Designing Kitchens and Bathrooms - Two bad subfloor boards under tub
Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.View Full Version : Two bad subfloor boards under tub
arw1970
05-13-08, 01:35 AM
Hello,
I've just begun a major renovation of my bathroom. I'm a first-timer at this, but I've got a limited budget, so I must do most of the labor myself.
There was a leak behind the tub faucet that rotted the drywall behind it and also damaged the subfloor next to the tub. The drywall was also unevenly installed by a former owner, so I ripped out all the drywall surrounding the tub. I'm installing a new toilet and vanity, so I pulled out the old ones so I could get at the subfloor.
My first question is about the subfloor. Two of the main subfloor boards under the plywood are damaged. The damaged area is about 1 to 1 1/2 feet on each board. When I go into my basement I can see that the bottom of the boards have white staining and some darker discoloration where water has dripped between the gaps. The joists are fine. From the top, the boards appear dark (almost black), but if you push into them with a screwdriver they are quite solid. So, they look bad, but feel rather strong. My gut is to replace the bad sections, however the worst board runs under the part of the tub and the wall to the hall closet (non-supporting). The second one is half under the tub. The only way to cut the bad section out is to pull the tub out. This is possible because the bathroom is mostly gutted, but as a first-timer, it feels a bit overwhelming. I had intended to leave the tub in its place and have it reglazed. Is it mandatory to replace 2 small sections of damaged but functioning boards if it means yanking the tub?
While I don't feel the boards are dangerous, I'd like to sell the house in a couple of years and am afraid buyers (and their house inspectors) may be afraid if they go to the basement and see two badly waterstained boards under tub. But, oh what a pain to fix!
My second question is about the tub itself. I've searched this site and others and it appears that the tub is sufficiently supported but I wanted to make sure. It has a styrofoam bed as its base, no morter and the old plywood portion of the subfloor edged up to the tub, but did not go under it. The styrofoam sits directly on the subfloor boards. Is this adequate or should I put plywood under the tub if I have to yank it out to fix the subfloor?
Sorry for the length of my post, and thanks so much for your replies!
I've just begun a major renovation of my bathroom. I'm a first-timer at this, but I've got a limited budget, so I must do most of the labor myself.
There was a leak behind the tub faucet that rotted the drywall behind it and also damaged the subfloor next to the tub. The drywall was also unevenly installed by a former owner, so I ripped out all the drywall surrounding the tub. I'm installing a new toilet and vanity, so I pulled out the old ones so I could get at the subfloor.
My first question is about the subfloor. Two of the main subfloor boards under the plywood are damaged. The damaged area is about 1 to 1 1/2 feet on each board. When I go into my basement I can see that the bottom of the boards have white staining and some darker discoloration where water has dripped between the gaps. The joists are fine. From the top, the boards appear dark (almost black), but if you push into them with a screwdriver they are quite solid. So, they look bad, but feel rather strong. My gut is to replace the bad sections, however the worst board runs under the part of the tub and the wall to the hall closet (non-supporting). The second one is half under the tub. The only way to cut the bad section out is to pull the tub out. This is possible because the bathroom is mostly gutted, but as a first-timer, it feels a bit overwhelming. I had intended to leave the tub in its place and have it reglazed. Is it mandatory to replace 2 small sections of damaged but functioning boards if it means yanking the tub?
While I don't feel the boards are dangerous, I'd like to sell the house in a couple of years and am afraid buyers (and their house inspectors) may be afraid if they go to the basement and see two badly waterstained boards under tub. But, oh what a pain to fix!
My second question is about the tub itself. I've searched this site and others and it appears that the tub is sufficiently supported but I wanted to make sure. It has a styrofoam bed as its base, no morter and the old plywood portion of the subfloor edged up to the tub, but did not go under it. The styrofoam sits directly on the subfloor boards. Is this adequate or should I put plywood under the tub if I have to yank it out to fix the subfloor?
Sorry for the length of my post, and thanks so much for your replies!
HeresJohnny
05-13-08, 09:39 AM
Just because the boards appear darker in color or are stained doesnt necessarily mean they are damaged. It sounds from your screwdriver test that that is all that is wrong with them. Do the screwdriver test from below as well. If the integrity of the boards is still good, I'd not replace them because they are discolored.
As to the tub, when you stand in it, does it flex or move? If not then you are fine.
As you have already seen, sheetrock is not a good choice for a tub surround. If you will be tiling the surround, use cement board instead.
As to the floor, if you intend to install ceramic tile you will first have to install a minimum of 1/2" plywood over the plank subflooring. Then cement board or an isolation membrane.
Once you know exactly what direction you are headed in, come back and ask lots of questions. This way you will know its done right.
The obvious, make sure you have resolved all water leak issues before going any further and let everything dry out.:)
As to the tub, when you stand in it, does it flex or move? If not then you are fine.
As you have already seen, sheetrock is not a good choice for a tub surround. If you will be tiling the surround, use cement board instead.
As to the floor, if you intend to install ceramic tile you will first have to install a minimum of 1/2" plywood over the plank subflooring. Then cement board or an isolation membrane.
Once you know exactly what direction you are headed in, come back and ask lots of questions. This way you will know its done right.
The obvious, make sure you have resolved all water leak issues before going any further and let everything dry out.:)
arw1970
05-13-08, 01:21 PM
Thanks for the reply. As the planks are drying out, I'm becoming more confident that they don't need to be replaced. They're just stained.
I've located the leak and fixed it, and I will be using cement backer board to surround the tub. The person who last renovated the bath did an awful job. I'm not going to repeat his mistakes!
Thanks for the advice on the plywood thickness. I wasn't sure about that.
Well, back to work. I've got a bit of the old plywood to still pull out then I'm off to HD to buy the new materials.
Thanks!
I've located the leak and fixed it, and I will be using cement backer board to surround the tub. The person who last renovated the bath did an awful job. I'm not going to repeat his mistakes!
Thanks for the advice on the plywood thickness. I wasn't sure about that.
Well, back to work. I've got a bit of the old plywood to still pull out then I'm off to HD to buy the new materials.
Thanks!
HeresJohnny
05-13-08, 02:01 PM
Make sure you install a 6 mil poly vapor barrier behind the cement board. Also insulate any exterior walls.
As for the floor, make sure all planking is fastened securly to the joists. Use extra screws as necessary. The plywood should be screwed to the planking only. Use deck screws just slighty longer than the thickness of the plywood and planking. The idea is to screw the plywood into the planking only avoiding the joists. This helps to isolate joist movement from the tile above. You want screws every 8" in the field and 6" around the perimeter of the plywood. Leave a gap of 1/8" between plywood sheets for movement and leave a gap around the perimeter of the room as well.:)
As for the floor, make sure all planking is fastened securly to the joists. Use extra screws as necessary. The plywood should be screwed to the planking only. Use deck screws just slighty longer than the thickness of the plywood and planking. The idea is to screw the plywood into the planking only avoiding the joists. This helps to isolate joist movement from the tile above. You want screws every 8" in the field and 6" around the perimeter of the plywood. Leave a gap of 1/8" between plywood sheets for movement and leave a gap around the perimeter of the room as well.:)