Mortar under molded shower pan

Old 10-23-03, 09:06 AM
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Mortar under molded shower pan

Instructions with my Swanstone molded shower pan suggest setting it in mortar ("Quikrete") for maximum stability. 1) Is this necessary? The pan (34x48") seems to be acceptably thick, and has ribs underneath. 2) Would I put the mortar directly onto the 3/4" plywood subfloor or first tack down 15 lb. felt? 3) Do I just shovel out a layer and push the pan into it, or is there a method/trick?

Thanks for any advice!
Old 10-23-03, 09:32 AM
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Following the directions per the manufacture for installation. Lack of support causes squeaks, in some cases leaks at drain pipe fittings and worst of all cracks in the finish material. Most manufacturers recommend or suggest installing a mortar base support under it before setting the tub or shower unit in place. You can use either a bag of Quikcrete or a 5 gallon pail of pre-mix joint compound. ( usually I use the pre-mix 5 gallon...lazy and it's less mess) You can lay poly down under the tub or shower prior to doing this to prevent any moisture issues while this is drying.

When this sets up, usually with 24-48 hours, your tub or shower bottom will be rock solid supported. This does 2 things, prevents any possibility of potential cracking within the fiberglass/acrylic and eliminates any movement at the tub/shower drain assembly or potential leaks that could happen.

Ensure that you do not get any around the tub or shower drain assembly should you need to do anything down the line. In most cases, the holes cut for the drain lines will keep any base support away from it.

Hope this helps!

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