# Replace whole roof or half roof??



## USP45 (Dec 14, 2007)

the new roofer is 100% correct. That indicates no air flow through the joists causing the roof to heat up and bake the shingles and causing condensation. He is probably going to install some pannels made of cardboard or stryophome to keep the insulation off the plywood A+1! Thats what needs to be done, get the insulation off the plywood and allow an open channel all the way to the soffits. as far as the rest of the roof. 25 year shingles-10 years = 15 good years left on them. There is nothing wrong, but not usually the way a pro would do it, but re roofing over a layer of shingles is OK if the underlying shingles are laying flat. If they have curled any then they should had been removed as this will keep the new from setting flat and sealing themselves down. Just look and see if they seem to sit flat, and they are hard to pull up then you are probably OK on the back. If you can easily pull the bottom edge of a shingle up with no effort, then replace them. Might I add that i reccomend a ridge vent as opposed to a gable end vent due to the fact that hot air always rises to the ridge, so thats the best place to let the heat out.


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## jdsong (Mar 15, 2008)

USP45 said:


> the new roofer is 100% correct. That indicates no air flow through the joists causing the roof to heat up and bake the shingles and causing condensation. He is probably going to install some pannels made of cardboard or stryophome to keep the insulation off the plywood A+1! Thats what needs to be done, get the insulation off the plywood and allow an open channel all the way to the soffits. as far as the rest of the roof. 25 year shingles-10 years = 15 good years left on them. There is nothing wrong, but not usually the way a pro would do it, but re roofing over a layer of shingles is OK if the underlying shingles are laying flat. If they have curled any then they should had been removed as this will keep the new from setting flat and sealing themselves down. Just look and see if they seem to sit flat, and they are hard to pull up then you are probably OK on the back. If you can easily pull the bottom edge of a shingle up with no effort, then replace them. Might I add that i reccomend a ridge vent as opposed to a gable end vent due to the fact that hot air always rises to the ridge, so thats the best place to let the heat out.


 
The only thing it is a 15 year roof that was put on 10 years ago on top of a old 15 year roof. I do not know how many more we will get out of the back roof anyway.. I still think the roof is leaking somewhere in addition to poor circulation issues. I could be wrong but the back on the house gets the afternoon sun most of the day so I would think that would be were the poor circulation would be more so then front. After that nasty wind and rain storm the shingles started coming off so I am sure stong winds had so issue here also!! I am glad we had a few shingles blow off as otherwise we would have never called a roofer out and never saw the mold and wet plywood issue.. We did notice the roof getting wavey in the front of the house after the storm but not before so not sure if missing shingles just made us look more at the roof or if if started after the wind and rain storms.. Anyway thanks for the info!!


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## USP45 (Dec 14, 2007)

Glad to help


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## skymaster (Jun 6, 2007)

IMHO if this were mine; strip the whole thing,dump insulation,replace any sheathing damage, new roof entirely. If you dont you will regret it much sooner than you think and it wil cost way way more than just doing whole thing now


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## Ed the Roofer (Jan 27, 2007)

More than likely, due to the insulation being so tightly packed in each of the rafter bays, the wet insulation and plywood you discovered, (through the proper diligence of your roofer knowing to look for it), and also due to not having continuous intake and exhaust air flow to ventilate the spaces, the entire moisture problem is insulation and ventilation related.

The reroof 10 years ago did not create this situation.

The plywood on any side that the insulation is completely packed too tight in must be removed, even if only one side is showing the effects now, the other one will down the road.

The wet and moldy insulation should be removed and replaced with new. On top of the insulation, you need to have insulation baffle vent chutes installed. 

At the bottom eave edge of the roof, either the entire soffit needs continuous length strip intake ventilation, or install Smart Vent, by DCI Products, to provide fresh air intake under the first courses of shingles.

In the top of the roof, it will need a full length of ridge vent, and I recommend the Shingle Vent II made by the Air Vent Corp.

Also, you should "STRONGLY" consider putting on at least a 30 year architectural style shingle instead of a cheap thin 25 year shingle.

One final note, gable vents will not work at all in your roof design, because of the enclosed rafter bays. It is not an open attic area, so that information previously provided was incorrect.

Ed


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## tinner666 (Mar 14, 2005)

Good call Ed.


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