Hi,

I've recently purchased a showroom floor model of a curved 10 ml glass shower wall and will need to build a curved curb to accommodate it. (There's only one curve, at the end.) Does anyone have any experience or thoughts on how best to build the curb? The only way I can think of accomplishing what I need is to build it 'off site', using 3 2X4's - stacked, glued and cut to the desired angle, then glueing and screwing the entire unit to the wood floor. Does this sound right?

OR

Could I build the curb in place by roughing-in the shape and trying to do the final shaping using mud and wire?

I'm so happy to have found this site - after reading a variety of instructions and seeing the step by step photos provided on how to build a properly sloped, watertight shower pan, I'm feeling confident enough to tackle this project. I think the trick will be to take it one step at a time and not to rush.

thanks for any help and advice.

Jools

Is this actually a curve or an angle?

You may have a hard time building a curve out of 2x4's. Don't think you'd want to try to compensate it out with mud and lathe since it would be too thin in some spots and two thick in others.

Is there a template for the curve? If so, I might get a 2x8 or 2x10, whatever width it takes to make the entire curve, and cut it out with a jigsaw. You could stack them three high and glue and screw them to the subfloor, the adjacent framing, and to each other. Make sure you use kiln-dried lumber.

I have built curved curbs before by laminating bent layers of 3/8 plywood. I cut 2/3 of the way through one face of the plywood at about 1 inch intervals to make it bend better.

If you have access to a band saw, then it's easy to cut the curve out of a 2x12

A better alternative may be to build a solid concrete curb. Form the edges by drawing lines on the floor. Then take a 4.5" strip of 1/2" plywood and screw cleats to it every few inches. Attach the cleats to the floor, bending the plywood to follow the line as you go. Fill with a low water to cement ratio concrete and you're done. A piece of rebar would also help.

There reason many contractors don't do it this way is because it takes a couple of days longer while you wait for the concrete to cure enough to strip the plywood off.

Another good idea, Pete.

If you try this method, I would also suggest that you put some plastic on the floor under the curb to keep the subfloor from drawing the moisture out of the concrete. You might also consider some long screws (maybe 4" or so) screwed in the depth of the subfloor every few inches to anchor it. Otherwise it won't be attached to anything.

Yes K-man has good points. The screws he's talking about are screwed 3/4" into the floor before the pour and protrude into the concrete.

thanks for your responses!

I like the idea of building the solid concrete curb - it would certainly be less complicated than trying to laminate 2X4 (or 6, or 8's) and cutting the angle on a bandsaw or using a jigsaw. This is a definite curve - and it needs to match the piece of 10ml glass that it will be supporting - perfectly. Would the concrete be stable enough to drill holes for the glass support brackets?

Now I'm wondering if we should build the entire shower pan using concrete (poured at the same time)? If so, how would we waterproof it - by using a liquid product?

Concrete would hold the brackets as well as anything else. You'll just need to use a masonry bit. Depending on how long the concrete has dried, you may have to use a hammer drill.

You'll need to decide what method of waterproofing you are going to use before you start the shower. Different methods have different sequences of installation.

However, regardless of the method, you'll need to build that concrete curb first. No way to put the shower floor in without the curb.

Kerdi would be a good choice, but it might be tough for a novice to get that curve waterproofed correctly. You might consider using Kerdi for the floor and 2" up the walls and curb, then use a liquid waterproofing up the walls and for the top and outside of the curb. Make sure you use the Kerdi drain if you go this route.

I was thinking it would be easier to use a liquid waterproofing product for the entire showerpan/curb than to try to cut and seal the curve using a kerdi type of product. Is this a practical choice?

If we go this route and build both the curb and pan with poured concrete - I assumed the 'layering' would go as follows:

plastic barrier
concrete (poured)
liquid sealer
mastic
tile
grout

Have I got this right?

(thanks again for your invaluable insights).

You wouldn't need the plastic barrier if you're going to use a topical waterproofing of any kind. You would need to allow the mud bed to dry for several days before you can apply liquid, which is the reason I suggested Kerdi for the floor.

It's not difficult to put Kerdi on a curved surface the way I was suggesting. You would make a few slits to allow for the curve, then put a single strip along the curve. (Don't know if I explained that adequately) If you have a few days to wait, liquid would work fine.

Keep in mind that most liquids require the use of a fabric and a minimum of two coats with a minimum thickness to be effective. Some installers use three coats on the floor, and also use the Kerdi drain in conjunction with fabric and liquid. It's much more time consuming than a single layer of Kerdi.

And you don't want to use any type of premixed adhesive like mastic. Use a dry powder that is mixed with water. The type you use will depend on what waterproofing you use.

aaahh - thanks -

We are not in a hurry (within reason) to get the project completed, once we start - which is why a few days between steps isn't an issue (this is our guest bathroom).

I'll need to research using a liquid application as I didn't realize it required using a fabric as well - I was thinking it was just painted onto the concrete. Is there a specific type of product to use (material-wise)? btw, why is it necessary?

I was thinking the plastic barrier between the poured concrete and the sub-floor would prevent the floor from drawing moisture from the concrete while it was curing.