Thread: Shower base Install

Does any body have a reference/ install specs on a fiberglass base?

New home customers base is not secure at floor, moves apx 1/2".
I've been writing it up as needing correction to prevent cracking from movement.

The builder used to correct this, by cutting drywall and spraying foam under the base, or drilling a hole in base, and filling hollow areas, then patch the hole, now the same builder is saying it's OK, no correction needed.

Similar Threads:

• Shower stall floor
• needed a breeze in the shower
• Window in combo bath/shower area
• Flow restrictors affect shower temps - Chicago Daily Herald
• Trained Chimpanzees Install Flue Pipe

Can't site a code but I'd think any of the manufacturer's specs would require it.

As a side note - the foam to support the base works well. My slight frame (250lbs.) was too much for our shower and broke the drain pipe shortly after we moved in. I was skeptical when I was told to spray the foam in there. I never thought it would hold. It's been about 2 years and the floor of the shower feels like cement.

Originally Posted by Dan Harris

Does any body have a reference/ install specs on a fiberglass base?

Here is one: http://www.lascobathware.com/installation/2900.pdf

Read note d. at Pre-installation Requirements.
"d. Use of casting plaster/plaster of paris (foundation material) is mandatory for all construction applications (i.e. hotels, motels, dormitories, health clubs, residential homes, apartments, etc.)."

Also note Bottom support: under Installation, 7th bullet down.

I am guessing that if it rocks back and forth, that it is setting on the drain hub, and that could cause the pan to crack through around the drain hub.

Some of the manufacturers installation instructions that I have read recommend, but do not require additional support methods. I guess it all falls back on installation instructions. Here's another set: http://www.jacuzzi.com/pdf/SHOWERBASES.PDF

Brandon,

If the shower pan base is wobbly, you know it is not installed in accordance with those instructions.

Then it becomes a 'What is the recommended correction by the manufacturer.'

Over the last couple months I've seen fiberglass jacuzzi tubs mounted on loose 2X4s and another one on what looked like drywall mud.

Kind of scary those are the ones with an access panel that we can see. Imagine what gets covered up beneath the showers and tubs that we can't see.

That shower base should be anchored in some way. Typically roofing nails are used at each surrounding stud and are nailed in so they come down over the top flange of the base. I always drilled the top flange at each stud and used screws to anchor the bases I installed. In situations where the floor is really out of plumb, I have used a bed of concrete under the base to help level and support it. The foam will probably work, but seems to me to be the do-it-yourselfer way to correct the problem.

Originally Posted by Matt Fellman

Over the last couple months I've seen fiberglass jacuzzi tubs mounted on loose 2X4s and another one on what looked like drywall mud.

Kind of scary those are the ones with an access panel that we can see. Imagine what gets covered up beneath the showers and tubs that we can't see.

I have seen bags of drywall mud used for the base many times. 6 bags of drywall mud makes a great base for a hydro tub!

Originally Posted by R. A. Wilkins

That shower base should be anchored in some way. Typically roofing nails are used at each surrounding stud and are nailed in so they come down over the top flange of the base. I always drilled the top flange at each stud and used screws to anchor the bases I installed. In situations where the floor is really out of plumb, I have used a bed of concrete under the base to help level and support it. The foam will probably work, but seems to me to be the do-it-yourselfer way to correct the problem.

I installed a tub recently from a brand I hadn't used before. Whereas MOST fiberglass tubs I've put in have a piece of plywood embedded into the fiberglass to add support to the acryllic, this one did not. The tub was coated in fiberglass, and which had some built-in legs to level the bottom, and THEN there was a piece of plywood underneath that. But there was no support on the base of the tub at all, beyond the fiberglass. It was VERY spongy when you got in it. I called the manufacturer and their recommendation was actually to use expanding foam underneath it. It actually worked great, the bottom of the tub is solid now. I still think that's a very crappy way to design a tub though.

Also, I ended up using TOO much foam, and it lifted the tub out of the hole a half an inch. I had to pull the tub up and re-do the mortar bed. But after that it worked great.

Originally Posted by Joshua Hardesty

Also, I ended up using TOO much foam, and it lifted the tub out of the hole a half an inch. I had to pull the tub up and re-do the mortar bed. But after that it worked great.

That is a risk with using expanding foam, even low expanding foam, in that the expanding foam may not only push the unit up from its intended position, but the expanding foam would also bow the bottom of the tub/shower up in the middle, causing the tub/shower not to drain properly.

I called the Lasco 800#
Per them it is an installation problem, and needs corrected.

I had a simular inspection on a tub.
His builder also stated to him it was not a problem.
Talked to the customer a fews months latter, sure enough it was a problem.
Come to find out it was resting on a piece of sharp concrete, [I'm assuming a piece from when they broke out for the drain] a few weeks after the inspection the sharp edge of a piece concrete broke thru the bottom.

This no problem, thats normal , one ended up as a three day, couple thousand $ cost of tear out and install new tub, CM shower walls.

Moral of the story in my book . Don't take the word from someone who has to pay to correct it.

Am I the only inspector that has stepped through a brand new tub floor. About a year ago I had a new home inspection, and the floor felt soft. I shifted my weight and sure enough fell through to the subfloor. I expected the builder to contact me, and somehow blame me for breaking the tub........... never heard anything after the inspection.