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Replace whole roof or half roof??

13K views 6 replies 5 participants last post by  tinner666 
#1 ·
We have had very bad wind and rain storms here last week and they took about 10 shingles off our roof front and back (mostly front of house) When we had a roofer look up on the roof he told us the front was soft and beveled wavy looking. He asked if our attic was finished and I told him yes and please have a look in the eves as years ago someone not sure who told us that the people before us that finished the attic over insulated it. He looked in the eves and removed the insulation in the area where the roof looked the worse and white mold and wet rotten plywood was on the front of the house. The rafters are stained and insulation wet. He said we need new plywood and roof in the front of house but the back seemed ok but not 100% as that side is also insulated the same way but when he took out one sheet of insulation that plywood seemed fine but really can't tell by one piece removed. He suggested replace front of house with 25 year shingle and new playwood and he would take out all the insulation in the ceiling part of the attic and put in something else but forget what it was he said. Or he could replace the whole roof with 25 front and back but only buy new plywood for the front as he did not feel the back really needed it. The issue is 10 years ago we had wind damage and had a roofer come out and put another 15 year roof over the old so now both layers will have to come off.
Was this the wrong thing to do 10 years ago and could this contribute to leaking issues and adding the issue that the attic was over insulated 20 years ago be adding to all this problem?? Will try to submit to homeowners but have no idea what they will cover of this.. Should we do half or whole roof at this point????
 
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#2 ·
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.
 
#3 ·
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!!
 
#6 ·
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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