Barn's metal roof leaks/ drips ...

[beppington]

I have a 28'x22' barn/ garage with a metal roof I installed myself (metal from HD) ... & it leaks/ drips only when it's raining (i.e. not from sweating).

I used the twist-nails with the soft lead washers pre-attached to them. All nails are on the top of each metal sheet's "^" ridge (i.e. not down on the flat surface, which I have seen others do).

So far I haven't been able to figure out exactly where the drips come in, but I suspect maybe from the metal ridge cap overlap joints since the drips seem to occur mainly right down the center of the barn, under the ridge. When I installed the caps I overlapped them about 3"-4" if I remember correctly.

The barn has open trusses (no ceiling) so I can get up in there if I have to, although the ridge height is only about 4', so it's no fun

When I installed the metal roof pieces, I ran them up toward the peak to within about 2" of the peak, to allow for some air flow, but to still have enough for the ridge cap to sit on.

Does anybody have any insight/ ideas? I seem to remember reading where sometimes tar paper is put down under the metal first because the metal can sweat. I didn't know anything about that at the time, so didn't do it; just put the metal right down on my 2x4 runners.

I could replace the nails with screws if anybody thinks they're the problem. I could remove the cap & replace it, if needed, maybe more overlap between the cap pieces is needed?

This structure started out as a simple pole barn with a metal roof, & then evolved into an enclosed barn with a regular garage door on both the front & rear.

 

[Carl_NH]

Ive got a 24x36 barn 10/12 pitch metal roof and dont have leaks when it rains but when we get a Noreaster snow storm the snow blows in through the ridge in a nice line down the center of the upstairs floor.

The metal roof runs up 1.5" from the peak, and then the metal ridge cap is 6" coverage on each side so maybe 4" overlap of cap on the roof.

When I finish the upstairs I plan to get up in there an put the mesh ridge material to prevent the snow from coming in..

As far as fasteners, they used 2" screws with rubber heads on the ^ portion too, and no leaks are occuring there, the only thing on the lead is the expansion/contraction of the metal from a hot summer afternoon, then rain, this might allow some water in but you would see this under each nailed point..

I suspect its a combination of splash and the low pitch, and or a too narrow ridge cap? Maybe just install a wider cap over the existing cap?

 

[smstonypoint]

I suspect its a combination of splash and the low pitch, and or a too narrow ridge cap? Maybe just install a wider cap over the existing cap?

I think Carl is right, although it might be better to just replace the existing cap with a wider one. I've seen foam "gaskets" for use in sealing the spaces between corrugated roofing and the ridge cap. They might work if the OP's roofing is corrugated.

Steve

 

[MD3]

We installed a metal roof on our camp and had a lot of water drips. This was due to sweating. I remember buying Styrofoam like panels that we installed under the rafters and extended them beyond the walls to under the eaves. The panels were designed for that purpose and I think that you can find them where you bought your metal roofing. It took care of our problem.

 

[Car Doc]

I am certainly no authority on leaky roofs I have my share still and I gain a little every time I attempt further repairs. That said and this is jmho the tin nails with the rubber washers work better but that's me.

The fact they probably don't actually hold the tin any better than the lead washers they may just seal better? You may get away with just brushing on some snowcap or snowseal?

I may not be calling it right at this moment anyway its a rubbery white compound comes in qts and gallons hardware stores have it you brush it or roll it on and Ive used it a lot its great for valleys and flashings etc. Anyway brush it on your nails and see how it works it wont hurt anything fact it may solve a problem you may not even have yet. hth

 

[Redgoatea]

There was another leaky roof post a few weeks ago where someone mentioned that putting the fasteners in the ridges voids the warranty on the metal. Don't know how accurate that statement is though.

My dad and I just finished putting in a new metal roof on my moms shop. It's 50'x20' we used the screws with a metal washer on top of a rubber one that came with the metal. Not a single leak in it. As much of a pain as it is I'm thinking you may want a rubber washer but pulling those nails will damage the roof. Maybe just throw a dab of Blackjack on the leaky ones. ??

 

[tallyho8]

First, you can not use lead head nails with Home Depot corrugated metal unless you use the corrugated wood strips under the metal to keep it from bending because HD metal is only about 36 gauge and will flatten out before the lead is smashed in to seal the holes.

If you used Home Depot's r-panels they are also too light of a gauge to use lead head nails on the ridges.

In the old days they would use 24 gauge corrugated metal with the lead head nails and it was thick enough to smash the lead to seal the holes.

Only screws with rubber washers will work on HD metal properly.

By the way, most metal suppliers sell 29 gauge metal panels cheaper than Home Depot sells their lighter panels.

 

[clemsonfor]

First, you can not use lead head nails with Home Depot corrugated metal unless you use the corrugated wood strips under the metal to keep it from bending because HD metal is only about 36 gauge and will flatten out before the lead is smashed in to seal the holes.

If you used Home Depot's r-panels they are also too light of a gauge to use lead head nails on the ridges.

In the old days they would use 24 gauge corrugated metal with the lead head nails and it was thick enough to smash the lead to seal the holes.

Only screws with rubber washers will work on HD metal properly.

By the way, most metal suppliers sell 29 gauge metal panels cheaper than Home Depot sells their lighter panels.

I found this out and they are by far cheaper. You can get it for a little over $1.20 or something for the lightest gausge pannel/ft at metal roof suppliers and lowes is like $30 something a pannel or almost $3/ft for that green roof they sell in store. Lowes can order they said cheaper, but it still dont beat the roof guys everyday prices.

 

[beppington]

OK, I went to the HD website to find the exact name for what I installed, & sorry but (not that it prob matters) I had forgotten that I actually used "Fabral 36 in. x 8 ft. Shelterguard 29 Gauge Steel Panel Galvanized". It's the 3' wide metal, & I was actually able to get 16-foot lengths, so no joints. Here's a pic: (I had used the 2' wide ^^__^__^^_ metal on my little well pump house)

First, you can not use lead head nails with Home Depot corrugated metal unless you use the corrugated wood strips under the metal to keep it from bending because HD metal is only about 36 gauge and will flatten out before the lead is smashed in to seal the holes.

If you used Home Depot's r-panels they are also too light of a gauge to use lead head nails on the ridges.

In the old days they would use 24 gauge corrugated metal with the lead head nails and it was thick enough to smash the lead to seal the holes.

Only screws with rubber washers will work on HD metal properly.

I believe I could remove all of the lead-washered nails with vice grips & replace them with rubber-washered screws ... wouldn't be fun, but ... however, as I mentioned I'm pretty sure the leaks are at the ridge cap since the drips occur right down the center of the bldg under ridge line. There don't seem to be any other drips occurring further down the slopes anywhere.

Maybe I just need to, as said, get a wider ridge cap & attached it with the rubber-washered screws?

Edit: The metal that's leaking for me looks like the "Eagle Rib Panel" on this picture:

 

[randy41]

I think the space between the sheets at the ridge might be a bit wide. i agree with the wider ridge piece as at least the first step. or get under there when its raining and get a look see.