane – still have a plethora of family members there (as well as a home).

You (as well as anyone else) can construct a post frame (pole building) home anywhere in the United States. Post frame buildings are totally Code conforming structures. Keep in mind you WILL have to have engineering for your building, which is why it is most beneficial to deal with a building provider who can get engineer sealed plans for you to obtain your Building permit.

The builders we refer are what is known as “technicians” – they are the people who swing hammers and drive nails and screws. They are generally unqualified to assist you through the design phase of your proposed project. Once you have determined the features which best meet your needs for space and your budget, we can provide names of several who you can then vet to determine which will be the fit for you.

DEAR POLE BARN GURU: I have a question on first roof metal sheet. How far do I overlap the end soffit fascia board? BILLY in VENICE

DEAR BILLY: The leading edge of the first panel of roof steel should fall directly dead center of the varge rafter. It should not, in any case, extend beyond the rafter.

DEAR POLE BARN GURU: I am looking to build a 20’x12′ pole barn style roof/structure overtop a deck adjoining to 12’x12′ shed all next to a concrete deck/pool. The deck will be connected to the 12’x12′ shed, sharing same roof with having a 4:12 pitch metal roofing on 2×4 perlins. Shed will be 2×4 framed, 2×6 floor joists/frame, 2×6 rafters, 12″ o.c. My deck plan is 2×6 PT framed wrapping around 6×6 posts and using 10 post support pier blocks (6 in middle spaced every 3rd joist and 1 each between 6×6 post to support 2×6 frame). Will that suffice?

– can I use 6×6 PT posts 10′ o.c. with a single 2×12 notched into 6×6 for top header? Or would doubled 2x12s be needed (notched)
– 10 engineered trusses 24″ o.c. on 2×12 header? Or doubled trusses at posts—giving 6 total trusses

Thank you. Your site is very informative. RYAN in MOUNT HOLLY

RYAN: In a nutshell – no, your ideas will not be structurally sufficient. This is one of the reasons the State of New Jersey requires engineer sealed plans for all structures – it is the insurance every building is designed to meet with the requirements of the Building Codes and to protect you and your loved ones from the consequences of the unexpected collapse of some or all of your building.


Consider Post Frame for New Home!

DEAR POLE BARN GURU: Good morning. My name is Thomas and I am with xxxxxx; we manufacture metal roofing and siding and based out of Tennessee. I wanted to ask you a few questions to gain some information. First, my wife and I are starting to look at metal building for our new home, is this something your company is licensed to do in the state of Tennessee; second, I also would like to know if you manufacture your own metal roofing and siding, or if it is purchased from another company. Hope you had a great Christmas and I look forward to hearing back from you. THOMAS in MURFREESBORO

DEAR THOMAS: Thank you for your inquiry. Hansen Pole Buildings provides engineered post frame buildings in all 50 states, including Tennessee. Post frame (pole) building homes have become quite popular in the past few years and chances are excellent we can provide a customized building shell which will ideally meet with your needs and budget. We outsource our metal roofing and siding and we can provide the building sans roofing and siding in the event you should wish to provide your own.

DEAR POLE BARN GURU: I have submitted a request for a quote on our residence but I’ve needed to make a few modifications. How important is post spacing on a residential post frame building? The residence I’m designing is based on nominal 8′ post spacing but with the interior design I have, a couple of the posts interfere with window/door placement. I’ve been assuming that as long as opposite side posts are aligned so that the trusses are supported, the post position can be varied somewhat. On our design, I’ve assumed nominal 8′ post spacing but actual spacing winds up being as close as 7′ and as wide as 10′ 6″. Can irregular post spacing be accommodated or do I need to modify our interior design? Thanks LONNIE in COLORADO SPRINGS

DEAR LONNIE: Your assumption, “as long as opposite side posts are aligned so that the trusses are supported, the post position can be varied somewhat” is absolutely correct. In most circumstancing having the sidewall columns spaced at 12 foot on center is your most economical, so anything at this spacing or less should not be an issue from an engineering and design standpoint. When you arrive at an ideal spacing, please make sure it is listed on any quotes and invoices, otherwise there is always the possibility of columns being reorganized to the most cost effective combination.

DEAR POLE BARN GURU: Is there a recommended distance from the peak of a roof that the top purlin is installed, and why? WILL in NEWPORT

DEAR WILL: Yes there is a recommended distance. Here is the applicable excerpt from the Hansen Pole Buildings’ Construction Manual:

With standard steel ridge caps, the ridge purlin “uphill” side can be no closer to peak than five inches. This may result in space between ridge purlin and next purlin “downhill” being decreased. Ridge purlins can be further from truss peak than the minimum distances, without negatively affecting building. Roof ridge caps attach to roof steel with metal-to-metal screws, not to ridge purlins, so ridge purlins need not align with future ridge cap fastener locations.

If ridge purlins are “uphill” further than this, roof steel may not have an adequate overhang at eave and challenging situations will result!”

Hansen Buildings Tech Support

What Real Life Technical Support Sounds Like

Many of us have had situations where we needed to contact a company we have purchased a product from for some technical assistance. I know when I have done so, every once in a while I am thankfully surprised to have the person I am dealing with actually have a grasp of the English language.

Here is what the Hansen Pole Buildings Technical Support team is like in real life:

Client: Plans call for wing roof steel to extend past column when there is an overhang. With the provided length of roof steel, this leaves a short section at the top, uncovered. What is the plan, to cover with trim? What trim is recommended? Is there an option to have a longer piece (x4) to extend to the top of the varge rafter?” (Author’s Note: This happens to be a monitor style building, with a raised center clearspan and dropped sheds – or wings – on each side) Tech Support: “Thank you for utilizing the Hansen Pole Buildings Technical Support Department.

In review of your plans, the wings extend horizontally from the main building columns, to the wing Building Lines 12′. The overhang past the wing Building Line is 1′, fascia board is 1-1/2″ and the steel should extend 1-1/2″ past the fascia.

Summing these up = `13.25′ X the roof slope factor for 4/12 (1.0541) = 13.96′

The steel provided for the wing roofs of your building is 14’2.5″ in length, which is more than ample to cover the roof surface.

Where the wing purlins overhang the endwall, the steel will project upwards (towards the raised center) by 2.5″ past the uphill side of the highest purlin. A piece of LG-126A (1-1/2″ x 5-1/2″ L Trim) has been provided to cover the wide face and bottom edge of the extended top purlin to protect it from the weather.

In the event the roof steel does not appear to be long enough to allow for this coverage, please (a) measure the length of the steel and/or (b) verify the dimensions of the wing as 12′ and overhang as 1′. If the steel is short, please contact Justine@HansenPoleBuildings.com for prompt resolution.” There is, of course, the possibility the overhangs were cut a bit longer than anticipated by the plans. If so, it is an easy fix, before the steel is applied. This is one more reason the entire roof is to be framed and covered prior to any wall coverings – it would be far more complex to make changes to the overhangs and any soffit supports with the wall steel in place.

Real life tech support comes from not a myriad of people who have canned answers which may or may not be helpful, but in our business one of three people. The majority are answered by myself, the Pole Barn Guru, with over 35 years of experience and 14,000 pole buildings. Second, by Eric, one of the two business owners, and third, by Justine, Hansen Buildings’ materials buyer. All three of us answer emails and texts virtually 24/7. We value our clients and want every one of them to have The Ultimate Post Frame Experience.