Waterproofing niche

[dschwake]

Hello everyone ,

Thanks for a great forum, been lurking for a while, this is my first post.

Building a shower, Redgard over Durarock substrate. After getting all the prep work done, we decided to add a niche. I've been reading up, seems pretty important to get that niche waterproofed with the horizontal surfaces & all. Seems Kerdi or the like membrane is most popular for waterproofing, is it acceptable to waterproof a niche using Redgard? Saw a video on YouTube of a guy using some blue stuff to waterproof a niche and he recommend not using Redgard because it was not as thick as the blue stuff.

Pic. of my niche attached, thanks in advance.

[Davy]

Sure you can. I would go ahead and tape and thinset the joints first and then apply two coats.

[Tool Guy - Kg]

Welcome, Scott.

...And make sure you've got a slope to the bottom of that niche.

By the way, RedGard has improved since their last reformulation a few years ago. I wouldn't hesitate for a second to use it. But go out of your way to get it to proper thickness. A super common problem with any paint on membrane that's applied with a brush or roller is applying it much, much, much thinner than the directions call for.

[jcsa]

Scott,
Just like Davy said i would thinset and tape your inside and outside corners. After it dries then apply two coats of Redgard. The one thing we do is also use the reenforcing tape with the Redgard also. Just helps the strength of it for future movement. My two centavos john cox

[dschwake]

I used that alkali-resistant mesh tape set in thinset on the inside corners of the shower, can I use that same tape on the outside corners of the niche? I saw a roll of 5" wide Kerdi Band waterproof membrane at Depot, would it be better to use that to waterproof the corners of the niche? I guess I would still need to Redgard the back of the niche since it's 12" wide, can you put Redgard over Kerdi or vice versa?

[cx]

Scott, if you've properly treated your CBU corners you can properly apply your RedGard waterproofing membrane to that area and be in good shape.

While it's probably feasible to put RedGard over Kerdi, I wouldn't recommend you try that in your application.

My opinion; worth price charged.

[dschwake]

I am attempting a niche in my first tile shower project, getting ready to prepare the niche for a couple shelves. I'm thinking about some type of solid surface for the shelves, and came up with the idea on the attached sketch and thought it would be a good idea it vet it here with the experts before attempting this.

Thanks for your input.

[cx]

Why would you not just support your shelves on the tiles on the sides of your niche, Scott?

[Kman]

I do mine the way CX describes. Either cut the top of each support at a slight angle (about 1/16") so the shelf will slope down at the front, or use something to prop up the back of the shelf very slightly.

When it's grouted in, the shelf won't move at all.

Are you planning to use bullnose for the shelf?

[Houston Remodeler]

OR

Use 100% silicone around the side. Wedge the shelf into place using these glass wedges, which get cut flush, then a bead of silicone is applied around the 3 edges

[DT DIYer]

Hey Kman, a quick question for you. Does your way of installing shelves apply to granite shelving as well?

[Kman]

Yes. Anything that is rigid enough to support it's own weight, plus whatever you plan to set on it. I often notch the tile on the back of the niche for even better support.

[dschwake]

Originally Posted by cx

Why would you not just support your shelves on the tiles on the sides of your niche, Scott?

Not sure of preferred shelf material yet and I want to keep tiling, thought it would be a good way to drain water off the shelf on all sides without sloping it, and if the shelf were to break (thinking glass) it would be easier to replace. It will primarily be the kids bathroom and they are capable of breaking anything. Boss says no to bullnose tile for the shelf.

Those glass wedges in Houston's post look interesting, where do you get something like that, and how do you cut them flush?

[cx]

You can get the glass spacers from any glass company. They come in a variety of sizes and thicknesses. Trim them flush with a razor blade or just cut them to the correct size before inserting.

[Kman]

You'll want to get tempered glass for that application.