leaking metal roof

[ng8264723]

I have a metal roof on my shop that leaks. It only leaks from one spot but I can't seam to find it. I went to the top of the roof and silconed all the screws close to where the leak was and it still leaks. Any ideas? Do they make a silver tar like paint I could paint over the area with? The roof is the typical corrugated stells with screws into the purlins

 

[RivennHewn]

Try replacing the gasketed screws. The rubber gaskets fail.

 

[crazytrain]

http://www.lowes.com/pd_12035-29-51...L=?Ns=p_product_qty_sales_dollar|1&facetInfo=

 

[Justanoldguy]

Pic of faulty area?

 

[Stinger]

Typically the water will run down the inside of the roof a long ways before actually dripping to the floor. This means the leak is often a long ways from where the drip is.

 

[camarotoolman]

Put a blue tarp on it and forget it. lol

 

[Tim The Tool Man]

Mine leaked badly when I bought my house. The building was (is) ugly so because I didn't care about appearance so I ended up slopping tar on many of the nails (no screws here!). That didn't 100% solve my issue so I carefully tore off my ridge cap and applied 8" wide window seal tape over the peak. Then I splurged and screwed the ridge cap back on. That did the trick.

Of course none of that matters anymore as I recently re-sheeted the roof and replaced all the nails with screws and butyl (sp) caulk. No leaks now...

 

[speadphreak]

Seal the screws on the sheet above the leak all the way to peak.

 

[oldgoaly]

white elastnomeric roof coating, We chased a leak(S) on old machine shed that I turned into my foundry and Blacksmith shop. Living on a farm we have done about 1/2 the buildings, 1st brushed it on now have a pump sprayer. These are older buildings that I've put about 3000 screws in and my boy has put in over a 1000 replacing old nails.

 

[Justanoldguy]

So I guess the OP isn't coming back with any pics..

Moving on...

 

[ng8264723]

Well I could snap some pics but I don't think that would help. The roof is galvanized and has the scrws with the little gaskets on them. The leak is at the top purlin. So I guess I could take the ridge cap off and peak under it. What a pain. The ridge cap doesn't have silicone under it. There is a pretty good overlap so I don't think it's needed. I'm definately missing something. I'm just not sure what. I thought a silver type of rubberized roofing paint would do the trick if there was ometing like that available. Since the leak is only a few feet from the top I would probably only have to do a 8 by 2 foot section

 

[aardquark]

Maybe wind is blowing the rain up the roof under the ridge cap. Is there anything under there to prevent it? Z-flashing? Ridge vent? I have even had some success by putting strips of redwood under the ridge cap of a 5-V style roof.

 

[Tim The Tool Man]

Maybe wind is blowing the rain up the roof under the ridge cap. Is there anything under there to prevent it?

That was my issue. The water blew up under the cap and ran down the inside of the roof a couple feet. There was a foam material that was supposed to prevent that under the flaps of the ridge cap but it was so old and dry rotted that it was useless. As I stated earlier I removed the cap and applied flexible flashing at the joint where the roof sheathing meets.

This stuff: http://www.servicemagic.com/article.show.Flexible-Flashings.13630.html

 

[Justanoldguy]

Well I could snap some pics but I don't think that would help. The roof is galvanized and has the screws with the little gaskets on them.

The reason I ask is I have seen dozen of roofs in the USA that have the screws in the valley of the iron. eg the bottom of the river .. lol
Here in NZ that is a definite no no.
Always put on the top of the ridge.
eg

 

[dadsEH]

I chased a leak at the top of my 30 year old roof for ages! closest of inspection could not find anything. The water would appear dripping off the first purlin from the top of the roof. Finally I took off the ridge cap and found that over years of expansion/contraction the sharp edge of the cap had worn a small split in the corrugated panel. I put a small sheet of steel between the cap and corrugation and fixed it.

Check for dark line at the edge of the cap where it sits on the corrugations.

 

[dladcock]

I bought my home with shop in 1986. The shop building has a tin roof. It leaked bad from day one. I used spray undercoating on all the nail heads after driving them back down and spray undercoating on suspect seams as well. The leaking stopped, then about five years later we cool sealed the top. Hasn't leaked since the undercoating and has out lasted my intentions for the building 15 years. Now I wonder if that bed liner in a can would be better than undercoating?

 

[bad311]

Try replacing the gasketed screws. The rubber gaskets fail.

This- replace the screws...