Help!: Refit cut porcelain tiles; add bevel ?

[Adrian2009]

We had a conservatory floor tiled by our builders about 3 years ago.
I noticed some tiles sounded hollow within a year but these were at the edges, so left. Not sure how the problem progressed but ended up checking thorougly and now have about 20% of floor tiles lifted with about 3/4 of these fully recovered. When working on this I soon realised that although the tiles are very strong in some respects they are also very easily chipped on the top surface with one careless chisel.

The problem is that tiles are now obsolete (Magica swain beige). I have plenty of spare tiles but not all the right sizes ( we have a pattern with 4 sizes), so need to cut down some of the largest to make up for broken ones. As these are not at the edges should I attempt to put a bevel back on or just live with the edge that is cut ?

Not sure what caused the problem, the rest of the floor is very good. When taking up the tiles nearest the edges they were very easy to get up and left no cement on the concrete floor, which feels chalky. (The concrete floor was spec'd over the top bieng over 6" thick with reinforcement as we didnt want any cracking in floor due to movement - and I shold add we thought builders did a very good job).

Should I use PVA before getting tiles reset ?

Thanks for any advice.

[Diamond Pool Finishers]

you dont mention wether glazed or not!, if you have plenty, you could try to bevel if ,not youll have to live with cut edge i would use SBR but PVA is ok m8

[diamondtiling]

If they are porcelain tiles with a rectified edge than you will never get that edge onto another tile yourself, they were done by a machine and then polished in the factory. You say that the tiles sound hollow at the edges? thats sounds like dot and dab fixing, if it is not then the fixer may not have been checking for 100% coverage as he/she laid them, it sounds even more likely that it was not a competent fixer when you say the edge tiles were easier to get up, classic case of two dabs of adhesive to stick them down. PVA is a no no in this situation, you will get many people on here saying the same, use an acrylic bond instead which is available from all tile suppliers, The adhesive should have been a flexible one as should the grout so make sure you use one for fixing the new tiles, where are you as someone may be able to call and give you some advice.

[diamondtiling]

you dont mention wether glazed or not!, if you have plenty, you could try to bevel if ,not youll have to live with cut edge i would use SBR but PVA is ok m8

why do you say that PVA is ok? It is not ok and all adhesive manufacturers warranties will be null and void if any future problems arise with tiles lifting due to adhesive breakdown.

[Adrian2009]

I dont think they are glazed, they are described as porcelain stoneware, and they dont have a gloss finish.

Also, I need grout: It was Howtex Grey , they have been taken over by Weber who have replaced it with a Silver Grey. I guess this is nearest match and should blend in ?

[Diamond Pool Finishers]

how is pva going to break down tile addy if he paints it on to seal dusting sreed and leves it to dry before setting tile m8

[Adrian2009]

The adhesive was Howtex Porcelain Rapid Set. It was appled with a comb , not dot & dab; the problem seems to be that the cement did not bound to the concrete properly.The last few tiles I lifted, which were partly secured ok, were quite difficult to remove, the problem area is continous in one corner following the dwarf wall and being a few tiles wide.

The builder has offered to come back and refit the tiles if I did the lifting & cleaning.

[diamondtiling]

Gooner, have you been hiding in a cave mate for the past few years? next time you are going to buy mapei, ardex, granfix, bal, in fact any adhesive tell the supplier you will be using PVA to seal prior to fixing.

[diamondtiling]

You may have a suspect area of screed Adrian, is it crumbling or dusty? can you easily take the surface off, cement not bonding is usually caused by damp screeds, wrong adhesive, in-correct bonding ie PVA.

The builder should really be lifting the tiles and re-laying them, his job so he should fix it.

[Diamond Pool Finishers]

i was trying to save ady money he is just patching up , you want to lay off the coffee a bit dimond i never use pva you muppet read my post

[Diamond Pool Finishers]

you are jumping to to many conclutions dim , dot and dab, screed breaking up, wot next!!!!

[murf]

steady on gooner. Are you sure you'r not a millwall fan?

[diamondtiling]

Gooner, sit down, have a rest and chill out. Firstly no one is jumping to any conclusions, that would be the case if I had simply stated one problem and one method to resolve it, however as I asked Adrian to check out the theories I was offering I believe that would come under narrowing the problem down. Hollow tiles are usually the result of dot and dab fixing, no enough coverage with a trowel or a suspect screed. I have as you have asked me to do re-read your reply and Yes you do actually say the words "but PVA is ok m8".
In regard to your point about coffee, I dont drink the stuff and fail to see its relevance, I have never starred in any programmes with Kermit or Miss piggy so how coulod I be a muppet? I have never met Jim henson and I believe he is actually dead.
I do hope this clears things up for you and allows you to calm down.

[Diamond Pool Finishers]

ask any plasterer many a good screed layd using pva allthough i now use sbr myself,anyway we know wots got to him there next man u

[jay]

hi adrian 2009 couple of questions how long did the builder leave (render)cement to dry befor tiling . is there a perimater expansion joint and just how soft is the render (can you dig a hole using keys

[Adrian2009]

I dont remember how long was left for concrete to dry out, but am guessing around 2 weeks with conservatory roof on for at least a week.

Also, not sure but dont think screed was added, concrete was left with even enough surface.

Concrete is very hard and even with small 1/2" chisel it takes a heavy blow to break surface.

[jay]

hi tiles may have been put down to early on concrete needs time to cure (dry out) has a expansion joint been left between tiles and exterior walls

[Adrian2009]

yes there is a joint between tiles and wall, filled with grout

[diamondtiling]

thats not an expansion joint mate, it should be a manufactured expansion joint, it allows for movement and helps to eliminate cracks etc

[jay]

hi that joint should be filled with silicone that why your edge tiles are lifting off .the floor tiles need to move (expand) if they cant move sideways they move up or lift could also be not letting slab cure lack of primer but sounds like lack of expansion hope that helps

[Colour Republic]

You say that it seems to be the cut tiles at the edge that are lifting. It is very probable that the tiler laid the main floor and left the cuts until last - if he or she did then there is a possibility that the adhesive used for the cuts was mixed up differently and mixed too dry so they did not get a good bond before the adhesive went off

So it may have nothing to do with the screed - Just a thought

[Dave]

A 6 inch screed/concrete floor....2 weeks is no where near enough drying time...i think this is why they de-bonded....

Bu that is hear say now after the amount of time it has been down....

Personally i would lift the old tile and re-tile with correct prep work and NOT use pva as a primer/dust proofer..

[Dave]

i was trying to save ady money he is just patching up , you want to lay off the coffee a bit dimond i never use pva you muppet read my post

Please do not post offensive remarks towards another member.....thank you.!

[whitebeam]

quote (I shold add we thought builders did a very good job).
Sadly if they had you would'nt be lifting tiles already

[doug boardley]

personally Adrian, I'd bite the bullet and lift all the existing tiles, what are you gonna do if all the others start debonding and your tiles are obsolete?

[Adrian2009]

Thanks to all who replied.
I think the drying the time looks like it was the main problem.
Anyway, I now have a clean concrete floor in good condition, if still a bit dusty.

I have already bought the recommended adhesive: Palace Porcel Fix Fast.
And having reread the instructions on this bag it looks like i dont need to add any pva or other substance to the concrete prior to tiling, just a vacuum clean perhaps (if the floor wasnt dried out in the beginning it certainly is now.

[Adrian2009]

Hmmm, just seen Doug's post re lifting all the tiles. Had considered this, but decided that the main cost of work to date is in my time (which I have enjoyed to a point - new skill !) and the cost of refitting is about £160; Worst case scenario, in another 3 years have to start again, cost estimate around £750 + labour = £1,000 plus, so I think it's worth the risk. Also, must say the other tiles are really sound, so unless some sort of ever increasing de-bonding is happening I should be ok.

[jay]

good luck hope you learned something