Bathtub remodel help. - DIY Chatroom

wilson5307 · 09-20-2008, 05:46 AM

I have a quick question that i cant seem to find the answer anywhere. In my master bathroom i have a 5 ft oval drop in bathtub which is also used as a shower. The tub is sitting on granite, is there any way i could pull out the tub, cut the granite into a rectagular shape and use tile or marble for the walls and floor. Basicaly it would be a big tile shower that can also hold water for a tub. My worries are that it might leak or water would soak through grout while taking a bath. thanks.

**thekctermite** · 09-20-2008, 11:03 AM

Nope, won't work. The granite underneath the current tub location isn't made as a shower. That includes sloping the floor toward the drain, as well as a waterproof pan or membrane beneath, which is critical in the process of making a shower floor.

Furthermore, your concern about the water permeating the grout is definately right on. No doubt about it, it will. The granite is also permeable to a small degree. There would be water damage to the floor structure, mold, etc.

You could of course tear out the tub and existing flooring, and we can talk you through the task of building a shower. It is quite a project to undertake, but is certainly possible.

wilson5307 · 09-20-2008, 09:31 PM

Thanks for the reply, here is two picutes to better explain myself. I agree with you, but i saw this on tv and took a picture because it is what i would like to do. The drop in pic is my bathtub and the second one is what i got off tv. My problem now is when i take a shower water goes everywere since it is a drop in tub with a 2 inch lip the water has know were to go. so i had to get a oval shower curtain, which i hate because it sticks to you when you shower. Im trying to keep the bath part for my wife, I would love just one big shower but she say she cant live without a bath. thanks a lot.

wilson5307 · 10-10-2008, 12:42 AM

bump! any ideas.

wilson5307 · 11-06-2009, 11:18 AM

bump again.

Blondesense · 11-07-2009, 02:34 PM

With a shower above a tub you need everything to slope towards the drain. This includes the granite that the tub currently sits on.

I don't see the significant difference between the two except the second one looks a lot less comfortable. I don't see any evidence of a shower in the second picture. It looks like a tub only. They will both have water collecting on that horizontal surface and against the wall which is asking for water damage, rot, and mold. Not good. So the bottom line is even if you could somehow cut the granite and properly build a tub you would still need the same round shower curtain.

Tear it out, do it right, and make sure it is properly waterproofed as a shower.

.

Blondesense · 11-08-2009, 05:41 AM

After re-reading my first post it sounded a little harsh. Let me try this again.

I'm no expert myself, but I'll pass along what I have learned reading these forums researching a shower project of my own.

A tiled shower is built quite differently than a surround for a showerless tub, even if they both use the same tiles. I assume your tub did not originally have a shower and that it was added later.

Because of the amount of water in a shower, shower walls usually are built with cement board, along with a waterproofing layer underneath the tiles. This is to be sure absolutely no water will get through to cause damage or give mold a chance to start.

A showerless tub, on the other hand, is different. With just a tub, you expect an occasional splash at most and so the surround is seldom waterproofed in the same way as a shower. Often greenboard is used behind the tiles in a tub surround , or even just drywall. Neither is waterproof. Greenboard is water resistant, but if water penetrates that surface, it will absorb water and mold. Even without a tub lip like yours, standing water on a horizontal surface makes the corners especially susceptible to water penetration. Caulk alone is not enough to protect this area. Windows are also a weak area.

You may get away with adding a shower in a tub surround for awhile, but it will fail eventually. Even if tiles are waterproof, the grout isn't. People often don't realize there is a problem until tiles become loose or start dropping off, by which time there is major damage.

So, even if you could properly build and waterproof the tub (no small task), to protect the walls from water damage you either need to start from scratch and waterproof underneath, or use the old shower curtain.

Best/easiest solution is probably to take the whole thing out, install a tub made to be used with a shower, and make sure everything is totally waterproofed.

wilson5307 · 11-09-2009, 01:38 PM

I appreciate you taking your time to post, I think you correct in that the granite will just absorb the water like a sponge. I know the picture doesnt really show that it is a shower but if you look on the wall you can see the valve. After more research and talking to a couple builders i have decided to rip out the tub and granite and build rectangular tub out of cinder blocks then seal it with a shower pan type material and then tile it with mozaic glass tiles then seal the grout with water seal. After that I will put in a glass door to eliminate water splashing. Trust me I would love to do just big shower but since this is the master bath I need it to be more functional with a bath and shower for re-sale value.

Blondesense · 11-09-2009, 03:44 PM

Quote:

Originally Posted by wilson5307

I know the picture doesnt really show that it is a shower but if you look on the wall you can see the valve.

I noticed the shower control on the wall. Is the control on the wall the same style and manufacturer as the spout in the tub? It is hard to tell in the picture but they don't look quite the same to me. Most likely a previous owner who, like you, wanted a shower added it later. Either way, the garden tub with the lip shows that your walls are not built for shower use.

Are you planning on re-doing the walls also? I would suggest doing a lot of research on waterproofing especially the window and any horizontal surfaces. You will be at risk for water damage and mold down the road if you leave them as is.

Last year I noticed one tiny little 2 inch tile loose on my bathroom floor. By the time all was said and done, I had to pull the toilet and tear out a three foot section of the floor down to the joists to repair the water damage. All due to a tiny leak in the toilet. A similar leak in a shower or tub can mean tearing up your entire bathroom. It is very important to get the waterproofing right the first time.

Do not underestimate the amount of damage water can do in a bathroom. Especially since it is usually remains well hidden until major damage is done.