Have you thought about doing this yourself? It's not easy but it is certainly do-able. Find some strong 18 yr old guys to help you and lots of patience. We ripped up about 600 sf last summer and it was definitely worth doing ourselves. First carefully remove your shoe and base moldings so you can put them back down when you are finished. That's another expense you won't have. Replacing those will add up! You'll need: a trailer or someplace to dump what you've ripped up a bucket for the nails you pull up crowbars and other assorted pull bars, nail extractors hammers several strong college age guys If you need to put down red rosin paper or felt paper, you can very easily do that yourself too. We had our flooring installer put in the new plywood underlayment, (we laid the felt paper)but he didn't charge us as much because he had a nice clean place to start. It was like $1.00 sf.

Thank you for your resoponses. Yes, something appears amis. This roofer got good ratings in Washington Checkbook too! Replacing plywood is something a roofer should be able to do. Its difficult to examine the roof from the inside. Its a Cape Cod style house, and the majority of the wood was replaced on the portion of the roof that has on the inside only a stud cavity and then drywall for the upstairs rooms. There is insulation in the stud cavity and I think it DOES NOT have a vapor barrier, and I think that is why the wood degraded over the years. I may be able to go behind the knee wall upstairs and view from the inside one of the pieces of plywood that is lifting. I do not think this is a moisture issue, because I noticed it within days of the roof being installed. Also, about 12 years ago the roof was replaced (by the previous owner) and some plywood sheets were replaced. Those replaced sheets are still in great shape and are not lifting a bit. --Nate

The thickness of the sheathing depends on the spacing of the rafters and you didn't tell us that so I would recommend at least 5/8" CDX plywood or Oriented Strand Board. Asphalt saturated felt (building paper) underlayment once weighed 15 lb per 100 s.f. but it is now much lighter and therefore called No. 15. To match the original standard it is necessary to use No. 30 building paper. The shingles may have lasted 25 years but obviously they did not protect the sheathing so the design was inadequate possibly because of a low slope. If you want the roofing and sheathing to last another 25 years install an underlayment of self-adhering Ice & Water Shield from Grace without substitution.

That is a problem all of us experience. We know what we mean, but often leave out seemingly small details we do not realize are important. In this case, the missing info was so important, leaving it out means all the info given is not applicable. Using the new info, it is up to the insurance company and the policy as far as replacement. If the policy states replace in kind(using what was damaged) and that material is acceptable under local codes, then replacement of the original type material should be done. That means the boards will be replaced as originally installed, regardless of butt spacing or T&G type. However, if there is no specific wording, repairs are generally done according to local building codes, with the actual selection of materials done by cost. Another difference is material thickness. As a rule, solid wood boards were 3/4" thick. Plywood is not an actual 3/4"(or 1/2", 5/8", etc.) thick. And OSB can be thinner or thicker than the nominal thickness. That means mixing types of materials is not a good practice. Testing has proven, using dimensional(solid) wood boards installed on the oblique to the support framing for roof sheathing or subfloor construction is the most stable and strongest material commonly used. The down side is that method is also the most expensive and labor intensive (meaning more expensive) method. Plywood was less expensive to buy and install. And OSB was cheaper than plywood. Then there are climate conditions. As reported in the link provided by worthy, OSB is subject to edge swelling, which can only get worse with age and exposure to moisture. There are water proof versions of OSB, they are about half to 2/3 heavier than conventional types and MUCH more expensive. To the point is is not worth using, since other less expensive materials are available. I've seen tests where the waterproof variety sat under water for 6 months and was completely undamaged. It was, sadly, too heavy and expensive to use as subfloor material and would be way too heavy for roof sheathing. Plywood can delaminate and solid wood swell when exposed to moisture. Once that moisture is gone, both types can return to near original dimensions and strength. Even delaminated plywood can have near new strength. All the types of sheathing will be eventually weakened by continual exposure to water/moisture. That is why techniques to prevent moisture/water intrusion are as important as the type of material chosen.