What to do if there is mold on sub-floor around toilet flange

5/13/2018 at 6:35:14 AM

Hi.

The best solution is take the subfloor out and put new plywood.

Spray antimold on joists and keep structure safe.

Best way to cut the plywood, fond joists and cut it from joists to joists then replace new one. In this case you have support for it. Otherwise, you should use 2x4 or 2x6 for support.

Sincerely

Ideal Dream Homes

5/13/2018 at 7:59:31 AM

Better take plywood out ,and change new one!

5/13/2018 at 8:40:32 AM

My understanding from this picture is: you removed the tile. But you didn't remove the metal mesh and scratch cote. You have to remove that. Most likely plywood under is okay.

Thanks and good luck,

Jim

5/13/2018 at 8:59:51 AM

Hi Fahd. Although it alarming when you find mold, I would not necessarily remove the wood unless it showed signs of decay, rotting or active mold growth. If the plywood is sound, you would be able to use an anitmold spray on it to treat any mold that is there. From the picture, it does not look like you have active mold spores that may cause a health risk.

If you decide to replace the affected area, it is relatively simple process. Although, cutting the affected plywood close to the wall will be a bit of a headache. You can use blocking attached the joists to support the new plywood.

Thanks.

Steve.

5/13/2018 at 9:00:40 AM

Remove as much Mold as you reasonably can, leave at least two inches of wood too your wall and bathtub. Along the perimeter of the hole screw(PL helps too) 2x4 half under old floor and half under the new part you are installing, lay new plywood, screw too joists and 2x4 around perimeter. Make sure toilet flange is properly supported by this new material. Then add second layer of plywood, I like too screw second layer of plywood too the joists with longer screws and then use 1-1/4 inch screws about 6 inchs apart through the rest of my plywood. Remember tiles require minimum 1-1/4 inch of sound plywood for substrate.

5/13/2018 at 9:02:59 AM

Hi Fahd. Although it alarming when you find mold, I would not necessarily remove the wood unless it showed signs of decay, rotting or active mold growth. If the plywood is sound, you would be able to use an anitmold spray on it to treat any mold that is there. From the picture, it does not look like you have active mold spores that may cause a health risk.

If you decide to replace the affected area, it is relatively simple process. Although, cutting the affected plywood close to the wall will be a bit of a headache. You can use blocking attached the joists to support the new plywood.

Thanks.

Steve.

5/13/2018 at 9:05:44 AM

The mold isnt that big a concern as you'll be sealing.it.into concrete. I'd be more.concerned with rot, or a weakened floor.

5/13/2018 at 10:02:17 AM

Replace as much as you can with new plywood....

5/13/2018 at 10:36:16 AM

Hi, Make best attempts to kill the mould , which is almost adjacent floor tiles and further if necessary, remove all the damage boarding, dry the area out and kill any mould , fit new boarding reinstall the tiles.

5/13/2018 at 12:34:09 PM

From the looks of the picture that you posted there is a good chance that the water has penetrated right through your sub floor and into the joist bays. Mold is very bad for your health and even worse for children. It will cause all sorts of respiratory problems. The best way to deal with this in my opinion is to tare up the sub floor in the affected area, set up heaters and fans in the washroom and completely dry out the area. Mold needs moisture to live. That being said, the mold does not die when you dry it out, it becomes dormant. Once you have dried the area out, apply a paint product called kills to any area that shows water stains. This will seal the mold in and stop it from spreading.

I hope this helps

5/13/2018 at 1:27:28 PM

always replace floor substarte (typically 3/4" plywood subfloor) then put 1/4" plywood underlayment on top of that if just lino or wood flooring going on or 3/8" plywood if tile...all good...really easy to do or hire a pro...just cut out whole toilet area and put backing behind then new subfloor pieces...if flange really old or lousy then replace at same time

5/13/2018 at 6:08:30 PM

It's always best to cut the plywood subfloor out from a joist to another joist halfway and then add 2 by 4 or 2 x 6 framing across from joist to joist where it's open plywood so the entire new piece of plywood has a framed perimeter.

5/13/2018 at 9:07:59 PM

Thank you so much guys! Although I am also using backer board under the tiles but after reading your suggestion, I thin I will cut the mold area.