Who's got tips for a first time tiler?

[ohiobrewtus]

After just reading through this thread I thought I'd chime in. Bradsul is right. The best advice would be to put a subfloor down to ensure a level surface (among other things). But when you DIY there's not always money in the budget to do things like that.

I have tiled directly onto concrete floors before and had no problems after 3 years when I sold the house that I did the work in. I actually had more problems with a burber carpet that I glued directly to a concrete floor than I did with the tile.

 

[bradsul]

Still believe everyone's overthinking the moisture issue. I tiled my shower walls with 18" tiles using your basic gray thinset and regular grout. Doesn't get much more damp than that .

I hope you at least used concrete board behind that. If you ever take that shower apart I suggest wearing a respirator or at least a face mask.

 

[Bobby_M]

Yeah, it's not about the moisture making the thinset fail. It's not water soluable when it's set since it's basically concrete without the aggregate. It's about coming up into you nice new living space and creating mold issues both in the grout and everywhere else. People usually live with the moisture in an unfinished basement. It's a problem when you start hanging drywall and putting furniture in there.

 

[user 574]

I hope you at least used concrete board behind that. If you ever take that shower apart I suggest wearing a respirator or at least a face mask.

Yep on the concrete board. If I have my way it'll never be taken apart but that's assuming SWMBO the interior designer won't get bored with it 5 or so years down the road .

Understand Bobby... That's what I started thinking about after my post. I vaguely remember humidity

 

[CrazyToad]

Installing a wood subfloor on a concrete slab is not needed, and is very expensive when ceramic tile is considered. Just a brief history lesson with tiling in the US, tiles were traditionally installed on a concrete slab. If any of you have those old, white, hexagon mosaic tiles in your bathroom, odds are they are installed on about 4" of concrete. In your situation, I wouldn't really worry about the moisture problem, as thinset and tile will not be damaged by moisture. Mold is an issue, but if you seal properly with a high quality sealer, it won't be a problem. Use this sealer, available at the depot (here).

The biggest problem I would worry about is potential cracking. It is not that big of an issue considering you are installing on a slab, but it is still something to take into consideration. If you are that concerned about it though, use Ditra. It is a great underlay that will separate your tile from your substrate. If your substrate moves, your tile will not, and therefore prevent cracking.

In my professional opinion, feel free to tile directly onto the concrete slab. Use a modified thinset like this. It will bond much stronger than normal thinset.

 

[cubbies]

Yeah, that is the decision I made. We are not going directly onto the concrete, we are using a "membrane" kind of like that flexbond. Except it is more of a mortar kind of consistency, it is kind of hard to explain. Basically you flat trowel it over the whole area and it leaves a very thin layer of material between your mortar and your concrete. My buddy works on floors commercially for a living and he says they do this stuff all the time. It will keep the moisture out and will help against cracking. He said it is not very likely my tiles will crack.

We prepped the area last night. Pulled up the carpet, took off the tack strips, removed the baseboards and spread the membrane. Friday we start laying tile!

 

[CrazyToad]

Yeah, that is the decision I made. We are not going directly onto the concrete, we are using a "membrane" kind of like that flexbond. Except it is more of a mortar kind of consistency, it is kind of hard to explain. Basically you flat trowel it over the whole area and it leaves a very thin layer of material between your mortar and your concrete. My buddy works on floors commercially for a living and he says they do this stuff all the time. It will keep the moisture out and will help against cracking. He said it is not very likely my tiles will crack.

We prepped the area last night. Pulled up the carpet, took off the tack strips, removed the baseboards and spread the membrane. Friday we start laying tile!

Flexbond is mortar. You are talking about a product like Red Guard correct? It is a liquid, kind of looks like slime. When it dries, it will be like a laytex layer on your concrete. Be careful when speading your thinset on that stuff, it can tear. Good luck. I hope everything comes out well for you.

 

[cubbies]

Well, the stuff I used was not flexbond, but I guess it was similar. It is like a mortar. it is dry and you mix it with water and flat trowel it on. When it dries, it looks kind of like cement. I am pretty confident it will all work out. My buddy has been doing this stuff for a while, and he is not worried about it.