Schluter-Kerdi board to redo an in-place shower

In older homes like these, the main remodeling goal is often a more welcoming, more social, and more functional kitchen.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Get home building tips, offers, and expert advice in your inbox
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial NowDig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now© 2025 Active Interest Media. All rights reserved.
Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.
Get home building tips, offers, and expert advice in your inbox
Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.
Start Your Free TrialGet complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.
Already a member? Log in
Replies
Your plan should work as long as you add enough support behind the kerdi board (horizontaI nailers/battens/ shims etc) but I cant image why you couldnt cut the existing shower up into pieces and remove it leaving the walls intact.
I probably should just cut it out. I was trying to minimize mess and time as it's the only bathroom in the house. But you're right. I'm coming around to it. The corners are all curves and will require a lot of shimming to turn into right angles. Was hoping there's an existing product specifically to go over old acrylic shower enclosures.
You can even tile over tile, but your tile may only be adhered to a plaster wall and that isn't a good substrate. You could also use a product like Durock concrete board with an applied Kerdi waterproofing membrane. ...or the Kerdi board with integrated membrane as you suggest. (The Durock option is the cheaper option though.)
You'll be assuming that there is no mold/rot behind the shower walls.
Why not go with a Kerdi shower pan while you're at it.--but they do get expensive for a large shower bases.
I actually suspect the worst behind the existing walls. So yes, I should just cut it out in pieces and do it from scratch. it would be so cool though if there were thick rubber-backed, adjustable "studs grids" that you could just screw into an existing acrylic shower, make a nice rectangle and then wall over. Double the waterproofing ;-)