Now that we have the electrical and the insulation done in the new tub surround area, it’s time to set the tub in for it’s final resting spot. The tub that we purchased was called a “self leveling” type of installation which mean that if you have a very flat surface for it to sit on, all you would have to do is slide the tub into place, and install the provided stainless steel screws to the framework. Well, wouldn’t that be nice? So what I learned is that there is no self leveling tub in the world that could compensate for the slope that we have going in this bathroom so I had to get a little crafty in the installation.
Luckily there are 6 foam feet on the bottom of the tub that can be shaved to the angle of the floor slope. Since they are about 2-1/2″ thick, you have a lot of distance that you could compensate for. Now, being said, if you decide to go the route that I did by cutting the foam, you can’t rely on the foam to support the weight of the tub on it’s own, you’ll need to support in by other means. This is where we go online an get so confused by all of the “proper” methods to set a tub. You will see all types of ideas from expandable foam, sand, gel, cement, concrete, mortar, and glue. The best solution is to always follow the manufactures instructions but in this case since it was a self leveling system, they didn’t call for any extra support. For this reason, I went with the 50 year old tradition of mortar. It dries hard, doesn’t shrink if you mix it right and it’s really strong.
The purpose of the mortar is to take away any of the air gaps that are going to be in between the bottom of the tub and the sub floor. Since I have made cuts to the foam supports, this will be a very important step to ensure that when we are in the shower that there is no creaking or flex in the tubs bottom.
There are two important things that I learned about using mortar for a tub setting. One is that you want to put down plastic so that the subfloor (OSB) will not suck the moisture out of the mortar prematurely and second, you will want to mix the mortar a little on the dry side so the you don’t have excess water that will cause the mortar to shrink once cured.
Here is the mixture of the mortar being applied where the center of the tub will sit. I made a bunch of small mounds that will be squished once we set and level the tub.
In the image here, you can see the little dance I had to do to get the tub level again once we place it back in its spot. It’s a process of sliding the tub front to back while the mortar spreads out below the tub.
The entire time I am constantly checking for level as I continue to perform the mortar dance. Now that it is level, I will add about 150 pounds of sand bags into the tub and let it dry over night. Yay!!