Tiling over Quarry tile

[DUV12]

Hey All,
First time post!

I have a 1850 house - long story short, i have Quarry tile on the entire downstairs floor which is not in good condition, non-loose etc but lots of tiles patches with compo to make flat for the carpets that were here when we moved in (May-23).
Question- Can I tile over them in a special way?
The Red needs to go. But i understand that DPC-ing and wooden flooring isn't an option as its Ash underneath.

My thinking is that if the tiles on top are not so large ( maybe 200 x 200) I'll still have enough breathing space around the tiles.

The walls were already Dryroded 30yrs ago and has failed - I have chipped up 1m and renewed this with Dryrod sticks.

Any advise is appreciated.

David

 

[jamest]

I haven't ever tried what you're proposing, but I have put new flooring (both tiles and wood) over (thin) concrete slab that has no damp-proof membrane underneath. I can't be sure that my solutions are effective, but I haven't had any problems and the floors have been down for some time. With tiles, I've used Adhere Cal - a hydraulic lime-based tile adhesive made by Secil - it seems to work fine on old concrete (I asked someone at Mike Wye about using it on concrete and they said they'd used it effectively on concrete themselves) and pointed the tiles (terracotta and limestone) with lime putty mortar (a tedious job, but gives a very breathable joint if you don't run sealant over it, it looks good too, once done, but you do need to ensure that the mortar cures properly else it will shed grains of sand all over your nice new tiles - alternatively you can use Adhere Cal as a grout). With wood, I've floated engineered oak flooring over an underlay with an impermeable plastic membrane underneath that has grooves in it to allow moisture to get out from under the floor. It's about 2 or 3 mm thick and made by Newton Membranes (there are other manufacturers that make something similar) and was designed to be used over slabs or screeds that haven't completely dried out - you need to ensure that moisture can get out around the edges of the flooring with this method.

I'm sure others have tried different things and what works for one floor, mightn't be appropriate in other circumstances, but I offer the above as two options to consider.

 

[DUV12]

Hi Jamest,
Thanks for the quick response and advice. I'll take on board your product suggestions too.

 

[a twig]

I suspect you’ll find a fair amount of cynicism here about supposed effectiveness of Dryrods and the like - assuming there is damp what other steps have you taken?

 

[DUV12]

Hi a Twig.
There is no damp on the tiles and the readings are normal for the material. Damp is, however on the outer walls, high readings and literally paper falling off. Spanning 4m in both rooms. Outside is fine, no damp readings. Dryrod is the only provision at present, it's been 4 weeks and I'll eventually use dryrod morter sealant to re coat the walls as the manufacturer recommends.

I've done nothing to the floor yet as we are half way through knocking walls down.

 

[malcolm]

I suspect the Dryrod and the Dryrod sealant will be a mistake. Looked them up and water repellent rods sound silly. Sealant is always silly. You don't stop damp by preventing the water from getting out.

My rules for damp that work for me (no damp course) are exterior walls need to be breathable to the outside so no waterproof paints or renders. Additionally the ground level outside should be maybe 6 inches lower than the floor level inside. Gutters not overflowing and drains not blocked are a bonus.

Damp meters are not designed for walls (unless the walls are made of wood). The damp industry uses them to show that dry walls are damp.

 

[DUV12]

Thanks for the information, I'll assume you are correct on the dryrod and await the law suits then. This was recommended for my situation.

Also it didn't answer my question about tiling over the quarry tiles. The dryrod maybe I should have left out as it seems to have mislead my question.

Thank you anyway.

 

[a twig]

The dryrod was definitely pertinent, the reason for the interest in the walls is if you already have damp in the walls, then a less breathable solution on the floor will only make matters worse.

There aren't lawsuits against these companies because there are several potential causes for damp, and it's almost impossible in a legal scenario to prove that the cause of failure was definitely the one that the product purports to solve. Added to that, the mortar sealant which is applied (as the name suggests) seals the walls and traps the moisture inside. Thus a few months after application, sticking a moisture meter in (which as Malcolm correctly states are not effective at measuring anything other that the moisture content of timber) will show the surface to be dry, but the structure of the wall will remain wet behind it and continue to deteriorate.

At some point the sealing will fail (usually just far enough past the guarantee period), the plaster etc will drop off to reveal a wet wall, at which point the rods will be declared to be in need of renewal, and the whole cycle starts again.

Invariably such solutions are only recommended by their purveyors, and in reality the usual period property renovation tasks of addressing rainwater goods and ground levels, and remove non-breathable finishes and apply appropriate ones are really the only solution.

Specifically onto the quarries question, generally tiling over existing tiling is always a shortcut whatever the age of property, and really should be avoided. Assuming you are intending to use ceramic tiles with a modern adhesive / grout, then no, there a way to do so to maintain breathability. And thus we are back to the point about the walls, if the walls are dry and breathing effectively then you can often get away with a non-breathable or not very breathable floor, but from what you have described in your situation, that doesn't appear to be the case.

 

[mardinor]

It sounds like you're adamant the tiles need to go, but let me plead for clemency. We also have quarry tiles covering the entire ground floor, when we moved in uncovered from under lino and in a terrible state. They really are robust, and easy enough to clean off. The results are better than anything you can cover them with, and the patina of wear is a treat every day. Wonderfully cool underfoot on a hot day. And any that are beyond saving are relatively easy to replace with reclaimed ones.

If all else fails, at least just cover them over again with carpet (felt underlay) or rugs. Future owners will thank you.

 

[DUV12]

The issue with repairing them is that there are far too many filled in from the last carpets. But also as this room was the original space and we've knocked through to the kitchen (1980's) and passage way from room 1 to 2 (kitchen being 3) there is a difference In floor materials. Room 3 and the passage are concrete. Room 3 has a 50mm height difference so I'll need to fill that anyway.

TBH, if the room was a full original room then I would keep them.
Hopefully some images are seen with this post.

then the reason will be full circle to what i see.

 

[LadyArowana]

Those look like they would clean up ok, seems a shame to completely trash them by sticking something boring and modern over the top.

 

[jamest]

Yeah, a lot of those look OK. I would be inclined to clean up the good ones, source some similar tiles - terracotta perhaps - mix them up randomly with your old ones and then retile the whole area.

 

[DUV12]

I think I'll pull them up and flagstone the whole room. After seeking advise from a porous stone fitter.

One man's piss is another man's porridge and all that.

 

[ElectronicFur]

My experience echoes what Twig said. I found that with a floor on top of soil or ash, if the flooring materials are not breathable then the moisture will go into the walls. As yours was carpeted, this may well explain your damp walls. My walls were very damp and the wallpaper just peeled off, due to non-breathable flooring. It took about 6 months to fully dry out after removing the non-breathable materials, but the walls were already noticeably drier after a month. Flagstones will provide a breathable solution, just make sure they don't seal them, and that a breathable grout is used.

 

[DUV12]

Thanks ElectronicFur.
I think the flags will be the best compromise, Quorn stone gave me their specialist tiler to advise and fit. If it was more straightforward I'd do it myself but I have more than enough on my plate, knowing when to pay out for good experience is the key..

The carpets could well be the original wall culprit. It didn't help they Installed rads under the effected windows which counter to beliefs draws moisture, again compounding the situation. Amongst sealing the front door we're slowly plugging the gaps...

 

[Stonehouse]

I suspect the Dryrod and the Dryrod sealant will be a mistake. Looked them up and water repellent rods sound silly. Sealant is always silly. You don't stop damp by preventing the water from getting out.

My rules for damp that work for me (no damp course) are exterior walls need to be breathable to the outside so no waterproof paints or renders. Additionally the ground level outside should be maybe 6 inches lower than the floor level inside. Gutters not overflowing and drains not blocked are a bonus.

Damp meters are not designed for walls (unless the walls are made of wood). The damp industry uses them to show that dry walls are damp.

Hi Malcolm we have some cement from the ground that comes up to make the hearth of our fireplace. It is all lime around. Not ideal and has a dpm under concrete and black paint over the concrete.

As it’s all lime around will the water be able to escape?

I assume we can use any tile adhesive on the concrete?

Thanks so much