In the first half of the 20th century roofs in missouri were built with wood shingles over planks spaced about 1 apart.
Old roof decking.
In older houses decking is typically made of lumber place perpendicular to rafters trusses.
Plank sheathing usually 1 6 or 1 8 was used as a roof deck before plywood.
We knew that this old house had significant gaps in the wood p.
The new plywood thickness should be.
Until the 1940s exterior grade plywood was not available.
In the 1950s plywood sheathing and particleboard became common and today most standard construction roofs use either half inch plywood or particleboard s big brother oriented strand board osb.
If you remove it all then reinstall you can have cracking and popping of the drywall ceiling.
As long as the new plywood itself can span the distance and carry the roof wind seismic and snow loads for your region adding new ply over old is just fine.
Roof decks on homes built before 1970 are often 1 8 fir pre plywood shiplap.
If there is a leak in the roof plumbing or windows the mold will reappear if the water is.
Prevent future mold growth.
These decks rarely had roof insulation installed on them since energy was relatively cheap so typical construction might have called for a layer of rosin treated paper followed by two layers of bitumen impregnated roofing felt nailed followed by three more layers of 15 asphalt or pitch impregnated organic roofing felt mopped together.
Plywooding over old roof deck one thing to consider when stripping off the old plywood is to remove and replace as you go.
That will save you as much as 1 000 and a fair bit of mess but it means the roofer can t inspect and repair the decking and flashing underneath.
It is important for us to point this out because here in maine many historic homes are maintained for both residential and business uses.
Older homes may very well have a different type of roof decking than newer structures.
To prevent future mold growth remove the source of moisture causing it.
Old houses with asphalt shingles usually had either tongue and groove boards or straight sided boards abutting.