Table of contents
- How to prepare walls for cement board
- Prepping the walls after the cement board is installed
- Final Prep on the wall
- Prepping a corner bead and the joints
- Taping Joints Using a Membrane
- Prepping the floor for cement board
How to Prepare the Wall for Cement Board
Prepping the Walls After the Cement Board is Installed
Final Prep on the Walls
Prepping a Corner Bead and the Joints
Taping the Corners and Joints Using a Membrane
In your videos you have either tar paper or plastic behind the cement board. Are either of these necessary for proper waterproofing? Can I skip the tar paper or plastic and mount the cement board directly to the studs and use the hydro ban on the outside of the cement board for proper waterproofing?
Thanks, Mike
Mike, first of all welcome! Glad to have you here. No, tar paper and plastic is not necessary unless it’s an exterior wall. If it is an exterior wall than a plastic vapor barrier is needed. Just install the cement board and apply the hydro ban on the outside of the cement board.
Thanks for the welcome. I appreciate your help. It is hard to find people who really know what they are talking about and are willing to help.
Ok. One wall is an exterior wall. I put new R-13 insulation in this wall before I put the tub in. Do I put the plastic vapor barrier over the lip of the tub or do I cut it above the lip of the tub? I assume stapling it would be most efficient, or do I need to use the galvanized roofing nails to prevent corrosion?
Thanks, Mike
Just bring the vapor barrier to the lip of the tub and try to seal it on top of the lip with a bead of silicone. I’m not sure if you have vapor barrier behind the tub or not , but typically I run the vapor barrier on the entire exterior wall from floor to ceiling and then install the tub. You can use staples, that’s what the pro’s use and I do too.
No I do not have a vapor barrier behind the tub. Should I pull the tub out or just go to the lip of the tub?
My local hardware store only carries red gard. Have you ever used it? Or should I just order the hydro ban online?
Thanks
Well if it was my house I would pull the tub to be safe! Red Guard will work. I have never heard of it failing. I just prefer Hydro Ban!
do you have a video prepping the walls for cement board with tarpaper? why did you install the vapor barrier also on interior walls if its not needed? thanks for all the help.
Adolf,
I do not have a video on prepping walls with tar paper. I used tar paper in this situation for two reasons-
1. I filled in that area with insulation for a sound barrier.
2. I covered it with tar paper because I thought it would be good for filming.
I was wrong, because it brings up the question of why I did it. I am sorry for the cofusion!!
In one of the videos you talk about coming back to the lip of the tub, however, could not find where you spoke about the lip. I have a preformed shower pan with a lip similar to the tub you spoke about. I set the cement board on the top of the lip, my question is what do I fill from the top of the pan to the bottom of the cement board with? There is about t 3/4 inch lip on the shower pan.
Randy,
I talk about the lip in the waterproofing a shower videos. Run a piece of mesh tape across the joint of the lip and the cement board and paint it with a waterproof membrane. Then fill the joint with thinset to level it out with the cement board. This will prevent any cracking in that area. Graet questions.
Hi Joe – I just joined your website – great resource! Wish I had this information weeks ago. I floated my seams and corners of my Durock with thinset. I taped the two corners of the bathtub alcove prior to applying the thinset. I checked the corners with the L-square and both are no longer square. Is this “corner bow out”? (You mentioned that in your Prepping the walls after cement board installation video.) I tried not to put an excessive amount of thinset in the corners.
Will this affect tile installation and, at this point, is there anything I can do to correct this?
I wouldn’t worry too much about it. It will give you a little more work when installing. A little bit of a build out in the corner should be fine.
Hey Joe…
What are you prepping the floor with. I cannot seems to find the video that tells you what to prep the floor with. I currently thinset in durarock and screw down every 5 ” in the shower floor. Is this over kill if i am making a pan with the sand mix?
tony
Joe I’m having problems with no sound on many of the videos ! What am I doing wrong
Hi Joe
As this was my first time putting cement board on the shower curb, the edges where i cut the board are not as smooth as what you have done. Would it be advantageous for me to put a skim on the gnarly edges while I am prepping the walls and joints?
–Mike
Hi Joe
Small cracks appeared after second coat of Thin set on wall prep. Not sure what caused this but they have appeared today. I applied the coat last night. Do i need to grind then out? The runs all the way down the seam.
I have sent you pictures to your email address to give you a visual
Regards
–Mike