Damp quarry tiles - Farmhouse 1799

[Janet BG]

When we moved into our farmhouse (which is three cottages joined together to form a large farmhouse), we discovered old quarry tiles under the carpet in the lounge, the carpet had been in place for many many years! Unfortunately, the underlay had been glued firmly across the entire floor. After spending days trying to remove the glue, we realised it was a losing battle and decided to install a wooden floor instead. That floor has been in place for around three years.

Now that we're renovating the room, we’ve removed the wooden floor and noticed a strong smell of damp, The house has previously been treated for raising damp in the room.
Interestingly, the areas where we previously removed the glue from the quarry tiles were wet, whereas the tiles still covered in glue seemed fine. However, the skirting boards around the entire room showed signs of dampness. It seems the glue might have been acting as a barrier, preventing the damp from escaping.

I knew little about quarry tiles before today (Google has been my best friend!), but I now have a few questions I’d love some advice on:

1. Now that we’ve managed to remove a large amount of the glue (around 50% of the room), we’re seeing significant efflorescence—so much so that sweeping leaves a noticeable pile of salts. Will this slow down over time? The tiles are in great condition once the glue is removed, so we’ve decided to keep them. Removing the tiles and replacing the floor with a concrete base feels like the only alternative, but we’d prefer to avoid that if possible.
   
   
2. What's your thoughts on sealing them, is there such a thing as a breathable sealer?
   
   
3. Could the rising damp in this room have been caused by the long-term presence of carpet, which may have trapped moisture with no way to escape?

 

[jamest]

I had a similar situation in my front room, except that a previous owner had tried to remove quarry tiles, but with limited success and then filled in the bits where the tiles had been removed with a cement screed or leveling compound. I ended up removing the lot, only to discover the reason the PO had given up removing the tiles half way through the job.

Anyway, the answers to your questions would be yes, no and yes.

In my case, there was a cement floor under the quarry tiles, which I think dated from the 50s or early 60s, but without any damp proof membrane underneath. Sounds as if yours could be similar, at least no dpm. If so, then the moisture that is present under the carpet/wood floor would be from the ground beneath the subfloor. In the absence of the carpet/wood floor, this moisture will just evaporate away into the room. If you keep the tiles, you need to facilitate this rather than suppress it, so don't seal the tiles (which don't need it anyway - hard English quarry tiles were never 'sealed' traditionally, maybe waxed) and if you grout the joints use a vapour permeable material.

With the salts, this will probably get better, but may never go away completely. You just have to live with it, though there may be salt 'neutralizing' treatments available. Someone else may know.

Anyway, that's my view . . . others may differ

 

[Cubist]

The damp and damage to the perimeter walls is the direct result of water trapped under the 'glue' which was used to both seal the tiles and fix the carpet/underlay being forced to the sides of the room as its only avenue of escape. The salts you are seeing appear on the surface of the now 'glue' free tiles indicates that the floor is now beginning to breathe properly as it was originally intended. Yes, you could remove the old quarry tiles, dig out the ground below and install a new concrete slab BUT that would merely repeat the mistake that is currently causing damp to appear in the perimeter walls.

Using any kind of technically effective sealant over the tiles would produce exactly the same result - so just don't bother.

Continue removing the old 'glue'. Let the floor breathe and while it dries continue to remove the salts - the walls will begin to dry out while you are doing this. Repair/replace any damaged tiles and use suitable rugs to cover the tiles after they have stopped efflorescencing.

Your other viable option is to dig out the floor and to install a limecrete solution.

 

[Janet BG]

Thank you so much for your reply, all makes perfect sense.. the salts are really prevalent in one half of the floor and seems to be completely white when left for a few hours, we sweep it and vacuum it a few times a day.. Do you know how long it will take to see the salt removal slow down?

 

[Cubist]

You'll need to give it a couple of weeks at least, and perhaps until the weather outdoors begins to improve, after removing the glue from the surface and during that time you should resist cleaning the floor with water other than on a damp cloth - too much water would risk diluting and washing the salts into the grout lines and back into the surface microscopic pores of the tiles only for it to surface later. Stiff brush and vac for now would be best if you can. There are salt neutralisers available from the likes of Screwfix and ToolStation that some have reportedly used to good effect but I have no direct experience of these.

 

[mardinor]

Had a similar situation 20 years ago. Strategic neglect works wonders. Just keep walking over the floor while leaving it to breathe supplies sufficient friction and buffing to remove all salts over time. Builders dust accelerates the process. Just lower your standards of 'prettiness' for a while and/or don't allow house guests.

Lovely floor that is bombproof, resilient and (ultimately) attractive

 

[Janet BG]

You'll need to give it a couple of weeks at least, and perhaps until the weather outdoors begins to improve, after removing the glue from the surface and during that time you should resist cleaning the floor with water other than on a damp cloth - too much water would risk diluting and washing the salts into the grout lines and back into the surface microscopic pores of the tiles only for it to surface later. Stiff brush and vac for now would be best if you can. There are salt neutralisers available from the likes of Screwfix and ToolStation that some have reportedly used to good effect but I have no direct experience of these.

Amazing, thank you