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Timur 02-16-2013 05:56 PM

Bathroom remodel: walls and floor prep
Hello eveyone,

I plan to remodel my bathroom in a 30 year old house. I moved to the States couple years ago and amazed how far you can go on your own whe repairing your house! So I decided to give it a try, and while researching found this fantastic forum.

I have a bathroom with painted sheetrock walls and vinyl floor. I want to tile walls top to bottom, to tile floor and to replace a tub. Optionally, I was thinking of installing heated floor as
well. Tub replacement I plan to leave to professionals, the rest I want to tackle myself. Also, I want to replace the door. I have a pretty good idea on how to lay tile (did it before), but the walls and floor preparation is new to me.

The course of action:
1. Remove all fixtures, vanity, toilet, door and door trim (pretty straightforward)

2. Cut the sheetrock with circuliar saw (1/4 in?) as close as possible to the ceiling. I don't want to do anything with the ceiling, and not sure how to remove the rest of sheetrock. Would that
work? Also, this will mean that topmos tile will partially be adhered to sheetrock. Is it reasonable to do?

3. Remove vinyl and see the condition of underlayment. When I look in the register opening I see there is a vinyl, some thin layer under it, then two layers of plywood (underlaynet and subfloor).
From crawl space I see that there are patches under the bathroom, so I suspect that subfloor may need a repair. How do I repair the subfloor? My thinking is to use a circuliar saw to cut out the
piece of damaged subfloor up to nearest joists, and replace it with the neew piece of plywood. In this case, do I need to leave 1/8 in between old and new pieces of subfloor? Do I need to seal this seam? What if I don't
have an accessible joist? Do I make it up from the crawl space by using a 2x4?

4. Important: now my vinyl is flush with carpet in the hallway, if I remove vinyl,install backerboard on top of underlayment and put tile, bathroom floor will be considerably higher. How can I avoid
that? Can I remove plywood underlayment and place a backerboard instead? Or I have to keep the underlayment intact? If underlayment can be removed, I may consider adding heated floors, otherwise it is goingto be too high.

5. Install the new bath (wouldn't do it myself)

6. (Optional) Install and hook up heated floors (hook up done by electrician).

7. Install vapor barrier (polyethilene). Tuck the top part under sheetrock. Should it go under the tub lip?

8. Install floor backerboard. Spread adhesive thinly on subfloor/underlayment and put backerboards.Leave 1/4 in on perimeter, 1/8 in between the lists. Screw backerboards to the subfloor after
placing all sheets. Do I need to screw to joists, or just screwing to subfloor is good enough? If I need to screw to joists, I need to make sure that seams are on the joists then. Last step is to seal the seams.Also, is it easy to do holes in backerboard (e.g. for toilet pipe?)

9. Install wall backerboard (screw to the studs). On the walls, top is tight with sheetrock (see point 2), not sure about the bottom. Should it be 1/4 inch from subfloor (so that it is level with floor backerboard?) Wall backerboard should be 1/4in from the tub lip.

10. Install new door casing and trim. (Which is a task by itself, but not a subject of this post)

Phew, thanks for reading that far. It seems at this point I will be ready to start putting tile. Does the sequence of steps above makes sense and do I miss any steps? Any feedback is highly appreciated!

Fireguy5674 02-16-2013 07:17 PM

Welcome to the sight. Sounds like you have a pretty good handle on what you need to do. I will go through your steps by the numbers and try to answer your questions and add a couple of suggestions.

1. Yes

2. Other than the tub surround area where I figure you will have a shower you do not have to remove the drywall. If it is in good shape you can tile over existing drywall. If you decide to remove drywall you can replace it with green board (mold resistant), prime and tile over that. In the tub/shower surround area you will need to use 1/2" concrete backer board and coat it with a water proofing coat such as Red Guard (what I use instead of plastic). To remove the drywall and leave the ceiling intact I would cut the dried mud and tape right in the corner between the wall and ceiling with a utility knife and remove the drywall. The drywall on the walls should be below the drywall on the ceiling. Your circular saw idea would work but cause a great deal of dust. Wear a serious mask.

3. I would remove the vinyl and underlayment from the floor. Just get it out of there and start fresh. If you find you need to replace any subfloor use your circular saw too cut down the center of your floor joists and remove any bad spots. Patch back with new plywood. Glue and nail the pieces as you put them in. A little gap is alright, but don't get to hung up on that. You do not need to seal those seams. If needed glue and nail a 2x on the side of the floor joist to carry your patch.

4. Remove underlayment and add heat if you like. It is a nice thing to have in the winter.

5. OK

6. The heat system I use goes above the concrete board and I install it right before I lay tile. Follow manufacturer's directions.

7. The Red Guard that I use goes over the concrete board but if you use plastic here do not put the plastic behind the tub lip. Any moisture should drain back through grout to tub not down the wall.

8. Install backerboard as per manufacturer's directions. They all have web sights with detailed instructions. Do not align backboard joints with subfloor joints and do not end up with four backerboard corners together. That is covered in their instructions. Screwing to the subfloor is fine. Cutting round holes is a little more fun but not bad. I do it with the same scoring tool I use to cut the board, but others here prefer different methods such as a concrete blade in a 4 1/2" grinder.

9. At the bottom of the wall the gap is not critical you are going to add 3/8 to 1/2" of tile and thinset before you set the tile on your walls. Gap at tub sounds good.

10. I would not hang the new door until I had the floor tile installed. You can set the door frame on top of the tile instead of having to cut the door frame to allow for the tile to go under it unless that will mess up your appearance outside of the bath.

Only other thing I can think of right now is if you decide to put tile over your existing drywall is the paint. If you have a high gloss paint I might wipe it down with a deglosser to improve the adhesion of your tile. Also if you decide to tile over any drywall you can use mastic to set the tiles. You will need fortified thinset over the Red Guard product in the shower if you decide to go that way.

If you have more questions don't be shy.
Good Luck

Timur 02-16-2013 07:55 PM


Originally Posted by Fireguy5674 (Post 83710)
I will go through your steps by the numbers and try to answer your questions and add a couple of suggestions.

Great, thanks!

nealtw 02-18-2013 04:13 PM

I'm impressed both with the depth of the questions and the answer from fireguy

Timur 02-20-2013 05:26 PM

thanks a lot for such detailed answers!

I have a couple follow-up questions.

on 2: ceiling above the tub is about 8 in lower than in the rest of the bathroom, so cutting the mud and tape would likely not work. Is there a better way of cutting drywall than with a circular saw?

on 10: if I install door trim on top of tile, how do I fix it? With a glue?

nealtw 02-20-2013 06:34 PM

The ceiling drywall was put up first even in the drop area. If you run a knife along that joint you will cut the tape and then you can just smash into the drywall on the wall and rip it down. If you think the wall was put up first run the knife blade in to follow the plane of the ceiling. You can cut thru drywall with four or five passes with a knife, less dust. Put molding up first and tile to that.

Fireguy5674 02-20-2013 09:45 PM

Like Neal said, cut the drywall with a utility knife at the ceiling corner and remove the drywall. You can cut drywall with a utlity knife anywhere you need to.

I would lay the floor tile, hang the door and trim it, then set the wall tile to the door trim.

Ask again if I missed anything else.

PS have you ever hung drywall?

Timur 02-22-2013 10:41 PM


Originally Posted by Fireguy5674 (Post 83911)
I would lay the floor tile, hang the door and trim it, then set the wall tile to the door trim.

Oh, all right, I was thinking you are talking about setting door trim on top of wall tile. For the floor it makes total sense to do tile first.

Originally Posted by Fireguy5674 (Post 83911)
PS have you ever hung drywall?

No, I didn't. I've seen a lot of pictures though :)

Fireguy5674 02-23-2013 10:56 AM

When you cut drywall you score it on the face side with a utility knife, snap the board at the score line and cut the backing with your knife. If you have a cut which forms a corner where you can't snap the board both ways, you will need to cut through the drywall one direction and snap it the other way. Easiest to cut through with a course blade hand saw or you can do it with your knife. Fastest and easiest to use a jab saw. $8 at any tool store.

In area like a bathroom you should be able to cut your drywall so you don't have any butt joints in the wall. Makes finishing the drywall easier. Of course if you are going to tile top to bottom won't need much of that.

CallMeVilla 02-23-2013 11:20 AM

Great discussion here ! Another note: I use a RotoZip when cutting drywall that is mounted on the wall. This works for careful demolition or exploration. It also allows you to cut notches faster for odd shapes . . . or cut-outs for electrical boxes.

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