Best fixant for terracotta floor tiles?

[Cadeby]

Hi, can anyone suggest the best "mix" for fixing terracotta tiles to a concrete interior floor? I have been given loads of conflicting suggestions, eg. sand and cement, with or without PVA added, OR sand and lime in all manner of different ratios!

Suggestions from people who have successfully laid their tiles would be appreciated. Thanks!

[M]

The same as for any ceramic floor tiles - a cement-based ready-mixed floor tile adhesive and a notched spreader.

Malcolm

[Bobc]

"Hi, can anyone suggest the best "mix" for fixing terracotta tiles to a concrete interior floor?"

If these are actually old terracotta tiles rather than modern 'look-alikes', then use a high quality adhesive such as Lanko 524. Generally in France, ready mixed tile adhesive such as Fermafix Pro is intended for wall tiling. Floor tile adhesive is always mixed from dry.

This should be trowelled out to a bed of around 5mm and not combed. Bed the tiles in this, carefully by hand. Genuine, old terracotta tiles are very fragile until they are laid and jointed and are very different from factory made ceramic tiles.

They should also not be bedded-in with a rubber mallet as with ceramic tiles.

The same rules apply to tiles made from reconstituted stone such as Pierra. www.pierra.com

Ideally joint with a sand and lime mix, or for more durability Weber et Broutin Fermajoint DL.

Regards,

Bob Clarke
http://perso.wanadoo.fr/grindoux

[zeb]

Also, I think you have to joint terracotta (and pierre) carefully using what looks like an icing bag as the tiles stain easily, rather than slosh the jointing compound over the floor and then wipe it off as you can with glazed floor tiles.

regards.......helen (but perhaps I have been looking at too many DIY books - I should get out more!)

[Peter72]

We have bedded our old reclaimed tiles in a thick bed of lime/sand at 1:5 laid onto wet PVA over concrete, our tiles are all sorts of thickness and need a thick bed. Grouted with a sloppy lime mix from a jug and the excess scraped off before acid washing and sealing with linseed oil/white spirit.

The local advice is that too strong a fix will make the old fragile tiles crack. They look lovely.

Regards

Peter

[Bobc]

 "We have bedded our old reclaimed tiles in a thick bed of lime/sand at 1:5 laid onto wet PVA over concrete, our tiles are all sorts of thickness and need a thick bed. Grouted with a sloppy lime mix from a jug and the excess scraped off before acid washing and sealing with linseed oil/white spirit.

The local advice is that too strong a fix will make the old fragile tiles crack. They look lovely"

You have obviously has good results with your own installation. The old terracotta tiles that I have removed from old properties have usually been laid on a lime/sand mixture which has not stood the test of time - but these were simply laid on earth below. Over any given area, only 25% of the tiles have been salvageable. If you have a concrete subfloor there is no reason not to use a high quality modern adhesive. If you have tiles of varying thickness, then simply increase the depth of the adhesive bed. There is no possible way that this method will cause tiles to crack.

Before jointing use a product such as Pierra Protection Avant Joint and then joint in the normal way with a trowel. Clean up with a sponge and plenty of clean water. Finish with a product such as Pierra Patine de Protection. Certainly no need for acid washing which can damage the surface of very old tiles.

Regards,

Bob Clarke
http://perso.wanadoo.fr/grindoux

[Lespearsons]

We laid old terracotta tiles on aa inchish thick dry 4 sand to 1 cement mix. IGrouting (very small gaps) with cement. Any spills wiped off using sawdust.

That was 10 years ago and it worked fine.

[Cadeby]

Thanks for all the advice. We have decided to opt for the modern adhesive method in the room with the smoothest floor, and see how we get on. We may resort back to the lime and sand "traditional" method in the room with rougher concrete, especially if we mess up!!!

[Peter72]

Bob,

We used the adhesive method for the new terracotta tiles but the maximum thickness recomended is only 6mm and is a swine to level even at that thickness, it also costs an arm and a leg. The lime/sand mix is cheap and has been in use for well over a hundred years on earth floors. I see no gain in using modern alternatives that are so expensive when the traditional mix works.

A point I would like to throw in for discussion is :

Why do many French professionals insist in doing things the hard and expensive way.

Some of the things that come to mind are: Plumbing - why so many pipe sizes and different types of fitting? Why do plumbers insist on braising tees into large diamiter pipes, a job which takes much longer than a ready made joint? Why do they still use screwed iron pipe for central heating and over size boilers? which I feel quite at home with since working in power stations for many years. Cynical old ******s might think it is something to do with the time taken to do a job and the amount charged.

Regards

Peter

[Bobc]

Peter,

As I said in an earlier posting, your method has obviously worked for your own tile installation and for others in the short term.

I would not agree that it has worked well for over a hundred years. My sources of old orginal terracotta tiles come from properties where they were laid on earth using a mixture of sand and lime. The tiles are fragile and the mixture moves with result that tiles move and crack. From these old properties the majority of the tiles are cracked.

You have not mentioned the brand of adhesive you have been using but most professional ranges can be used well over 6mm.

Within my work I try to use traditional methods, but only when they are better than modern methods.

Re your other points - I do not understand your comment re French professionals 'doing things the hard and expensive way'.

For my plumbing work I use the flexible plastic PER system as do many other French professionals.

Others use older, more traditional methods which suit them.

I have not worked with any French artisans who prolong the job in order to increase the cost - I thought that was exclusive to the UK - AAA Plumbers, etc!

Good luck with your project.

Kind regards

Bob Clarke
http://perso.wanadoo.fr/grindoux