Slate Flags Rotten or Not

[jason slater]

Need advice. Just discovered slate flags under an ashfelt floor. I've lifted some and all were sitting on the earth and were soaking wet. I'm sure there is good stone within each flag but the surfaces top and bottom are flaking quite deeply.

Does anyone think they can be saved and re-used if so how do i proceed?

Cheers

Jason

 

[Moo]

Our flags had been covered with cement render, then lino, then underfelt, then carpet, so they were pretty wet and flaky by the time it all came off.

We just left them where they were, with a very occasional sweep or mop. and they are fine. Visitors comment on their mellow charm.

Mind you, when the builder had to life a couple in order to lay a drainage pipe we were amazed at how thick they were - at least three inches!

 

[chuckey]

I guess that there is a possibility of when the stones have dried out they will stop flaking. I say this because the masons that built your place thought that these stone were good enough for flooring. The ashphalt was probabley laid early in the 20th century to combat the rising damp.
Frank

 

[Moo]

I guess that there is a possibility of when the stones have dried out they will stop flaking.

That's exactly what happened to ours.

 

[jason slater]

Thanks for your comments.

Just spoke to a local stonemason he says they will be fine, it is a matter of taste when it comes to finish, but they should wear in.

They appear to be very different thicknesses, any ideas of how to relay them. Dot and dab? Sand? ??

cheers

Jason

 

[chuckey]

You said the earth was soaking wet, normally one would put in a DPC membrane to combat this. I had a similar system as yours but for ashphalt read latex bound concrete screed. I dug out some soil out, put in 6" concrete, DPC membrane, 2 " foam insulation, then 18mm P5 flooring grade T&G chipboard then the flags. The chipboard is overkill but it makes the laying of the flags much easier. the flags were dot and dabbed on 6" blobs of very well plastisticiesd mortar. When you welly the flags down with the biggest rubber mallet(sledge hammer?) you can borrow, you need some space where the excess mortar can flow into. Sand does not flow that easily.
The purists on this site would use limecrete instead of concrete and not have the DPC. I used concrete because my house does not have any foundations and I hoped that sufficient concrete would flow into the joints (gaps) between the stones to tie them together and to act as a surrogate foundation for the walls.
If you lift them all to do a mega job, do string out the room to make sure that the re-layed flags are actually running true to the rooms major axis. Don't ask me about checking this
Frank

 

[MdB]

Putting a DPM down will reduce the evaporation from the floor. This in turn will make the underfloor fill wetter which can then cause damp in the base of the walls.

I have a very dry floor (complete with DPM) and failed plaster 100mm up all the walls due to this as the DPM doesn't go under the walls.

 

[Nemesis]

When we uncovered our flags from the layer of grunge covering them, they were soaking wet,

They are laid directly on earth. Now that they are uncovered (some are mortared with lime, others we have still to do) they have dried out.

No lifting, no messing, simply left them in place. We did have to lift one which was 'dropped' by a door - relaid it on sand to level it.

We used to have wet walls in places - we don't now.

As for foundations - period properties don't have 'foundations' as modern houses do, but they remain standing, some for many centuries.