Barn Roof repair...looking for some tips

chado613 · May 17, 2016

I have a 350-400 sq ft steel roof on an old barn that has numerous leaks. I suspect the leaks are coming from the washers around the nails have degraded.

Unfortunately it is very hard to identify where exactly the leaks are coming from, seems like its different every rain storm. Also I am not a huge fan of climbing up there.

My plan of attack is to go up on the roof with black jack ultra white (BLACK JACK White Ultra Roof 1 18.9 L White Roof Coating | Lowe's Canada) , some leak seal, some caulking, some new roofing screws and of course a safety harness

Some of the worst areas, I intend to cover all the screws with a dob of blackjack, replace any screws that are obviously messed up and caulk and leak seal as needed.

Any other tips from anyone out there??

zzvyb6 · May 17, 2016

Can you work with a partner who is inside watching while you run a water hose or bucket over the fasteners and seams ? Otherwise its gonna be a long Summer.

Zerk · May 17, 2016

Wait for a warm sunny day, after the snow has slid off, and go up there. That way the snow cushions your fall.

The thing to do would probably be to replace the nails with screws. But that would talk along time. A metal roof really shouldn't need caulking, unless you have something on it or through it, and then, caulking is supposed to be secondary, but often is primary.

I learned from a roofer to put the caulking under the metal, so the sun doesn't degrade it, when putting new metal on.

I don't like goin up on a metal roof with a 5 or more pitch.

You can screw a board along the bottom, to rest your feet against, for stability. Maybe bring bucket around.

What are you going to tie off to? That is the tough part. Don't tie off to the wifes car, on the other side, unless the keys are in your pocket.

EddieWalker · May 18, 2016

I think you are wasting your time with the roof coating. More then likely, the leaks are caused by the fasteners holding the roof in place. While it could be the gaskets, it is also very likely that over time, movement in the roof has loosened the nails and allowed the roof to move during a storm. If you do not stop this movement, nothing will seal it.

You need to remove the nails and install screws. This is a very slow, tedious task. It's not very expensive, but the learning curve to get the nails out and install the screws quickly is going to take some time.

hosspuller · May 18, 2016

I just replaced a metal roof that was nailed. The best technique was to use a pry bar and a claw hammer. Use the hammer to tap the pry bar under the nail. Then place the hammer head flat between the roof metal and the pry bar. This saved the roof from damage and provides a good angle to remove the nail.

Definitely replace with screws.

xring · May 18, 2016

I was once involved in building a barn for a small private school where I was the only one present that had ever actually built one. The other volunteers vetoed my premise that the nails go on the top of the corrugation not in the valley "because it was too hard to nail on the top and they would hurt their fingers, besides the gasket will seal the hole". Of course it leaked immediately they couldn't pull the nails because they were in the valley. They put some roof cement on the nails but that lasted a short time then they poured some coating on it & that helped some but looked terrible. Getting the nails out of the ridge of corrugated steel is easier but is still a chore unless you have that wood that matches the corrugation under the metal may be made of foam now. If you don't you can make a support board from that same wavy board and another board glued to it this will give you something to push on with the hammer when pulling the nails and wont bend the steel. Or you could use a piece of the steel to mark a 2 x and cut it with a saber saw. Your roof sure looks steep to me. Be careful.

Zerk · May 18, 2016

xring said:
I was once involved in building a barn for a small private school where I was the only one present that had ever actually built one. The other volunteers vetoed my premise that the nails go on the top of the corrugation not in the valley .

The nails or screw do go in the valley, or flat spot, not on the ridges. Maybe I am not understanding you. Did you want to put them through the 1" or whatever ridge? That is the wrong way to do it.

chado613 · May 19, 2016

I was wondering hoe effective the roof coating would be. My thinking is that it would have been faster to put a blob over the existing screws than to replace them all. I also figured it wold be more of a pain if and when I ever had to take the screws out.....I should have already gone up there and done a better inspection...for those interested I will provide a more detailed report after this weekend

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Thanks all for your input so far

EddieWalker · May 19, 2016

Zerk said:
The nails or screw do go in the valley, or flat spot, not on the ridges. Maybe I am not understanding you. Did you want to put them through the 1" or whatever ridge? That is the wrong way to do it.

Oddly, different metal roofing manufacturers will say to do it each way. The advantage to doing it on top of the ridges is it's out of the valley and less likely to leak. Disadvantage is that it will allow the metal to move more then when it's attached through the valley. Biggest advantage to securing the metal through the flat valley is that it's more secure as it's direct metal roof to purlin contact. If attached properly, the rubber washer will never have any problems keeping water out. When there are leaks from screws through the valley, it's always because the screw was over tightened and the rubber washer breaks or becomes dis formed.

Bigkrank · May 19, 2016

Zerk said:
The nails or screw do go in the valley, or flat spot, not on the ridges. Maybe I am not understanding you. Did you want to put them through the 1" or whatever ridge? That is the wrong way to do it.

Morton has about 250,000 buildings that say otherwise. Depends on how panels are designed and thickness, etc. I have resided old wood barns and built sheds with cheaper siding that you had and were recommended to screw on the flat part. Morton panels, not so much, ridge is higher and stronger with thicker gauge steel.

On a side note, I have three Morton buildings. On one 6 years old had a leak at one screw on the ridge. Called salesman who used to be a crew worker. He stops out, say worst thing you can do is put a blob of caulk on. He replaced it for free. Said in 28 years with company has yet to charge a customer for a roof leak.