Tilies on shower base over fiberglass


  #1  
Old 09-01-04, 11:10 PM
barlse
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Question Tiles on shower base over fiberglass

I've built a shower stall and I didn't want to use concrete for the shower floor, I decided to build the shower floor out of molded fiberglass. (pre-fab shower bases sold by Home Depot and elsewhere won't fit the size of this shower)

At any rate, I setout to buid a mold out of 3/4 inch plywood for the fiberglass. I'm finished with the mold, but this mold turned out to be so prefect that I now would like to tile the mold and use this mold as a shower base. The mold is strong and perfectly tapered towards the center for the water to drain smoothly.

My problem is that I woud like to make this floor base totally waterproof before I do the installation of the tiles and I don't want to use fiberglass anymore as a laminate (too messy). Is there anything that I could use to waterproof the floor base with, something that would last without any water leakage before I install the tiles?
 

Last edited by barlse; 09-01-04 at 11:21 PM. Reason: spelling
  #2  
Old 09-04-04, 11:04 AM
floorman
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You could look into elastomeric membranes and see what they do for wood,e.c.g ,mapei are a couple that come to mind.Never done one over a wood base before so i can't comment on the do,s and don'ts of this type of install,however i am very interested in the way this turns out so if you would'nt mind please post back and let us know how this turns out good or bad.

I think this is a good idea you have going here and if the base is as strudy as you say then you have a good chance of this succeeding if you figure out how to do the corners of the base and make them water tight then you have a good chance of success.

Just curious though how did you get the slope?

A few after thoughts here,consider maybe a metal or other sort of pan underneath for added insurance and also use epoxy grout on the floor,laticrete has a new one called spectraloc great product very user friendly
 

Last edited by floorman; 09-04-04 at 11:18 AM.
  #3  
Old 09-05-04, 07:08 PM
barlse
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mold construction

Thank you "Floorman" for your great suggestions, "You could look into elastomeric membranes and see what they do for wood,e.c.g ,mapei are a couple that come to mind.Never done one over a wood base before so i can't comment on the do,s and don'ts of this type of install,however i am very interested in the way this turns out so if you would'nt mind please post back and let us know how this turns out good or bad"

I'll try to explain how this mold was built. (difficult without the benefit of a picture, but I'll try)

1. I laid down the normal sub-flooring of' 2" x 8" planks and setup the normal installation of the 3" PVC pipes for toilet, lavatory and shower drains.

2. Mold construction: I started by building a rectangular frame (call this frame the "inner frame" ) approx. 2' by 4' in dimension - using 2" x 3" wood planks- to fit the surrounding walls of the shower stall.

3. Inside this frame, I placed 2" by 3" cut lengths of wood to form 2 Ts (now, imagine 1 T placed to the left inside of the frame and the other T on the right side of the frame in the same fashion - I left enough space between the 2 Ts to accommodate the drain pipe and flange of the shower drain.

4. I then used cut lengths of 2' x 4' inexpensive pine wood to surround the outside of the entire frame (using 3/4" x 6" pieces of wood) the sides of this second frame (outer frame) stick out of the inner frame approx. 3 1/2 inches to form walls around the entire inner frame.

5. I used 3/4" plywood (approx. 2' x 4' ) to fit inside the frame and to cover the entire frame as a floor to the structure (this 3/4" plywood sits on top of the inner frame, so now you have approx. 2' x 4' floor surrounded by the outer frame of 3/4" x 6" frame with a little wall of approx. 3 1/2" in height around the floor. ( I left approx. 3/32 of an inch leeway on all sides of the entire structure for ease of installation - a bit smaller than the actual size of the shower space and surrounding walls which is 2' x 4')

6. I then drilled a hole about 2" in diameter to accommodate the shower drain pipe in the center of the 3/4 inch plywood floor). Then, I cut the 3/4" plywood floor of the structure in quarters, (2 cuts through the center, to divide the floor into four equal parts with the drain hole in the center)

7. I then place shims about 5 shims (one on top of the other) on each of the corners of the "inner frame" so when I placed the four parts of the 3/4" plywood floor back in place and on top of the "inner frame" so it would form a slope and taper towards the center h2" hole of the drain pipe. I glued the shims (no screws) to the "inner frame" with "Elmer's Carpenter Glue" which is made with resins and form a strong bond. I then any spaced below the 3/4" plywood d floor with additional shims as best I could always using this glue. I also glued 2 shims underneath the edges of the center cuts of the four parts of 3/4 inch plywood so it would also slope towards the center .

8. I then used 1 5/8" drywall screws to fix the entire 3/4" plywood floor to the structure.

9. By this time I had a perfectly sloping shower floor with four adjoing cuts running the entire lenght and entire width of the 3/4 inch plywood shower floor.

10. In order to seal, to cover and to make the sloping cuts (lines) smooth all the way down the center of 3/4 inch plywood floor I used "Elmer's" wood putty, I molded the putty to round these lines (leading towards the shower drain hole) I also sealed around all edges of the floor with this wood putty. (This putty hardens to a consistency harder and tougher then the wood itself and forms a perfect bond) Its not difficult to mold and to form curving slopes; if you smooth it out with plastic spatulas you don't even have to do any sanding. You can easily do the curves around the corners and around the sharp edges where the floor meets the 3 inch walls of the structure.

I then applied a light coat of putty mixed with a little bit of water to the consistency of thick mayonnaise and using the spatula I applied this soft putty to the entire floor in order to seal the surface of the floor to a limited extent. However, once I had the floor looking and sloping the way I wanted I used a drywall electric sander with a 220 grid sandpaper and lightly sanded the entire surface. "Light sanding" are "key words", do not over-sand because you could create valleys where water could accumulate.

At this point you can test the floor structure with some water poured from a glass on all sides to be certain that the water runs towards the drain hole. (do not ue a lot of water or running water) Since I was "experimenting" with this type of work it took me about a full week to complete. But, if I had to do it all over again knowing all the steps as I do now, it would only take me about 2 - 3 days to do this entire work. You have to allow drying time for the glue and putty.

(The actual size of my shower stall is 24" by 42" (not 4 feet as described above, I only used 2' x 4' description for ease of explanation and I also placed the drain hole off center and closer to the shower head about 6 inches off center. With this type of structure you can plac the drain hole almost anywhere and then adjust the cuts of the plywood and the lengths of the Ts accordingly)

If everything works out, I think it will be worh it, rather than pouring 480 pounds of concrete to a 3 or 4 inch thickness. For one thing, if I ever have any problems it will be a lot easier to remove the floor fix the plumbing or any leaks and put the whole thing back together again.
 
  #4  
Old 09-05-04, 08:36 PM
barlse
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ELMER'S WOOD FILLER and other details

For the construction of this mold I used ELMER'S WOOD FILLER not Elmer's Wood Putty. I also carved out about a 1/4" deep into the 3/4 plywood floor around the 2' drain hole and the size of the diameter of drain flange in order to recess the flange and make it flush with the floor.
 
  #5  
Old 09-05-04, 11:19 PM
barlse
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Question Waterproofing

Home Depot sells a Neoprene liner membrane which is what some people are using as a liner before they pour the concrete for a shower base. They also sell to glue to attach this type material to floors, wood, etc.

Do you think that glueing this neoprene liner to my structure (it would definitely make it totally waterproof) but, is it a good medium to install the tiles over it? Is this one of the elastomeric membranes that you are talking about?
 
  #6  
Old 09-06-04, 06:39 AM
floorman
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You certainly have a lot of pateince my friend.No,those liner are the p.v.c. type and just lay there floating,the ones i am refering to you would prime the base with a latex primer and then lay the membrane into the primer after peeling off the the protective film on it,like peel and stick,very sticky stuff so if you touch it to itself after peeling it off you might as well throw it away and start over.

You can get this stuff at any flooring supply place not the box stores.Find a distributor in the area and call them they will know what you are talking about.

Something else to consider as well here,you may be able to get a paint on membrane to do this job too h.d has one from custom floor products called red guard you can look at the specs of that and see what it says.If you go to a distributor you can get something called blue 92 that was out first and probably the better of the 2 .

Good stuff sounds like you did a good job on the base,a little time consuming but it may just work.One question though was this exterior grade plywood that you used?

Please let us know how this comes out and post back if we can add some more to this
 
  #7  
Old 09-07-04, 09:46 PM
barlse
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Update, corrections and other details

I wasn't sure about the grade of the plywood, so I went back to Home Depot to find out, and lucky for me, they told me that all plywood they sell at HD in my town is for exterior use, therefore I used the right grade. Thanks again "Floorman". Good piece of information.

Correction to my posting "Mold Construction"; two corrections noted "4 shims" and "filled"

7. I then place shims about "4 shims" (one on top of the other) (not 5 shims as I said before) on each of the corners of the "inner frame" and in a way resembling a square rule -four shims going one way and 4 shims going the other way at each corner , the placement of the shims elevate each corner about 1 1/2 inches, so when I placed the four parts of the 3/4" plywood floor back in place and on top of the "inner frame" so it would form a slope and taper towards the center 2" hole of the drain pipe. I glued the shims (no screws) to the "inner frame" with "Elmer's Carpenter Glue" which is made with resins and form a strong bond. I then "filled" any spaces below the 3/4" plywood d floor with additional shims as best I could always using this glue. I also glued 2 shims underneath the edges of the center cuts of the four parts of 3/4 inch plywood so it would also slope towards the center.

Since my last post, I've done some research, I looked into roofing, swim pool and basement waterproofing materials, most of the best materials available in the market for waterproofing are the Elastomeric membranes as suggested by "Floorman" (some are easier to apply than others) the problem is that most of these materials are sold in 60 foot rolls. Boy, thats a lot of material for a small job.

At any rate, I've also looked into the possibilities of fiberglass and I found out in phone conversations with suppliers and manufacturers of fiberglass products some good news and some bad news, I hope that this type of infomration will answer some questions about placing tiles over fiberglass.

1. Bad news first. Pre-fab and free standing shower bases like the ones sold by HD and other suppliers can not be tiled due to the slight up and down movement of the fiberglass base when people step into the shower. I guess that most people know this already. These pre-fab shower bases last for years, but will show hairline cracks overtime, needing replacement and very difficult to do the tiles because they have no solid support underneath to prevent any movement.

2. Good news. If you contruct a wood mold as I explained in my previous posting and laminate the wood with a couple of layers (I say) of fiberglass or just one layer (they say) of fiberglass. -all fiberglass suppliers and manufacturers I spoke with say one layer is enough- will make the shower base totally waterproof and you then sand the surface with 80 grid sandpaper (inexpensive orbital sander a/k/a/ random orbit sander is best for the job (HD sells the sander RYOBI for just under $50.00 then you can tile the fiberglass floor to your satisfaction. This will last a lifetime.

3. While laminating the wood with fiberglass is probably the best course of action, you could also mold the fiberglass shower base with the same mold as above, then remove the finished fiberglass shower base product from the mold; for this you need about 5 layers of fiberglass, then install the mold as a solid base and support and place the fibeglass shower base on top which is now fully supported by the wooden base/mold. Do the sanding with the 80 grid sandpaper and orbital sander and then tile the floor to your satisfaction. Do not over-sand, just enough to create a rough surface in all cases. This will last a lifetime. This is more time consuming and the benefits that I can see is that you have two separate parts to do the installation, plus if you ever have a problem with the fiberglass shower base you can still use the same mold to create another one and you will be able to remove the top only and check any future problems without having to remove the entire shower floor. In order to remove the finished fiberglass product from the mold you need to cover the mold in gels (professional way) or cover the mold with duct tape (homemade approach) making sure that you place the strips of duct tape flat and straight, without flaws and make sure that no wood is exposed, all wood must be covered with duct tape. The duct tape acts as a releasing agent. The duct tape thing is recommended by people over the internet who work with fiberglass, is called the "poor man's gel" according to some people, but it works fine. I've never done this before or worked with fiberglass.

At this point, I'm more inclined to finish the job with the laminating technique as explained in (2.) of this posting. Also you have two choices by laminating with "fibeglass cloth" you hardly need to do any sanding for a finished fibeglass floor (just paint it with enamel paint or, better, an epoxy based paint, but you have to do the sanding if you are going to tile your shower base floor.

I'll keep posting my progress, success, failures, trials and errors as I continue with this work. Good luck to all and to me!
 
 

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