Building a shower enclosure

canman47 · Sat Mar 31, 2012 2:18 pm

I'm trying to figure out how to rebuild my shower. It was a tub/shower but it was chipped and I only use it as a shower so I'd like to convert it. I think I've seen the shower pans so hopefully that won't be a problem. It's about 54" long. Don't know how to do the walls though. I've seen those 3 piece kits that you glue in but they always have shelves or something molded into them that won't work with the window I have in the back wall. I would want the back panel to be completely flat which I haven't found. Thought I might be able to make something with this stuff called FRP(fiber reinforced plastic). What do I use as a backing to glue it to? Can't use drywall or cement board due to too much weight and it would reduce the enclosure size enough that the shower pan wouldn't fit. Original install used 1/8" hardboard with stuff we used to call Marlite glued over that. Water got in and the whole thing disintegrated. I thought I would use the hardboard again as a backing and glue FRP over it which I can cut for the window. As long as it's sealed well it seems that would be waterproof. There was never any moisture barrier in the walls or ceiling. Should there be? Anyone have a better idea?

JD · Sat Mar 31, 2012 5:38 pm

I have done this remodel many times, with the window in the tub space. I use 3 piece and 5 piece kits from the home stores. These will be the cheaper style kits and not the nice, rigid wall kits. But there are usually 2-3 to choose from with the flat panels for the sides and back. I like going this way because FRP and marlite panels are only 48" wide. If there is paneling on the wall, I will remove the top 24" or so and replace it with new marlite type tileboard. This gives the area above the shower enclosure a new finished look. I block the joint where the old panel and new tileboard meet and seal it with flashing and caulk. The enclosure kit will end and be sealed somewhere in the middle of the tileboard.

If you are using FRP panels, you will need a trim strip at the 48" mark. I don't care for that at all, but where ever they sell the FRP panels, they will have FRP glue and splines. The glue is applied with a notch trowel.

canman47 · Wed Apr 04, 2012 8:11 am

I'll have to look again at the home supply stores but it seemed to me the shower surrounds they sell are sized wrong for a mobile home. My enclosure is 54x 28 and I think a standard home shower is 60 x 34. Maybe they can be modified to fit? I wouldn't want it extending beyond the shower pan. And what does it attach to? I have bare studs right now. As I said it had 1/8 hardboard before and I'm thinking that's what I should use.

JD · Wed Apr 04, 2012 12:18 pm

Aquaglass, Sterling and ABS all make 3 piece and 5 piece surrounds that use flat panels for the back and side walls, with the soap dish things in the corner pieces. One I use often has a faux tile embossing on the flat panels. These are made for 30" minimum tub depth, as the finished edge does a nice bullnose as a way to end the panel without trim. I just cut the inside edge to match the overlapping edge of the corner piece. Since walls are rarely square, I dry fit everything with masking tape to mark my cuts. With most surrounds, I will add a trim to all edges anyways. Home depot sells this solid plastic trim that is 3/4" x 3" x 8'. I like this trim because I need that 3/4" thickness to close off that triangle gap you end up with in the corners above the surround. I run the trim through a table saw to cut out a recessed area to allow the trim to sit flat against the wall. Nail holes in this plastic is easy to fill and the trim is paintable. The plastic won't rot and is easily cleaned.

Since you are down to bare studs, I would put a vapor barrier against the studs and then nail on the Marlite (hardboard) panels, often sold by the name "Thrifty Panel" and "Tileboard". This will be the backing to the surround. Run the back wall panel horizontally so there is no seam at the 48" mark. The sideways seam will then be behind the plastic surround. Be sure to permanently waterproof this sideways seam. The tub or shower basin will have a nail flange that is about 1/8" thick against the wall. I run vapor barrier down the wall and then over the top of this lip. I cut Marlite wall panels to end just above the tub lip, making a flatter surface for the surround to attach to. Kind of a filler to make the transition over the tub lip smoother. The surround is installed about 1/8" from bottoming out on the edge of the tub, and completely hiding the little piece of vapor barrier sticking out at the bottom. The surround is fastened to marlite panel and the bottom edge sealed with a bath caulk. Doing it this way will keep any leaked water from wicking up the bottom of the marlite panel behind the surround.

One thing to watch for is, if the walls are not square, you can still fit things to look OK, but if there is a bend or bulge in the wall, you will play hell trying to get the surround pieces to fit together. Be sure that the walls are a straight line from the bottom to the top of the surround.

Hope this helps

canman47 · Tue Apr 10, 2012 12:23 am

Thanks JD for the detailed response and I understand most of it. Are you saying that the panels can be cut to the width I need? I went to the web sites for the brands you mentioned and the installation brochures were not helpful about minimum size. They all seemed to be wider than my 28" alcove. I don't see how the seams are made with the 3 piece kits. Do you just run a bead of caulk? And what do you cut it with? Utility knife or shears? Thanks again.

Norm Frechette · Tue Apr 10, 2012 10:42 am

heres some kits that might work

http://www.tilerenew.com/surrounds.shtml

canman47 · Fri Apr 20, 2012 8:28 am

Checked out the link and the minimum side wall is 33.5". Mine is 28". Pretty pricey too for me. They start at $600 plus shipping. This is a shower I rarely use so I want it to be functional but I don't want to spend thousands.

JD · Fri Apr 20, 2012 10:01 am

If you have no extra wall space next to the 27" enclosure, then I think you are stuck using a mobile home bath/shower unit, which is basically what you have. The abs enclosures can be cut with a utility knife. Holes for the faucet can be cut with a regular wood hole saw and drill.

If you want your abs shower/tub base to be truly solid, I would dig out the foam support and use something that is called a "mud set". This is how I install most of my bases. You can get a lot of info on a mud set with a google search, but basically I mix up a couple of 40# bags of motar (kind of dry) and plop it down under the floor part of the base. Be sure to keep your drain hole clear, but you do want to get close. Usually the drain hole is about 9x9 and the mud will just fall down the opening when it squishes out to that area. Before plopping the mud, mark your level lines where the nail flange should be on the wall, then when you drop the pan onto the mud, carefully push the pan down to the line and stop. Give the floor a feel to make sure it is not bulging in the middle and push it down if necessary. At this point, I will usually work on something else or call it a day and finish up the tub later. If you do this early in the morning, you can stand in the tub by afternoon. Read up on this technique before trying it. It is not something you want to do over. (sheet plastic over and under the mud, use std motar, not quick set, etc) Also, this would definitely void any warranty on the mobile home tub/shower, but if the unit is in good shape when you buy it, the warranty is useless anyways. What you end up with is a base that feels as solid as concrete that will eliminate any flex in the pan.

JMO