galvanized barn roof is leaking

I have a 40+ years old corrugated, galvanized barn roof. It does not have rust, large holes or missing sheets. In fact it has held up remarkably well. I had, some years ago, treated every nail with a black tarry sealant (I bought at Home Depot and commonly used) due to a few minor leaks. After 4-5yrs the tarry substance developed hairline fractures and the roof had 2-3 small leaks. I was told to remove all the now dried and cracked tarry substance and use new screws with washers. I followed the recommendation and now have with this years rain, multiple leaks in the barn roof. I used the tarry substance because I was told to seal the entire roof with a paint like seal would be too expensive. However, I now have spent in labor and materials far more than the projected cost of the paint-like sealant. What do you recommend as a diy but good/solid solution to a still sound roof that only leaks at screw/attachment areas? Thank you for your help.		Marisabel Gouverneur 11/14/2017	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/22671/find/
Are the leaks through the screw locations or in other spots? Need to know where it is coming from to recommend a "fix" in this case.		Eric Novotny An informed customer is the Best Customer! 11/14/2017	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/22672/find/
I agree with Eric. the leaks may not be coming from the fastners; particularly if the fastners are on the high part of the rib. often times leaks are coming from a point higher on the roof, like the ridge, penetrations or other flashings. it could even be due to condensation dripping. can you post some pictures of the exterior and interior. Maybe we can offer some other ideas.		Dick Bus 11/14/2017	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/22673/find/
Gentlemen, Thank you Mr. Novotny and Mr. Bus for responding, Unfortunately the text which I submitted did not clearly state that the leaks were entering at the fastener sites. Having experiences of leaks in various countries working in buildings for international health issues, I know that where you see water/wet is not necessarily the point of entry. The leaks/ point of entry of water in my barn were all at fastener sites. In desperation I treated every fastener with a roof sealant and the leaking stopped completely. It appears that in the recommendation, I had received, to remove the previous sealant and replace the fasteners there was no mention of using any back up sealant. I must imagine that since the new fasteners did not complete seal the old nail holes leaking occurred. We have had significant rains already this season and there has been no leaking. Thank you again your willingness to assist me. Happy New Year		Guest User 12/30/2017	Share Or copy this URL: https://www.metalroofing.com/spirit/comment/22674/find/

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