Laying Floor Tiles

[sam8364]

Hi everyone,

I need to lay floor tiles on a new concrete floor and I am not sure how to go about preparing the surface.

I am laying ceremic floor tiles - they are fairly cheap and fairly thin affairs.

The surface is a new concrete slab which has had an inch or more of sand and cememt screed laid on top. The screed has been down a couple of weeks and in the hot weather appears to have got off - certianly the surface dried within 24 hours.

The current surface is pretty flat - can I lay the tiles directly on this?
Do I need to seal it with anything first - if so what?
Do I need to put a self-leveling product down as well - if so what is best and how long before i can lay the tiles?

Thanks for any advice!

 

[gcol]

The current surface is pretty flat - can I lay the tiles directly on this?
If by "pretty flat" you mean you can put a straight piece of wood about a metre long and see no more than a couple of mm variation in height, then yes, you can tile onto that.

Do I need to seal it with anything first - if so what?
You shouldn't need to. Read the instructions on the adhesive (powdered, not pre-mixed). Ensure the surface is clean and not dusty - mop before hand.

Do I need to put a self-leveling product down as well - if so what is best and how long before i can lay the tiles?
See first question.

 

[sam8364]

Cheers gcol -

Pretty flat means no more than a couple of mm except one small area where it is nearer 4mm-ish - will the tile adhesive take up this amount of gap?

If I do not for self-leveling screed- is there a particular one people recommend and how long before you can walk/tile on the surface.

 

[gcol]

4mm - You'll get away with that.

Febflor Plus is ok - costs me about £11 a bag (don't get it from B&Q cause it's £20 there). You can cover that after 8 hrs.

 

[Andy-D]

You could also use BAL's PTB adhesive (pourable thick bed). Its good for filling dips in floors and will go up to 25mm i think. Also as you mix it up to a "pourable" mix it will ensure that you get a 100% bed for your tiles which you will require if they are thin.