New bathroom install on existing walls

Question Icon
Posted by: from Plymouth
1/9/2022 at 8:13:08 PM

I'm going to install a bathroom on existing corner, the walls are drywall covered by wood paneling and the ceiling is drywall. Do I need to cut the celing and drywall/ paneling out and get down to the studs?

User Icon
Date/Time1/10/2022 at 1:21:20 PM

I would strongly suggest that you gut things down to the studs. Then install the proper water resistant cement board or similar covering for the base walls and tile over that. Regular drywall will absorb the moisture and may become soft, ... plus, may become moldy, which is a health hazard. Take your time and do it properly.

User Icon
Date/Time1/10/2022 at 11:57:43 PM

A new bath I presume? you do not need to do it but it is wood panelling? and who knows what is behind the walls?, unless you want a butt ugly bathroom with uninsulated freezing walls, I would gut it all and do it right from scratch to code. Also you need to install a ceiling fan and heat supply by code so you are likely gutting ceiling anyway.

Note: by code you are not allowed to put water lines in exterior walls unless you do a "false wall" so bone up on what that means/how to do it by code or hire a contractor who knows what they are doing.

User Icon
Mahyar (Mayyar) from Reno Building Canada Inc. in Newmarket
Date/Time1/11/2022 at 1:03:30 PM


1.You need to take out all drywalls in shower area for sure.

2.If the insulation and vapour barrier are not good, replace them with a proper R value.

3. Install Cement board or densshield tile backer board

4. You need to do the waterproofing after. (3 different systems... all are good)

5. Now it's ready for tile...

If you want to DIY, please spend time and watch the useful videos.

Do it right

Goog luck

User Icon
Date/Time1/12/2022 at 12:47:32 PM

Hey Christopher,

When it comes to re-constructing an existing room, it is necessary to remove the interior finishes (panels) and drywall to have the room exposed to the studs.

Having the room reduced to the studs will allow for proper planning of the plumbing/electrical requirements of the project. This will also reveal if there are any issues (mold, moisture damage, etc).

Because you are looking to construct a bathroom, moisture barriers, dent shields etc will be utilized in the construction of the shower walls.

I hope this helps!


Chantal Drepaul

Senior Project Manager

User Icon
Date/Time1/12/2022 at 5:10:53 PM

Yes you will have to cut drywall otherwise how will you ruf in plumbing pipes and fixtures.

Search the TrustedPros directory and discover the best contractors in your area.

Find your home service pro
Great renovations start with a great contractor.

Since 2004, TrustedPros has been helping homeowners find the right contractor for their home improvements and repairs.

Post Your Project

Within hours you'll be comparing offers from top-rated professionals. It's free to post and you're under no obligation to hire.

Trustedpros Inc. does not warrant the accuracy, completeness, safety, legality or usefulness of any Content, or Whether Content is Current and up-to-date, and TrustedPros Inc. Shall have no liability whatsoever with respect to your use or reliance upon any content or for content being removed or otherwise ceasing to be available. Please refer to the terms and conditions of use of this websites for more details.

Get quotes from top-rated contractors