Tiling over cracked concrete

[Mike S]

I'm planning to tile an old concrete floor in a downstairs bathroom. It's cracked in places and even makes a slight creaking noise in places when you walk on it although there isn't any noticable movement. I was planning to cover it in self-levelling compound before tiling. Would that be enough or should I consider something more substantial in the way of repairs?

I also read that one should not tile onto concrete that doesn't have some sort of DPC treatment. I doubt it has any, although can't be sure without digging up the floor. The concrete has been exposed for a couple of years now (project delays!!) and there is no visible sign of damp. However, should I also consider some sort of damp treatement before tiling?

I'd be grateful for any suggestions. Thanks!

Mike

 

[tictic]

if there is no DPM then imo dont tile it.

as for the crack how deep/long is it,for a repair you could use an expoxy resin...cut out the section(crack) and infill with a siutable epoxy..

google mapei and they have the stuff for this.

 

[Mike S]

if there is no DPM then imo dont tile it.

as for the crack how deep/long is it,for a repair you could use an expoxy resin...cut out the section(crack) and infill with a siutable epoxy..

google mapei and they have the stuff for this.

Thanks for this. Actually, following further inpsection I don't think it's a crack in the main concrete slab, but a red coloured screed that was laid on top of this. I chiselled a 5cm diameter loose piece out of it that was about 1cm thick and found that is was lying on top of a smooth solid surface below that. So in terms of depth, I guess the cracks may be up to about 1 cm deep, although none of the cracks are wide enough stick a pin or fingernail into except at the very top of the opening.

The creaking sound is I think at the interface between the screed and the concrete below on either side of the cracks. Apart from that the floor feels pretty solid.

After repairing the cracks with resin, should I lay some sort of DPM below the floor leveling compount (Mapei Latexplan) or perhaps use one of those decoupling mats?

Thanks again,

Mike

 

[joe-90]

Ditra matting is very effective.

 

[Mike S]

Ditra matting is very effective.

Thanks Joe. How does that work exactly? Could I lay this onto self-levelling compound? How do I stick it down? Do I then tile onto this using ordinary flexible tile adhesive? I bought some for tiling on concrete, but maybe I will have to take it back and get something else instead?

 

[joe-90]

Have a look at this site.

http://www.schluter.co.uk/produkt.aspx?doc=6-1-ditra.xml&pg=funktion

 

[Mike S]

Have a look at this site.

http://www.schluter.co.uk/produkt.aspx?doc=6-1-ditra.xml&pg=funktion[/QUOTE]

Thanks, looks like that might be the way to go!?

 

[Richard C]

Ditra matting is very effective.

In this case, very good advice

 

[roughcaster]

Joe-90 is the Daddy!!!

 

[Richard C]

Joe-90 is the Daddy!!!

Now your just teasing me

 

[roughcaster]

Joe-90 is the Daddy!!!

Now your just teasing me

Your turn again next week Rich'.

 

[tictic]

Ditra matting is very effective.

cracked and creaking substrate.....dont think ditra is going to help ere...!!