# Sealing closed cut valleys



## tranman (Oct 2, 2008)

Hello, I am just about finished roofing my house. I used laminated 30 year shingles and membrane in the valleys. I've used Henry roofing cement around the flashings and roof penetrations. However, I was wondering if it would be better to use a 100% silicon caulk on the cut edge of the shingles in the valley, or continue to use the black roofing cement. Opinions?


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## tranman (Oct 2, 2008)

*Also*

Because of the heat, the majority of the shingles have sealed. Should I try to pry them up, or just leave the whole thing alone? I have not applied any cement or sealant to the valley cut.


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## johnk (May 1, 2007)

if its all sealed,leave it alone.


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## Slyfox (Jun 13, 2008)

Instead of lifting the shingles individually, simply lift them several at a time 'lifting gently from the cut edge' and place your 'roof cement' under far enough so it's not visible,
never use silicon under or in between shingles, it's not compatible and will never fully bond to the shingles and will prevent the shingles from re-bonding to each other.

In my area 'Youngstown, Ohio' we seldom run sealant down the closed cut valleys unless the slope of the roof is leass than a 4/12,
so depending on where your located and how teep the roof is, you may not need the sealant if you properly installed the valley.


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## OldNBroken (Jun 11, 2008)

johnk said:


> if its all sealed,leave it alone.


Yeah, what the canuck said.:thumbup:


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## tinner666 (Mar 14, 2005)

Yeah, sounds like it's too late to fix now.


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## tranman (Oct 2, 2008)

Thanks for the help. I will try to spot seal with roofing cement where I can. We had a pretty good rainstorm the other day and I did not notice any obvious leaks.


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## Ed the Roofer (Jan 27, 2007)

tranman said:


> Thanks for the help. I will try to spot seal with roofing cement where I can. We had a pretty good rainstorm the other day and I did not notice any obvious leaks.


That really shouldn't be necessarry to do.

Ed


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