I recently posted about my baloon framing farm house and I had to remove the inner boards to continue with the project, after some good advice here I will be putting plywood sheets back onto the studs this will give bring back the support that was removed.
My question is when I go to drywall do I need to strap the ply or can I drywall straight onto the ply, I have 16″ centres so very little movement and of course I will screw the ply really well to the studs.
Thx
Dave
Replies
You don't need plywood on your interior walls. There are countless millins of homes all over the world built just like yours. I'm wrking on a 30 building condo project right now in the Florida hurricane zone that are all built just like your house. If you want to be sure you can glue and screw the drywall to the studs. For less than what the plywood plus labor would cost you could blow in foam insulation and make your house totally rigid and insulate it.
Let me explain my project a little better.
My farm house in Ontario is over 100 years old, it is a baloon framed with 12" boards on the outside of the studs and 12"boards on the inside plus double brick. I had to remove the inner boards to run electric and will be sprayfoamimg all exterior wall, my issue has been that removing the inner boards (may) reduce the strenght of the house as I have technically removed half of the support ?.
I did ask previously if the inner boards needed to be put back and the general reply was yes, plywood was the best as the original boards that I remove were in bad shape.
Due to the house being old al of the walls, cellings, floors are out so we have straightend them all out so the ply would be going onto a flat surface, hopefully with minimal movement.
So do you still think I need ply ? or leave it off completly and not worry about loss of support and if ply is added can I drywall directly to it.
Again Thank you for your replys.
Dave
If the boards on the outside of the studs are sound I see no reason to put anything on the inside.
The boards on the inside of your house were there because boards were what was avaible in the daus before drywall , not because they were needed structurally. Once you get foan sprayed on. your house will be stiff as a board! Here in south Florida one inch of foam sprayed on the underside of your roof is equivalent to 8 penny ring shank nails every 6 inches and satisfies the state huirricane code. More foam wil be even stronger. Forget the plywood and hang some drywall.
You've got several issues to confront.
While boards on a bias still meet minimal shear requirements, they're completely inadequate if you want some serious wind / quake resistance. There, experience has shown a real need for at least 3/4" plywood - especially if the wall has several penetrations for windows or doors, and especially if these penetrations are near the corners of the house.
You'll also want to shim / plane the walls flat before you add the plywood, or you will forever have a wavy wall, caused by any bow or twist to the studs.
Codes do not distinguish between plywood and framing for attaching drywall; you'll still have to follow the same screw schedule.
You can drywall straight over the plywood. The only reason for strapping would be if that helped you flatten irregularities in the wall.
To everyone who thinks the house is fine with no source of sheer bracing you should stick to non-framing issues. As stated the house wouldn't have anthing for sheer if the ply wasn't installed.
Adding ply to the interior of old houses is done all the time and is a great way to stiffen things up - that gets two thumbs up from me.
The house has plenty of shear bracing with 12" boards on the outside. The foam will provide even more. Plywood is totally uncesary and pointless.
You need to read the posts more carefully before you go stomping on people.