cracking and uneaven slc over concrete floor

[Sean Kelly]

I looked at a job yesterday where a plasterer levelled a concrete floor for the customer. The customer was out for the day so did not know what the plasterer used. The 'latex' (this is what the plasterer said he used) is cracking all over the surface. It is hollow in places when I tap it. The manhole cover has just had a blob of 'latex' poured on top of it. There are 'wave' marks everywhere. My personal feeling is that either the liquid/powder mix is not correct &/or the concrete floor below has not been cleaned or primed. I have advised the customer to speak to the man that completed the work. Can I have your views on what the cause of the cracking to be. I have advised the customer that I would not tile onto this surface as I feel that in a very sort space of time the tiles/grout will start to crack too. Also, any advise on how to tile over a manhole cover so that in case of emergency it can be lifted without too much damage to the tiles. The customer wants a modular 3 tile design on the floor. Cheers Sean

 

[kilty55]

deary me doesnt look too good does it. im with you sean re level it yourself,never tiled a manhole cover im sure dom done one on a sandstone job a while ago

 

[diamondtiling]

He has mixed that too wet and its not a latex version, that has been mixed with water.

http://www.tilersforums.com/members...tone-floor-picture15203-inspection-cover.html

Manholes are pretty straight forward Sean, you will need to raise it level with your tiles. If its just a lid then it needs changing so that it can be tiled into, again thats pretty straight forward to do.

 

[faithhealer]

just one big mess, very iffy

 

[Andy Allen]

omg what a mess..............its got more waves than the north sea

 

[simon1]

Would scrape up as much as you can and re-level yourself

 

[Sean Kelly]

He has mixed that too wet and its not a latex version, that has been mixed with water.

Picture 2 of 15 from Sandstone floor.

Manholes are pretty straight forward Sean, you will need to raise it level with your tiles. If its just a lid then it needs changing so that it can be tiled into, again thats pretty straight forward to do.

Cheers Diamondtiling. Nice manhole cover in the pic. If the customer gets her money back from the other guy and I get the job of redoing it i guess it's just a case of hammering the slc and sweeping up the pieces. Been looking around for manhole covers online but not had much luck in finding one that I can tile into. I also found out yesterday that this poor customer let the plumber tile her downstairs WC. Needless to say, the customer is not happy with the end result. I've seen the workmanship and I would not be happy either. This customer is not having a very good weekend! Cheers Sean

 

[DHTiling]

Could have been poured to thick for the SLC to cope with.. primer is an option , suction usually causes air bubbles but dust will cause de-lamination.. either way it is a rip up and re-do..

 

[doug boardley]

looks like he's trowelled it with a live snake!! was there any under screed ufh turned on there Sean?

 

[Sean Kelly]

looks like he's trowelled it with a live snake!! was there any under screed ufh turned on there Sean?

No UFH Doug. Just an old concrete floor. The customer does not know what condition it was in because there had always been carpet over it.

 

[White Room]

Looks like it has dried far to quick, dos'nt look as if there been any primer used either.

 

[Ajax123]

That type of crazing is generally associated with over rapid drying of the screed. I agree with Whitebeam. I would guess no primer onto old dry concrete and the concrete has simply sucked all the moisture out of the levelling compound. This would also account for it delaminating as it dessicates before having time to "grab" on to the subfloor. Take it up and start again is my advice

 

[Sean Kelly]

That type of crazing is generally associated with over rapid drying of the screed. I agree with Whitebeam. I would guess no primer onto old dry concrete and the concrete has simply sucked all the moisture out of the levelling compound. This would also account for it delaminating as it dessicates before having time to "grab" on to the subfloor. Take it up and start again is my advice

Excellent point there Ajax123. I thought it looked like it dried too fast, but then I dismissed that because it would have been laid down in coldish weather conditions. It had not crossed my mind that it was being sucked up by the concrete. I will remember that one for the future. Cheers Sean

 

[Sean Kelly]

Customer mailed me to say that the plasterer says he can't scrape up what he has already poured. He will come over on Saturday to pour more 'latex' over the cracked 'latex'! I have advised her not to let him do that! One point about the manhole cover.....I was in Selco today looking at manhole covers suitable for tiling. I could not find anything that looked like the one that Diamondtiling posted. Am I right in thinking that if I did find one like Diamontiling's pic would I have to dig out the old one and replace with new? I was thinking of tiling around the existing cover and siliconing around the edge (so that it can be lifted at a later date). I would also have to drill holes in the tiles to gain access to the screws. Has anyone else done this? Cheers Sean

 

[White Room]

Your talking an inset manhole I believe, Yes looks like it would need changing so the tile could be laid within the manhole........

Slc over whats already there, thats a waste of time.