# Odd roofing issue



## RandyLeeTurner (Oct 18, 2012)

Hey guys,
I'm the Facilities Manager at a church and school in TX, and recently we've had a leak emerge in the sanctuary. I've attached pictures of the area of the asphalt shingle roof where it's leaking. Essentially, there is about a foot diameter area where the shingles are raised above the subsurface. I don't know why this is happening, or at which actual shingle the leak is occurring... What is my best bet to fix it?

Thanks!
Randy Turner


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## Grumpy (Oct 29, 2008)

This very much appears like a substrate issue. Normally when I see this problem one of three things has happened. 

1) IF it is OSB, some water got beneath the roof caused the OSB to swell and that's what you are seeing. 

2) If it's CDX a 1/8" gap was not left on all sides of the plywood allowing for proper expansion and contraction. 

3) Or Fasteners were not installed in the proper quantity or in the proper locations, the board has moved over time and pulled out the fasteners (this is probably most likely). 


I'm also assuming this is a traditional "cold deck" design for shingle roofs. I mention this because alot of churches in my area are warm deck designs and have no ventilation. 


The fix is simple but time consuming. Take up the shingles in the affected area. Replace or fix the wood substrate as necessary, reinstall underlayments and shingles. Normally when we do these kinds of repairs we resecure with screws instead of nails. Also when we begin taking up shingles we can often follow the water trail allowing us to exactly determine exactly where the water may be entering.


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