Use any high quality unmodified thinset to bond the shower tray to the plywood floor. It doesn't matter what the thinset manufacturers say, as your warranty comes from Schluter. So use what they recommend.

I personally use Mapei Kerabond for unmodified installations.

The only time a modified is used, is for installing Ditra over wood subfloors.

is anyone out there using mer-krete

I use Laticrete 9235 liquid and cloth and I go right over the curb as well and it is extra insurance and it keeps moisture from going through the mud to the pan and then to the weep holes and eventually into the drain.

The 9235 can be used as a pan base instead of the Chloraloy as well, the inside corners fold flatter then the vinyl does too.

home depot has a product called blueseal you can find it in the tile section or the cement section they use it for foundations as well very sticky stuff !

Brainfrost, just curious, what is your usual method of waterproofing a shower? I've just been doing my first Kerdi shower this week. Interesting stuff.
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Anna Jennifer

[url="http:www.drivenwide.com"]discussion[/url]

I use Flextile WP980 with fabric - very similar product to Laticrete 9235 (also have used) and Flextile is Canadian eh.

Hi Everyone, first question here so I hope I'm putting it in the right place. I am building a shower with Densshield, pre inclined mudbed over concrete, 40 mil membrane, and mudbed.
1. Do I need to waterproof the final mudbed before tiling?
2. I thought the moisture was suppose to flow through this to the weep holes in the drain.
3. What should I use if waterproofing is needed?

I looked for this specific answer here and on other sites but couldn't get the difinitive answer I need to proceed.

Thanks!

Jim Kaiser in Minnesota and yes, I've lived in Canada!

Welcome Jim

You do not need to apply any surface liquid type waterproof membrane. It wont work with the style of mud bed you have built unless you modify the area around the drain. I really don't see any point in doing that.

Just carry on with what you have.

I just noticed you were using DensShield. Please make sure you follow the instructions for a shower pan install in the following link. DO NOT embed the DensShield in the mud pan!

http://www.gp.com/build/DocumentViewer.aspx?repository=BP&elementid=3112

Hi Jim,

Next time start your own thread.

Do as Randall says, especially the part about reading Dens-Shield instructions on how to build a shower. It's a good reason NOT to go with Dens-Shield.

Ask if you don't see the problem.

Jaz

Dens-Shield is a great product, but it does have some limitations. If you have not started yet, I would encourage you to get a Schluter Kerdi drain. install dens to the floor, Build your shower pan with that drain and either liquid water proofing or Kerdi. Run it about 4 inches up the dens. You will save yourself a lot of time and hassles with the kerdi drain.