My home from 1948 has an add-on attached off the kitchen. It is built on framed 2 by 6's. These are just laid right on top of an old porous cement slab that is part of the old patio. This room has water damage & some old vines have also grown thru the cracks. I have the flooring all up, the siding is tore off & down to bare studs. What are some recommended ways to seal & insulate this floor & walls so as not to get damage again. P.S. Upon taking up the flooring today, there were thousands of spiders, both dead and alive & three times that many potato bugs.
Answer:
I'd make sure there was some air movement down there. Hopefully, heated air so the floor above is warm. Even to the extent of drilling 2" holes every three or four feet near the bottom of each 2X6. A good soil neutralizer (available at your local nursery) will look after the roots and vines while moving air will remove the dampness the spiders are enjoying so they'll leave too as soon as their food (bugs) leave.