What is the best type of mastic for laying shower floor tile?Are there additives that can be added to mastic to make it more resilient to the type of location it is in?

Since you are bedding the tile over a concrete floor, just use regular thin set and an acrylic additive. Grout is what keeps the underneath dry not the mastic. Some people use Acrylpro for shower floors but I don't.

Yeah, mastic is not correct for this application! As noted by Ma0641, thinset mortar is correct in most applications, but our best answer would come by knowing exactly what tile/stone material you are using here, OK?

You posted a question over at plumbing regarding an incorrectly pitched concrete shower floor, Bubblechaser... did you read my response yet? If not go over to plumbing and read... please respond after with any questions, OK?

Mark

Bubblechaser,

Don't even think about using any mastic in a shower, especially the floor. You will be removing the floor within a short time.

Use only real thinset mortar which only comes in powder form. What type of waterproofing will you be using? Got any specific products in mind?

Jaz

Hi guys,I'm putting down 1 inch natural stone tiles in a 12 inch sheet with a mesh backing.Up till now I have been getting my info from LOEWS and Home Depot.Good stores ,but they don't necessarily hire people with background and experience.I worked for LOEWS once and was thrown out on the floor with the promise of training.Good people ,but I think each department should hire one experienced person,maybe even retired.They could take others under their wing an train.I know ,not cost effective.Thanks for the help.

You're right about the nice people at the big box stores, they're very nice, but it's difficult to find anyone that knows more than the minimum. In 20 years I've only found one person in the flooring department that knew how tiles are installed. He was a tile setter working there till biz picked up again. He was gone within 2 months.

Natural stone for a shower, and a floor no less? I wish you luck because you're going to need it. Natural stone for showers can be a nightmare.

As you know I read and added to your other thread in plumbing. You were given very bad advice and if I remember you've already done much of the work. If you'd like to review it, do it here.

Jaz