Tag Archives: steel roof

Steel Roofs Are Not Meant to Be Weather Tight?

Once upon a time I was a post frame building contractor. With as many as 35 crews erecting buildings in six states, we erected thousands upon thousands of buildings. If we would ever have told a client, “Steel roofs are not meant to be weather tight” it might (and should) have been our last job! Our Quality Control team would check in with each client every three months, post completion, to ensure they were satisfied and had no leaks. We actually warranted our workmanship against roof leaks for five years.

Reader STEVE in ROCKFORD writes:

“Hi, 

I had a local crew put a new 29ga pro-rib steel roof on my older pole barn.   Since then we have had a couple storms come through, one was very heavy wind and rain, and all was good, building was good.   The next was a light drizzle, and the roof leaks at the ridge cap – it looks like the leak was coming from the screw, not the top of the sheet. The next day I went up to take a look.  It looks like they screwed the ridge cap down the upper purlin next to the rib, and not into the rib.    Is this a problem?  How can I fix it?  A call to the contractor was no help, “that’s how we do them all, and they are not meant to be 100% weather tight” was the response.   It does have some kind of meshy vented like closure strip.”  

Under Illinois’ Roofing Industry Licensing Act, all contractors offering roof construction services must obtain a license from Illinois Department of Financial and Professional Regulation (IDFPR) before engaging in any work. This local crew needs to come and repair or replace their work so your roof is weather tight. I would recommend you spend $100 to have your attorney send a demand letter on Monday. Construction work comes with a minimum one year implied warranty on materials and labor, so as long as you are within this time frame, you have cause of action should he fail to repair. You can also file a complaint with your state (https://www.idfpr.com/Forms/Brochures/FilingAComplaint.pdf) –  you should do this immediately, as this contractor needs to be stopped before he rips off yet another innocent building owner with shoddy workmanship.


Your building’s ridge cap should have been attached to each roof steel high rib with a metal-to-metal stitch screw. Ridge cap to roofing screws should not be placed next to ribs.

How to Install a Steel Roof Over Shingles

How to Install a Steel Roof Over Shingles
Absolutely true story, with me as part of it! My lovely bride bought a raw weed covered property along the South Dakota shore of Lake Traverse in the early 1990’s. For a home, she had a double wide manufactured home set up on the property. A few years later, she had a 32 foot square stud framed garage added. Both the home and the garage had asphalt shingle roofing.
Between extreme temperatures from 100 F plus in summer to -40 F., some potent winds and occasional hail storms, this is a brutal climate for shingles. More than a few of them had broken or blown off.
Reader DAN from MOUNDS VIEW triggered this soliloquy with his message to me:
“I was reading past questions and the subject of metal roofs was brought up, which prompts this question.

We have a cabin that I intended to have a metal roof but didn’t get one. We are now getting close to needing a re-roof and I’d like to get metal on it.

The question is, when starting with an existing asphalt shingle roof, installed over, I believe 1/2 cdx, what should be done to prepare for the metal? FWIW, it’s a 10/12 pitch.

Thanks.”

Mike’s story:
Before sharing what we did I did my usual Google search to see if I could find someone else’s good advice. Ran across some scary stuff, so I felt compelled to share.

steel roofingMy wife’s roof had only a single layer of shingles. If I had more than a single layer I would scrape them off as it would potentially overload your roof trusses or rafters.
We placed 2×4 flat on top of the shingles running the long direction of the roof and 24 inches on center. Allowable spacing will vary due to snow load where the building is and load capacity of the steel. You are going to hear (actually read) me tell you I would do it differently soon. We used 40d threaded hardened nails to attach the nailers – with two nails through the nailer into the top chord of each truss. The nail length (five inches) is enough to get into the trusses comfortably with the threads helping to resist wind uplift issues.

A1V radiant reflective barrier was placed draped loosely over the nailers and the steel installed with 1-1/2” long powder coated diaphragm screws.

Here is what I would do differently next time. I’d run a 1×4 nailer up the roof on top of each roof truss., then the 2×4 nailers. This would allow for free airflow up the roof for eave to vented ridge.

For trims, use an eave trim at the low edge along the sidewalls. Install on top of 2×4 nailer at edge of overhang leaving the vertical about an inch out from the fascia. Place one inch thick venting material between the vertical leg of the eave trim and the fascia to keep insects out. Standard Rake trim and Ridge Cap can be used, with vented closure strips beneath the ridge cap.

It’s been about eight years since we reroofed my wife’s house and garage with steel and it still looks brand new.

Lightning and Steel Covered Pole Buildings

Lightening and Steel Covered Pole Barns

From a www.kmbz.com story of March 8, 2018 by Jim Cunningham:

“Each year more than 100 people are killed by lightning in the U.S., according to the National Weather Service. Another 300 people are injured in the electrical strikes. 

Severe Weather Awareness Week is March 4-10. 

In most cases victims of lightning strikes are outdoors, but some structures do not provide adequate protection from lightning, said Al Pietrycha, NWS Meteorologist.

“Several years ago in my pole barn, only 200 feet from my house, this storm came up and I wanted to watch it, thinking I’m okay, I’m okay,” Pietrycha said. “Lightning struck the barn and I got knocked off my feet in the compression wave, and since then I’ve lost some hearing.”

Pietrycha says he should have listened to his own advice that day to take lightning safety more seriously.

Lightning can strike up to 10 miles from a thunderstorm. Vehicles and enclosed buildings offer the best protection. Pietrycha says people should wait at least 30 minutes after a storm has passed before going back outdoors.”

Here is what Bryan Arlington, PE of Star Building Systems has to say about metal roofs and lightning:

“It has been observed that installing a metal roof makes building owners think more about lightning and the dangers of lightning strikes. There is a perception, or at least a suspicion, that a metal roof will increase the likelihood of lightning striking the building. After all, metal is highly conductive, just like the materials used in lightning rods that are used to attract lightning strikes, so doesn’t it stand to reason that the metal roof will attract lightning, too?

The short answer is, no, a metal roof will not make lightning more likely to strike, but it may make a lightning strike less dangerous if it occurs. That’s right, less dangerous, not more.

The Metal Construction Association, in its Technical Bulletin MCA13a, breaks the issue down into two issues: probability of a lightning strike at any particular location, and the consequences of that strike.

Lightning has been studied for hundreds of years, and there is good general information about how it works, but many of the details of how it forms and where it strikes are still unknown. That lack of knowledge means that its behavior remains unpredictable.

Lightning is a rapid discharge of atmospheric static electricity. There are three major types of lightning strike: Intra Cloud (IC), discharges inside a single cloud, from a highly-charged area of the cloud to a less-charged portion; Cloud-to-Cloud (CC) discharges from a highly-charged cloud to a less-charged cloud; and Cloud-to-Ground (CG) discharges from a highly-charged cloud to the earth. CG is the type that is best understood, and the type we are most concerned with in terms of dangers to life and property.

The exact location where lightning discharges appears to be governed by geography and topography, as well as the movements of the storm.  When lightning is ready to discharge, it will, whether there is a metal roof handy or not. It is faulty logic to assume that a metal roof attracts lightning strikes similarly to a lightning rod, because lightning rods are not made to “attract” lightning. Rather, they are made to channel lightning safely to the ground if it happens to strike the location of the building.”

Come back tomorrow for the conclusion on lightning and metal covered pole buildings.

Remodel: Gutters and Snow Brakes

One of my Facebook friends, Scott, has recently been doing a house remodel on a home he purchased in Spokane, Washington. He has been good about posting progress photos, until today when he posted a non-progress photo.

The casual article skimmer will notice the photo and perhaps think this “gutter on the ground” issue must be due to installer error. Having been down this very same road, I can reasonably assure you, kind reader, to this being a problem of the roof itself.

When I first built my small garage at our Newman Lake, Washington home, I had gutters put on it. The gutter installer would only guarantee his work, if we had a snow retention system installed on our roof.

You can bone up on snow retention systems herehttps://www.hansenpolebuildings.com/2017/01/snow-sliding-off-roof/

Because there has been an inordinate amount of snow in various areas of the United States the past few years, I will probably begin to sound like a nag when I repeatedly discuss not only proper snow load design, but also proper design for keeping the snow where it belongs – on the roof, not falling off and injuring anyone.

In a recent Spokesman-Review article (read the full article here: https://www.spokesman.com/stories/2017/feb/05/snow-falls-off-roof-of-selkirk-lodge-causing-minor/) snow sliding off from a metal roofed lodge injured several and resulted in at least one ambulance ride. With the proper snow retention system in place, the slide off event would probably never have occurred.

Why aren’t snow retention systems required? Especially on metal roofs?

The first reason is always down to “cost”. People selling and constructed buildings have an inane fear of trying to discuss added investment, which adds to the price.

If it helps to protect an innocent person from being injured or worse killed – it was a cheap investment. As a consumer, just explain the benefit to me and I am a believer.

The second reason is because it is not a requirement of the Building Codes. I am certainly no fan of government intervention however the Codes at least form a minimum framework from which buildings can be designed and built so as to prevent loss of life or injury. Hopefully this small portion of the Codes will be addressed in the future.

Meanwhile, it is up to me to inform – an informed new building owner is the happiest one, as they ended up getting what truly works best for them over the long run.

Metal Building Insulation in Pole Building Part II

If you didn’t read my yesterday’s blog – you may want to prior to reading today’s, which is the “rest of the story” on metal building insulation, commonly known as “MBI”.

My first experience installing MBI was not a fun one, in any sense of the word “fun”.

What no one warned us about were safety issues during installation. We should have been advised to wear protective gloves, a dust mask and goggles when working with insulation. Insulation is made of tiny fiberglass shards, which can cause serious irritation of the skin, eyes, nose and throat if you don’t take proper precautions. Instead, we spent several days with red eyes, itching skin and hacking up our lungs!

Now fiberglass itself is not some “magic” insulator, it is the dead air trapped in the uncompressed fiberglass which is doing the work. Smash the air out, and you lose R value. As far as an insulator, every time metal building insulation crosses a framing member, it is compressed to nearly nothing and loses its insulation value. People have this mistaken illusion “thicker must be better”.  Not true. Going to thicker products generally does not really add to the overall heat transfer resistance.

In years since, I’ve had clients tell me how a competitor proposed to insulate their new pole building with R-11 (3-1/2” thick) or even R-19 (6” thick) metal building insulation! First, I would hate to even imagine what the steel would look like, after trying to mash insulation this thick down and screw the metal through the insulation to the roof purlins. It would NOT be pretty. (read yesterday’s blog to see why).  Secondly, there is no way the fiberglass is going to come anywhere close to being able to fully expand between the roof purlins. Keep in mind the “product” does indeed have an R-11 capability (in the case of 3-1/2” thickness), when it is laid out in your driveway. As soon as it gets compressed, R values start to shrink. My educated opinion is a 3-1/2” thick product, in service in a pole building, is probably offering a true R value of between 2 and 4 – just slightly above nothing.

We (Hansen Pole Buildings) now partner with several lumber yard chains, providing pole building kit packages to their clients. Two summers ago I was visiting one of the lumber yard locations in Pennsylvania, in order to provide training to their staff. I went out into their warehouse to greet the store manager. Looking up at the roof of this pole building, I saw tattered MBI hanging down from between the roof purlins and hundreds of birds pecking at the fiberglass, to carry it away for nesting! Any hole in the vinyl at all, and a bird in the building, will result in exactly the same scenario being replayed – much to the chagrin of the poor pole building owner who now has no roof insulation, no condensation control vapor barrier under the roof steel of his building, and nothing but a mess.

In my over 30 years of experience, I can truthfully say I’ve never seen Metal Building insulation look to be a perfect “clean and neat” install product under roof steel.  Moreover, far too often I’ve visited older buildings where the inside view of this product “over time was enough to convince me it was not the optimal choice for pole buildings underneath steel.  Back up a few days to read other blogs where I discuss vapor barrier and reflective radiant barriers.  And stay tuned – for more on other insulation products!