Hi all,

Im a complete novice when it comes to tiling so i hope im not being too stupid.
Im about to start tiling my new kitchen floor using 450 x 750 porcelin tiles. Ive an area of about 30m2 to tile and its onto a concrete screed with under floor heating. Just wondering what adhesive i should use?/what thickness it should be applied?/should it be applied onto the tile,the floor or both? and how long i should not use the under floor heating for after tiling? (i think somebody said a month, maybe the underfloor heating company, is this correct??). Also should i buy ready mixed adhesive or not?

Thanks

Pete.

Hi Pete and welcome.. quite a task for a first job..

Are yo using a matt system or loose cable..? do you intend to insulate the floor to prevent heat loss and extreme running costs for UFH..?

Hi Dave,

The Underfloor heating is aready in the screed. Its a wet system and yes i did use insulation espeicially for floors. Sorry didnt make that clear in the post.

Pete.

You will need to ( in my humble opinion ) lay a decoupling membrane to tile to once the screed has cured, ( unless using a green screed adhesive ) how long has it been down, has the heating been commissioned, slowly up and then down, in any case, a good flexible rapid set adhesive to fix the membrane and then tile to membrane

EDIT just re-read your post, if it's your first job, it is a project and maybe go with a standard set adhesive for longer working time, have you thought about getting a pro in, those tiles aren't easy by any stretch of the imagination.

Concrete screed-how long has it been down over the UFH?

I always use flexi-powder adhesive with porcelian. Plus flexi grout.

Apply to the floor-follow the makers recommandation if the floor needs sealing with that particuliar adhesive. If the tile-in this case polcelian has indents in the base, skim with adhesive as well. It all depends if the floor is very level to which depth trowel you use.

As to the UFH, and in that case the adhesive, follow the makers instructions as to when or how you turn it on.

Oh yes, not bucket-ready mixed gear.

Sounds like, IMO, you need a professional tiler to do this job.

Hi Alan and Fred,
The screed has been down for about two months now. I have tiled my bathroom with large-ish tiles 300 x 300, which went quite well a couple of years ago, so ive a tiny tiny bit of experience! I have thought about getting in a pro but trying to save money plus i have my father in-law helping me who is quite an experianced diy-er. Would you say large tiles are more difficult to lay than small then?

Thanks

Pete.

Hi Pete. These tiles are very difficult to get flat and level if you're not experienced....especially if laying 1/2 or 3/4 bond. If not 100% level where the tile meets the middle of the tile on the next row you will have problems with lippage so make sure your spirit level is used at all times. Run you level across the whole floor before you start tiling to see if there is any dips in the substrate and I would recommend to use self levelling compound to get over this if there is. The trowel size a basic rule is to use a size the thickness of the tile but on this installation I would go a little deeper.

I think it is essential to get the initial setting out spot on and find problems before they occur. Apart from deciding on the line of the tiling to square the room if necessary/possible and avoid small cuts at walls etc. I have always placed a row of double thick tiles on the middle run and the same at points on the outside wall. Using a straight edge I have checked for general level and also dipped from the straight edge to pick up any high spots I need to overcome or low spots that might need self levelling. I am sure that the professionals on here can advise more on that score though .

Thanks for all the advice so far guys.
So just to recap then.
1. Pay particular attention to preparation of screed, level/seal etc.
2. I should use flexible adhesive. (not pre-mixed).
3. Adhesive thickness = A bit thicker than the tile + a skim on the back of the tile.
4. Be very accurate when leveling tiles!!!

Oh and another question is where is the best place to buy adhesive?

Thanks

Pete.

Tile Giant..