Tiling Question

Why have my porcelane tiles lifled.i had 24"x24" porcelane tiles fitted with under floor heating onto a wooden floor

quick set addhesive was used and I waited three days before gradualy building up the heating, the tiler used dob and dab method instesd of using a notched spreader could this have been the problem, the addhesive has not adhered to the tile at all

10 Answers

Best Answer

The tiler should have laid these on a full bed of adhesive, with appropiate notched trowel.
Probably best you get someone else who knows what they are doing, as he obviously doesnt, just dotting them down, get them to check the boards are well screwed down beforehand.


Answered 4th Jul 2011

you dont dot and dab floor tiles { or wall tiles} they need to be layed on a flat bed of adhesive ..if the tile is not fully supported will just crack or pop up {as yours have done } you state TILER used dot and dab ..sorry but he is not a TILER if he used dot and dab ...


Answered 5th Jul 2011

all the answers are right except the dot and dab one ,never dot and dab,why do people still think its ok to do this,ITS NOT,if your tiler does use this method dont pay him,coz your gonna have to call another tiler out in the future.Hope this helps.


Answered 13th Aug 2014

the best way ive found is to screed over under floor heating with flexible latex, then stick tiles down with flexible adhesive using 10mm notched trowel then grout with flexible grout never had a problem yet. ps was floor ply wooded 1st if not that is another potential problem


Answered 4th Jul 2011

In my humble opinion,

rapid set is usually good but i prefer to use standard time adhesive on porcelain tiles.i once had this problem with rapid set over heated floor, also dot/dab is fine in itself but you need to make sure adhesive has got a good bite to tile so spreader would have made sure its well wiped into tile and floor. wetting the back with a wet rag also helps adhesion as even a small layer of dust can hinder the adhesive working properly, and mainly it is an absolute must that fexable tile adhesive is used on wooden floors, a sub floor of ply wood is best used then tile over it. never tile over floorboards! Hope this was of some help to you(probably not much? lol) but i hope you find a solution to your problems.

all the best

Evans & Son Tile Solutions


Answered 4th Jul 2011

Procedure for laying underfloor heating and tiling on wooden floor

we always lay a subfloor of marine ply to a depth no less than 18mm

This should be screwed every 6"

Floor should then be primed with the priming agent supplied with all good underfloor heating

Once primer is dry underfloor heating matrix can be laid out

We would then lay a highly flexible latex levelling compound over the heating matrix and allow to dry for at least 24 hours

When laying over timber there should be no cutting corners with cheap materials we only use Bal rapid set Porcelain adhesive and flexible grout

NEVER EVER USE DOT AND DAB ON FLOOR TILES.......... if you miss a corner foot traffic will eventually crack the tile. 10mm notched trowel with a full bed of adhesive!!

In 11 years of business we have never had 1 call back


Answered 13th Jul 2011

Tiling relies on the notches for grip dot and dab is not a suitable, also depends on the wooden floor and the movement in it


Answered 4th Jul 2011

was the floor prpared properly, also was the correct tile adesive used for porcelain tiles. dot and dab will usualy cause problems with the tile sounding hollow and would normaly lift/fail within a short period of time.


Answered 4th Jul 2011

All above are correct but also has he definatlety used a flexible adhesive?If not will have major problems


Answered 5th Jul 2011

First off the dot & dab method over under floor heating is why your tiles have failed as the warm air in the voids where tile adhesive should be expands and makes the tiles pop off the adhesive. The heating element should be encased in a solid bed of adhesive or a flexible floor screed.if the heating is covered the dot & dab method is fine as long as 50% of the tile is covered in none wet areas. For areas of wetness 100% of tile needs to be covered.fitted loads of under floor heating kits most say between 2-4 weeks before switching on.
Hope this helps


Answered 6th Jul 2011

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