Hi There - help needed

[Dave Regal]

Hello all, I am a DIY enthusiast living in France. I recently started up a general handyman business to help people in my village.

Recently, a friend of a friend asked me to help him to find a solution to a problem he has with a tiled external terrace. The terrace is tiled with good quality external ceramic tiles. Apparently, the tiler (who is now retired) put a plasic membrane between the flat roof to an outside building followed by a concrete screed (5cm thick) then tiled on top. The plastic membrane was put in place to prevent leaks from the tiled terrace seeping through the ceilings of the rooms below the terrace. The fix has worked for some time but, now, there is evidence of water starting to leak through the ceiling again.

The owner (who is a pretty strong minded South African retiree) has suggested making a jig to control the depth and width of cut made by a diamond bladed cutter to remove the old grout then to refill the joints with a COLD WELDING product that he has obtained in SA. The product is very hard, very expensive and rapid setting. According to the product web site, it is really for use in repairing things like exhaust pipes, broken fixings and tiles, not for grouting.

I would like to suggest a better solution using flexible tile grout. The use of a jig to make the cuts to remove the old grout seems viable, it's just the material to use for regrouting that will give good adhesion, waterproofing and flexibility so that it doesn't crack again (the existing grout has come away from the tiles leaving minute cracks that all ow water to get in and, in winter, lift the tiles. Some of the tiles give a hollow sound when tapped so the bond between the bottom of the tile and the cement screed is clearly not good.

ANY suggestions for a suitable product would be most welcome. ALSO, if the idea of removing the old grout completely is unnecessary, what degree of cleaning would be acceptable.

thanks in advance

 

[Gazzer]

Hi Dave Regal and welcome to tilersforums.com

 

[peteablard]

If some of the tiles are starting to lift then you need to address that problem first IMO

 

[White Room]

Hi and welcome.....

 

[DHTiling]

I think you might need to start from scratch here.... no point in trying to fix what sounds like it has failed..

 

[AliGage]

Hi and welcome.

Agree with Dave here, no ammount of grouting will rebond the tiles. Sounds like a start from scratch job.

 

[Dave Regal]

I think you might need to start from scratch here.... no point in trying to fix what sounds like it has failed..

Thanks to you and all the others for sound advice. I suspected that the case was lost before I asked but your professional advice has enabled me to go back to the person with the problem and clearly explain, with backup, the situation.

As an idea, if we left the tiles as they are and tackle the problem from below, make the ceiling water tight, would that be a feasible approach? The tiles that are hollow are few and far between and are certainly not loose. I guess they will last a few years although the winters here are pretty harsh. Any thoughts?

 

[AliGage]

Making the ceiling water tight won't stop penertration through the loose/failled tiles on the top.

 

[Dave Regal]

Making the ceiling water tight won't stop penertration through the loose/failled tiles on the top.

Agree 100% but the quantity of water that penetrates is at nuisance level rather than significant. If the water is retained in the 300mm thick concrete floor of the terrace rather than being allowed to escape through the ceilings, do you think the situation would be acceptable or would it open up a whole new can of worms?

Clearly, ripping up the old tiles, establishing a truly waterproof barrier below them and then relaying properly is the bast solution BUT, is it the ONLY solution that is viable.

Thanks for your help.