Barn's metal roof leaks/ drips ...

tommu56 · Sep 10, 2010

the builder that built my garage he put a layer of tyvek on top the purlins under the roof to stop the condensation.

this work great and was cheap (he threw it in when i asked about stopping the condensation.

tom

Oliver1655 · Sep 10, 2010

- It sound like the wind is blowing the rain up under the ridge cap. There are three ways to address this problem. Two of them, wider cap and rubber strips have already been mentioned. A third option is a vented weather strip. These strips have sections of "horse hair" similar to scouring pads inbedded in them. The sections allow air to flow while helping to keep rain and snow out. I have used them and have never had a complaint.
- In regards to screw placement, with the neoprene washer screws, it is recommended to place them on the flat portion of the sheets. This provides a tight connection between the metal and the wood/steel purlins/rafters. This accomplishes two things. 1 - Steady pressure on the washers, 2 - Decreased the metal flexing which decreases metal fatigue. (Real important as the thickness of the sheets have decreased over the years.) Place one close to the lap on the top sheet and then one close to each small raised ridge. Placing a screw close to the ridge that is being lapped is NOT recommended as it may pull the bottom sheet away from the top sheet.
- The use of the caulking tape between the sheet laps will keep the wind from blowing rain underneath and from peeling the edge up in most cases. (If the wind is strong enough, nothing will hold.) Lap/Stitch screws (the shanks are wider to cause the metal to mushroom as the screw goes in to give it more to bite to,) are used down the center of the lap ridge and only go through the two sheets of metal.
- As previously mentioned, lead capped nails are pretty well a thing of the past.

Hope this helps.

anojones · Sep 11, 2010

My ridge vent was leaking, mostly when the snow would drift under the vent. I have a sheetrock/linsulated shop/studio in my pole barn and needed to get it stopped. I used a product that seals out the moisture like mentioned above- I haven't been able to find it again since but here's a link- easy to install, adheres to the metal and then the vent is screwed down right through it.

North Star Metals-Manufacturers of Metal Roofing&Siding, Ohio

Chuck52 · Sep 11, 2010

beppington said:
Chuck ... Yeah, there is a big gap, 3/4" high & about 8" long each, according to the dimensions I see ... So, your foam plastic seals actually sealed all those gaps?? I guess air just exists thru vents you have in your gable ends?

Bepp,

That's about right. I think I've got an extra piece of the foam around somewhere. As I recall, it has a sticky side you expose, and then stick it on....it may have a thin piece that fits over the ridges. I think it is not air-tight. It just stops the blowing rain. My barn has an open side so ventillation is no problem, but even if the foam were pretty air tight you'd have the ends. Seems to me, if you can reach the peak, you could get some of the roled up foam insulation and slide that in the gaps.

Chuck

/pine · Sep 11, 2010

...the builder that built my garage he put a layer of tyvek on top the purlins under the roof to stop the condensation...

so where does the moisture go?

tommu56 · Sep 11, 2010

/pine said:
so where does the moisture go?

My guess there is enough trapped dry air above it to insulate some.
I don't get any drips or other moisture.
no windows 1 walk through door 1 10x8' OHD
Concrete slab with vapor barrier under it.

tom

clemsonfor · Sep 11, 2010

runs down the tyvec on the upper side and drips down walls. I also was thinking that it created insulating air space

300UGUY · Sep 11, 2010

I just put one on a neighbor's garage, it was Menards product. Probably about the same as the HD stuff. The package we had had a foam thingy than was made to go under the ridge cap. It lets air in or out, but keeps insects, birds and snow or wind driven rain out. That is all you seem to be missing imho.

clemsonfor · Sep 13, 2010

i looked at my shed yesterday and saw that my "feet were not all on the bottom, its not a big deal to me as its an open sided woodshed with a leanto sloped roof.

That said i have no leaks under it no water under the underside of the tin short of 3 "s from the front where it runs off from the top side in drips. I also have no leaky screws or wet marks in the wood where the screws penetrate.

I even used , 2nd hand tin from a coworkers shed i helped him dissasemble, some are thicker as they were the top to the shed and some were thinner as they were originally the sides of the shed, but all has the same shape the OP used. Mine is clearly not assembled right but it also dont leak on the underside and yes i have been under it in a rain looking for leakes, as i did not use the original screw holes so i used that black roof patch stuff and gooped it in the screw holes i did not use.