Need Advice About Walling for Bath Remodel

bremdogg55

My name is Greg and this is the first time Ive posted here so please be kind if Ive made a hiccup.

I am remodeling our main bathroom from its original construction. I demoed the bath down to the studs and removed the insulation. After replacing almost the entire subfloor, I have installed a fiberglass tub without the fiberglass surround. I would like to tile around the tub surround and where the tile ends go with greenboard for the remaining bathroom walls. Ive read through a good amount of the advise given in the different forums, but I am still just a little unsure on a few things. I prefer to take my time and do every aspect of the project to the best of my abilty and am not so much concerned with costs. I just want to do it right the first time and be proud of what I have done, knowing I did it correctly and to the best of my abilty.
I would also like to post a picture of what I am working with, but cant seem to figure it out. Any help on that would be appreciated too.

Here are my basic questions:
1) Is it correct to use greenboard or water resistant sheetrock on the interior walls including the ceiling?? With the exception being the tub surround I want to tile which I purchased 1/2" Hardi Backer to use? The bathroom was originally walled in regular plasterboard. Im thinking this was either incorrect low cost way to do it, greenboard is an improvement since the house was built in 1992, or maybe personal preference.

2) I did not remove the drywall attached to the ceiling because there is a mess of blown insulation above it and I was hesitant to remove it until I found out if there is an alternative such as installing greenboard OVER the existing ceiling drywall. Is it imperative that this ceiling drywall be removed and if so, do I just tear it out, clean up the mess of insulation that falls down from the attic, and have more insulation blown in once new green board is installed? I would really prefer to not deal with this mess if possible, and I figured if I was too ambitious and removed it, one of you pros would tell me all I had to do was screw up some greenboard over the existing ceiling drywall.

3) What is the correct sequence of installation?
Hardi Backer, Greenboard on walls, then Hardi Backer for the flooring tile??
Or do I want to do the greenboard, Hardi Backer tub surround, then flooring last?

I really appreciate any and all advice any of you with more experience than me and if anybody can put me in the correct on how to post a few pics of the project, Im sure that would help visually to get the correct advise.

Thanks in advance,
Greg

bjbatlanta

As long as proper paint is used and you have proper ventilation, regular drywall can be used for baths. Normally for a tile surround, drywall is hung "full" down to within 1/2" of the lip of the tub. Cement backer board is installed over the drywall for tile, giving you a lip at the edge of the tub for a bullnose tile. You can add a layer over the existing ceiling as long as proper length fasteners are used (1-7/8" if you use nails, 1-5/8" if you use screws).

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oh'mike

When I rock a bathroom --I use regular drywall except in the tub area--that gets 1/2" Durrock (or orher backer board)

I install the Durrock on the studs--stopping at the top of the tub flange--that void below the Durrock is filled with thinset as the wall is tiled.

Water proofing the cement board is always a good and safe option---I like the paint on liquid membranes,like Hydroban or Red Guard.

---Mike---

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Bud Cline

Some form of cement board for the tub surround walls.
If you intend to tile the ceiling you can simply waterproof the existing ceiling with a liquid waterproofing membrane.

Yes, Greenboard, Hardibacker tub surround, then flooring last?

Cement board requires a moisture barrier on the studs unless you waterproof the face of the board, then no moisture barrier is required.

For the shower walls I would suggest Denshield tile backer. No moisture barrier required behind the board and the surface won't wick water like cement board will.

Hardi is fine for the floors.

bremdogg55

Thank You to those that responded to my post. I think after reviewing what you have written as well as what I have found elsewhere in this forum, I have decided to use the Denshield for the tub surround where I will be tiling. My thought is that if you do no allow water into the wall cavity, then you dont have to deal with how and where it wicks to. Since I am a car buff, I equate it with the same logic as sealing up your vehicle from water as opposed to allowing moisture in and then drilling a hole in the floorboard to drain it. I know this isnt a perfect analog, but I think it drives the point home.

I do want to just clarify a couple more details with you pros please

1) I DO NOT want a vapor barrier behind the area of walls behing the Denshield, even the one exterior wall that will be tiled?

2)I used Kraft faced insulation on the shower wall that is lengthwise paralell to the tub. Do I need to slit the facing before installing the Denshieldor is it OK to leave it.

3) Can I go right over the top of the Denshield with modified thinset to set the tiling or is there another step involved?

4) The transition from the Denshield to the vertical tub flange has caused me some concern. It appears that the preferred way to do it is to stop the Denshield just above the vertical tub flange and fill in the gap with modified thinset and tile over. Do I need to waterproof the thinset in this area as it would seem that it would be able to allow moisture to get through to the wall cavity since its not waterproofed? OR do I space out the Denshield from the studs (the verical tub flange is 3/16 thick) this thickness and run the Denshield over this vertical tub flange leaving a small gap between the Denshield and the HORIZONTAL surface of the tub and caulk at the bottom, then finish with tile? This is my biggest question and I seem to read about folks doing it both ways.

I am located in the Northwest in Washington State. Although Im not going to live in this house forever, I want to do this in a manner that will produce the longest lasting job, not necessarily the cheapest or quickest as I would expect a good amount of you contractors out there encounter with many customers. My opinion is that there are many ways to accomplish these improvements, but some are much longer lasting and that is the info im after. To put it in a nutshell.... How would you accomplish these improvements in YOUR dream home, not some mass produced homes produced quickly and with minimal expense. You can paint a car 100's of different ways, but if the paint flakes off or bubbles in 3 years instead of 20 years, then it really wasnt a good job. It just looked good for awhile. To put it in my terms..

Thank You in advance to all of those that respond and have responded.

Greg..

P.S. How on earth can I find out how to post a picture in my posts?

Bud Cline

Correct.

I know the "slitting the insulation face-paper" turns up as a recommendation in some places but I wouldn't do it if it was me.

Denshield has a water resistant face coating (unlike cement board). You will need to address the seams and the fastener penetrations to maintain total water resistance. I use mesh tape for the seams and coat it with liquid waterproofing. The mesh will collect the waterproofing and seal nicely. It may take more than one application however. I also paint the fastener heads and holes.

Stop the wallboard on the top of the flange, don't go over it. Caulk that juncture totally. In some cases the caulk will resist bonding to a raw edge of Denshield but you can make it stick. Drag your finger through the caulk and stitch it upward into the edge of the board.

Install the tile so as to pass the gap between the wallboard and the tub top. I see no reason to fill the gap with thinset but if you can't live with knowing that void is there then fill it. You will eventually apply caulk to the tub and tile juncture so it really doesn't matter if that void is there or not.

I don't race through any of my jobs and what I am telling you is my current method. I can proudly say that I have never had a job failure of any kind in my thirty-five years of doing this kind of work. Not one.

Somewhere here there are instructions for posting photos. I have a helluva time doing it myself.

What else?

Gary in WA

Welcome to the forum!



Post a picture; How To Post Photos Using PhotoBucket Or Flickr

OR; How to attach a photo to a post
These are found as "stickies" at the beginning of the "How to" titles.

Thinset between the backer board/tub could let water through by the different expansion/contraction rates from the temperature changes of the two very different materials and mass thickness, causing a crack there. Also, thinset could wick water through it (capillary action) to the backer core, unlike caulking. I'd use caulking in front of backer rod (for any larger gaps) to have a "hourglass" shape for optimum stretch in case any water gets past the caulking at tile/tub joint. Only two surfaces with caulk, tub/board, not three- tub/board/tub lip. Step #5; http://www.crossroadsci.com/LinkClic...t.pdf&tabid=80

Or leave it empty as said. My 2 cents….

Gary

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tazangel52

so does the mortar for the tile installation stick to the cement board after you apply the liquid membrane product?