When I built the adition to my house I used a 5/8th ply sub floor. I understood that I would need at least 3/4″ under areas to be tiled. Now that I’ve cut through to the existing house, I see that I have to raise the adition’s sub floor by 9/8 to match the subfloor of the existing house. Oops mis calc.
I could laydown sheets of 1/2 ply followed by sheets of 5/8 ply. I’ve thought of saving money by laying 1/2″ strips 6 inches wide on the diagonal every 12 inches and cover that with 5/8 ths ply. Would that work? What’s the best way to do this? gypcrete?
An ex-boat builder treading water!
Replies
For areas that will be under tile or stone, use sheets as sheets. For other areas, I guess that you could get away with the strips -- but the labor's gonna be a killer.
Unless you're the lead dog, the view just never changes.
Thanks for the reply. Well three years on as a DIY project, the extra day is probably worth the $300 CDN saved.An ex-boat builder treading water!
so now ... your working subfloor is going to be 5/8th?
good luck there ... even the carpet is gonna squeak!
btw ... tile ... 1 1/4 is the new minimum. 1 1/8th advantec will work too ... but good/common is 3/4 + 1/2. Glued and screwed.
it's your house ... but I'd never consider "saving" $300 for a lifetime of potential problems ... every other footstep ... 5/8th over a void. The house won't fall over ... but that'd make for pretty crappy construction.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
Thanks for your comments.
I was always going to beef up the subfloor under the areas to be tiled. In retrospet a 3/4 subfloor throughout would have been better. I do have one area that squeaks from a couple of the i-joist hangers by the stairway to the basement. I have got to do some reinforcing there. The rest of the sub floor glued and screwed t&G 5/8ths is all squeak free.Do you recommend 3/4 for sub floor?An ex-boat builder treading water!
minimum 3/4.
still ... under the tiles ... 3/4 + 1/2 ...
Jeff Buck Construction
Artistry In Carpentry
Pittsburgh Pa
Bowbear-
I think the idea of putting down strips is a waste of time. By the time you get done cutting them and nailing them, you will have time invested for essentially naught. If you put the full sheets of plywood down, at least it will add a little strength to the floor. The strips won't.
You could also consider using Homosote Board. It's a cellulose based product that will serve somewhat as a soundproofer/insulation as well as the filler you need. Actually, Homosote does have one product that is extra thick, maybe 1 1/8? Google it and see what you find.
If you have already put three years into the house, don't scrimp for a few dollars. it's not worth worrying about.
Don K.
EJG Homes Renovations - New Construction - Rentals
I'm convinced. I'll add 3/4 over all.An ex-boat builder treading water!
"Now that I've cut through to the existing house, I see that I have to raise the adition's sub floor by 9/8 to match the subfloor of the existing house. Oops mis calc."
Why didn't you cut a hole in the house first to see where your floor height should be? That's the first thing you're supposed to do from day one.
Thanks Framer,
I knew this would be a long term project. The addition is located to the side of the house, where there hadbeen a car port. I promised DW that construction would not intrude of the existing house until the last. Yeah, it would have been better to cut a hole.An ex-boat builder treading water!
Yeah, it would have been better to cut a hole.
It's understandable that a boat builder wouldn't think to first cut a hole in the project! :-)
Add one layer of 3/4" Plywood , the 3/8" you will be short will be taken care of with a threshold.
mike
I do a lot of floor tiling and the size of the plywood is not as important as using two layers to offset the joints and any movement. Ceramic or natural stone should always have two layers with offset joints or cracking can occur, strapping the floor then using 3/4 may not work as any thinset mortar bed reuires two layers of plywood.
I would go with 3/4 with 3/8 over or what ever gives you the needed thickness, the smaller size on top nailed or screw the top layer every 6"
A second possiblity is to use 3/4" plywood with a mesh and scatch coat over this is a older method but still the best and some tile guys still only do floor this way.
George