Tag Archives: squaring a pole barn roof

Steel Roofing Stair Stepping

I’m Truly Trying to Stop

As the everyday readers of this column know, I have been reviewing the pole building going up across the street from our home in South Dakota. If you have not been keeping up, run back a few episodes!

I’ve been away from SD for a couple of weeks, so have only been able to look at photos of the end results. I’ll keep this brief, so we can move on to other fascinating items in the world of pole buildings!

When I was first speaking with Leroy, I ask who they bought their steel roofing and siding from – it was a one location roll forming company which was not too distant from the building site. He had a complaint about their roof steel.

Leroy told me the steel on the first side of the roof they did ran perfect, the other side “stair stepped”, therefore the flying shear used by the steel company must somehow be getting out of square in the middle of the building! Builder was absolutely sure this must be the problem and they had encountered it on several recent buildings.

If this was a onetime event, I could see it being a problem of manufacturing, but when it happens multiple times and in the same fashion – I look for other reasons.

Steel roofing and siding panels are created by passing the end of a coil of flat steel through a machine which, by a series of dies, slowly bends the coil into the desired profile. As the finished product exits the die cribs, it is cut, while “on the run” to a fairly precise length, using what is known as a “flying shear”.

So why is Leroy experiencing the problem?

My best guess is the first side of the roof runs easily because they are squaring up this side of the roof, prior to the roofing application. On the other side, it is possible someone is assuming it is square, maybe just by plumbing the corner columns, instead of making sure the plane of the roof is square.

My last rant (at least for now), is on the application of wainscot panels. A sheet of 7/16
OSB was applied to the outside of the wall girts, then the wainscot and siding were applied over the top. The OSB was installed with a space of 31 inches between framing members (or 34-1/2 inches on center with 2×4 members), which is far beyond the ratings of the OSB to carry or withstand any sort of a significant load.

Almost anything which could hit the wainscot hard enough to dent it, is going to be crushing the high ribs of the steel – the OSB behind it is not going to keep the ribs from denting. If the idea is to protect the wainscot, I’m generally not buying into it, unless the protection is supposed to be from things on the inside of the building.

Instead of using a piece of steel wainscot trim between the wainscot panels and the siding above, the upper panels were merely lapped over the wainscot! Apparently the idea is this is supposed to seal tighter, however experience tells me these panels will not lay flat to begin with (they are exactly the same in profile, not swaged – to neatly interlock). With expansion and contraction, as well as the spacing of adjacent screws, there will be frequent gaps between the panels.

The question I want answered is – how was the builder able to get the steel to lay flat with the 7/16” jog at the lip of the OSB?

Ok – I’m done now. As much as I would love to be there and visually see for myself other challenges they had with this building, I believe it’s time to let it rest.

Day Three at Steve’s: Squaring a Roof

This week I am relating a recent day by day account of putting up a pole building for my oldest step-son’s father-in-law in Happy Valley, Tennessee.  Check back to Monday for the beginning of this string.

On to day two on the jobsite…another sunny day.  (Read that as “oppressively hot and humid”.) Jake picked up a towable manlift for placing the rest of the trusses. This turned out to be a true back saver.

While the rest of the trusses were lifted into place, I cut all of the roof purlins to length, using a permanent marker to put arrows for “crowns up” on each of them. As trusses were installed, the purlins got placed into each bay, to stabilize them. The man lift proved handy in getting purlins into place, as it made working 12 to 17 feet in the air, a snap.

Here is where we caused ourselves some challenges, in two respects. One – not all of the handy arrows directions were followed by those doing the installs, and the second – the purlins needed to be fit tight against the trusses, in the joist hangers.

The roof did get all framed up, however the next morning found the aerial crew having to spend a good portion of the morning taking joist hanger nails out of purlins and fitting them tight, as well as flipping over a few purlins so the crowns were the right direction. Because wood is flexible – and not absolutely 100% perfectly straight, just cutting purlins to length and installing them means they will fit snug on the first try.  What needs to be done is to use cable come-alongs from truss to truss to tighten up each bay, thus pushing the purlins tight into each joist hanger.  This is an important step in ensuring the building comes out “plumb” and “square”. Extra time spent for squaring a roof will save a mountain of headaches once application of roofing and siding materials ensues.

Once all was good and snug, we started to square up the right side of the roof. When squaring a roof, the best way to go at it is to focus on one half of the roof at a time. The overall roof lengths were absolutely perfect – the fascia and ridge were exactly the same length, and exactly what they should have been. Goes to show what pre-cutting all of the purlins to length and making sure they are tight against the trusses in each bay can do for a job!

We checked the diagonals…while holding our collective breath. They were exactly right on the money! Life was good. Fascia was straight and we were ready to run roof steel.

At 100 plus degrees, we did not get far – opting to wait it out until cooler temps the next morning. While admiring our work, we noticed a strange hump in the fascia on the opposite side of the building….uh oh – problem!

After investigating, the problem was found, but the solution took some thought.

Come back tomorrow for the answer.