View Full Version : Mortar Bed for Acrylic Bathtub

08-14-2008, 10:23 AM

We bought a Rona brand acrylic bathtub from Rona (Canada, eh!) and it appears it is made by Aciflex (www.aciflex.com, I think the model is Bahamas / A2-221). The installation manual says that quote "It is recommended that a layer of mortar be applied and covered with 2 mil polyethylene sheet to facilitate leveling". 3 questions:

1. Is this step necessary?
2. If yes, what exact mortar product do I use?
3. Steps to apply the mortar?

I contacted the company as well.


08-14-2008, 10:45 AM
For maximum longevity (you'll end up with stress cracks from flexing if you don't) and quiet operation (you'll likely have squeaks as things move if you don't), you want to do this!

A sand mix (mixture of mostly sand with portland cement) works. You can buy it already mixed...just add the water. It will be like wet beach sand, and does not flow. Add enough water so it holds together when you squeeze a handfull - it should not be dripping wet. You'll need something like a hoe to mix it. Plastic on the subfloor, too. This will prevent it from having the moisture sucked out and leave it to chemically cure into the cement.

Make sure you tamp the tub down so it is level front to back and side to side after setting it onto the mortar you've thrown on the floor. You don't want to compact it prior to setting the tub down or it would be like trying to push a brick into hard earth - difficult. You can't lift it up if you push down too much, since the stuff compacts and won't rebound - you'd leave parts unsupported. It should cure overnight, then you can do whatever you want to it. It won't look like a concrete sidewalk - it will be sandy and porous. That's okay, it is quite strong in compression and you won't be walking on it.

08-14-2008, 01:45 PM
thanks I'll try the sandmix. Can I get this stuff at Home Depot? Is it called "sandmix"?

Dunbar Plumbing
08-14-2008, 03:14 PM
Tell them you want the same mortar they use to build brick walls.

No gravel whatsoever in the mix.

08-14-2008, 04:17 PM
Tell them you want the same mortar they use to build brick walls.

No gravel whatsoever in the mix.

I was just at Home Depot, they have some product that was called something like "Mortar Mix". I think it is used for mortar together bricks, etc. Is this the stuff I would use?

08-14-2008, 05:56 PM
Yep that would be one of the things you can use.

08-15-2008, 07:12 AM
A brick mortar is stickier than a sand mix because it has some lime in it. A sand mix is literally just sand and portland cement (therefore cheaper). A brick mortar would be squishier. A sand mix is much more like wet beach sand...it doesn't squish as easy, and will pack down. You could use either.