DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Remodeling (
-   -   How much mortar to remove (

hurtman 03-18-2013 08:23 AM

How much mortar to remove
I'm using the Kerdi membrane in a shower renovation. I'm using Ditra unmodified mortar and Hardi backer. The first 2 pieces of Kerdi I put up didn't hold well because I didn't wet the backerboard enough. I've removed the Kerdi. Question is how much mortar do I have to remove for rehanging the Kerdi? Do I need to scrape down to the backerboard if it is adhering well?


Windows on Wash 03-18-2013 09:09 AM

How much mortar (square footage) did you put up?

If it isn't much, I would remove it and get back down to the back board.

hurtman 03-18-2013 09:32 AM

It's about 36 square feet of coverage. What would you suggest- a scraper and sander?

Windows on Wash 03-18-2013 10:16 AM


You don't want to be breathing in mortar dust. Not good for the lung health with the portland and/or silica.

Blondesense 03-18-2013 10:54 AM

Ditto on the scraper. You don't want to be breathing CBU dust either.

How much effort did it take to pull it off?
I've never used Kerdi, but I suggest doing a bit more research. My understanding is even if done properly, it will be fairly easy to pull off. You may be fine the way you were doing it.

retired guy 60 03-18-2013 01:47 PM

A scraper will work fine but I'd turn to my Fein MultiMaster with a blade made for removing mortar. My oscillating tool has become my favorite go-to tool. And prices for less expensive models are really reasonable.

hurtman 03-18-2013 07:32 PM

It's not coming off very easily. I think I'm going to do a redo with some of it still adhering. I'm not going to get it all down to the backerboard.

Fix'n it 03-18-2013 09:09 PM

its been a few years sinse i used kerdi. but back then they said to only use regular drywall.

All times are GMT -5. The time now is 05:34 PM.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1