Breathable floors, limecrete or other optoins?

Breathable floors, limecrete or other optoins?

Author
Discussion

Snow and Rocks

1,901 posts

28 months

Tuesday 15th November 2022
quotequote all
I wouldn't worry overly - by all means dig into the wall somewhere to check but when I turned an existing window into a door everything was bone dry internally even down to near ground level.

If you think about it the path for any water to soak up through internal lime mortar around many layers of almost impermeable rock is pretty tortuous even once it gets up through the typically huge foundation stones. Add in the fact that the cement based mortar is still somewhat permeable (just less so than lime) and any trapped water should still be able to escape.

Magooagain

10,004 posts

171 months

Tuesday 15th November 2022
quotequote all
monkfish1 said:
Magooagain said:
I agree with the cement pointing doing no harm to granite rock etc,but what method was used to build many granite and other hard stone buildings?
They won't have been laid in cement mortar
And there's a high chance the foundation stones are laid on soil and probably the rest of the stones are laid with a soil/chalk/lime mortar mix.

So that allows moisture to be sponged up from below the ground level where there is no cement pointing.
So where does that moisture go if it can't get out through lime pointing?
This is a question troubling me on my latest aquisition. Its been pointed in cement inside and out. The stone is harder than a hard thing. Utterley imperviois to moisture.

Ive primed myself to remove it all and repoint in lime, but there no evidence of damp. Yet. But it is stone with rubble in-fill. As you say, by any measure of logic, the lime mortar that is "in" the wall may well be wet. If it stays that way, it will degrade long term.

What to do????
Is the stone worth exposing on the inside and then lime point it? That would help with a drying out process.

I'm in the middle of renovating a large granite house in France. The exterior has an old lime render but two very large areas have been repaired with sand and cement. The client is telling me just to leave it. But I think that's just a budget issue.

I've removed all the plaster to the two principal rooms on the ground floor. This stone house has been built on soil with huge granite stones as foundations and then granite stones with a mixed infill.

The walls are dry. We've had a very hot summer.
I've dug out the floors down to soil and then another 20cms.
Even when the new floors are installed the floor level will still be below the outside soil level. Not by much,maybe about 20cms.
All ground walls in the two rooms will be left exposed and lime pointed.
I don't I visage any problems.

Floor spec. 100mm type one,20 mm sand blinding,dpm,100mm rigid insulation,20mm perimeter insulation,vapeur barrier,120mm Concrete.

C Lee Farquar

4,069 posts

217 months

Tuesday 15th November 2022
quotequote all
monkfish1 said:
This is a question troubling me on my latest aquisition. Its been pointed in cement inside and out. The stone is harder than a hard thing. Utterley imperviois to moisture.

Ive primed myself to remove it all and repoint in lime, but there no evidence of damp. Yet. But it is stone with rubble in-fill. As you say, by any measure of logic, the lime mortar that is "in" the wall may well be wet. If it stays that way, it will degrade long term.

What to do????
You have two potential issues with a damp wall, decorative spoiling and potential to rot timber (floors and skirting). If neither of those are an issue then the damp is under control.

If a wall is unplastered you're highly unlikely to see evidence of rising damp, it will be controlled by evaporation.

As always, attention to the height of external ground levels is often critical.



Evoluzione

10,345 posts

244 months

Tuesday 15th November 2022
quotequote all
The first question to answer is how long has it been like that?
If it's been years and looks ok then make a decision based on that.

monkfish1

11,112 posts

225 months

Tuesday 15th November 2022
quotequote all
Evoluzione said:
The first question to answer is how long has it been like that?
If it's been years and looks ok then make a decision based on that.
Not long. It was repointed prior to being put on the market. Mainly because it looked pretty depressing having had no guttering for who knows how long. Fair bit of eroded mortar. Prioperly wet wall at the front.

So pointed and painted. Proper crap job though.

Inside, its never been plastered since built, but they repointed that too. Then did dot and dab insulated plasterboard. However, its completely dry in the 2 places ive accessed behind the plaster board. Longer term, the plaster board will be going.

Would have been a whole lot better left well alone. Would have been less work.

monkfish1

11,112 posts

225 months

Tuesday 15th November 2022
quotequote all
C Lee Farquar said:
monkfish1 said:
This is a question troubling me on my latest aquisition. Its been pointed in cement inside and out. The stone is harder than a hard thing. Utterley imperviois to moisture.

Ive primed myself to remove it all and repoint in lime, but there no evidence of damp. Yet. But it is stone with rubble in-fill. As you say, by any measure of logic, the lime mortar that is "in" the wall may well be wet. If it stays that way, it will degrade long term.

What to do????
You have two potential issues with a damp wall, decorative spoiling and potential to rot timber (floors and skirting). If neither of those are an issue then the damp is under control.

If a wall is unplastered you're highly unlikely to see evidence of rising damp, it will be controlled by evaporation.

As always, attention to the height of external ground levels is often critical.
Solid floor, no tiber to worry about. No plater either. Just insulated plaster board with a void behind. That will get removed.

Ground levels significantly lower outside.

monkfish1

11,112 posts

225 months

Tuesday 15th November 2022
quotequote all
Snow and Rocks said:
I wouldn't worry overly - by all means dig into the wall somewhere to check but when I turned an existing window into a door everything was bone dry internally even down to near ground level.

If you think about it the path for any water to soak up through internal lime mortar around many layers of almost impermeable rock is pretty tortuous even once it gets up through the typically huge foundation stones. Add in the fact that the cement based mortar is still somewhat permeable (just less so than lime) and any trapped water should still be able to escape.
Yes, i thinking of drilling a couple of holes in the mortar lines and seeing what comes out.

If its dry dust, happy days.

If its like my current house, drilling holes just produced a damp slurry!

Snow and Rocks

1,901 posts

28 months

Tuesday 15th November 2022
quotequote all
Out of interest where is the house and what is the stone?

monkfish1

11,112 posts

225 months

Tuesday 15th November 2022
quotequote all
Snow and Rocks said:
Out of interest where is the house and what is the stone?
Mid wales. Stone, not sure. Locally, its called river stone, no doubt because it came out of the river. Some of them have white streaks running through them. Not sure what the technical term is?

Evoluzione

10,345 posts

244 months

Tuesday 15th November 2022
quotequote all
monkfish1 said:
Evoluzione said:
The first question to answer is how long has it been like that?
If it's been years and looks ok then make a decision based on that.
Not long. It was repointed prior to being put on the market. Mainly because it looked pretty depressing having had no guttering for who knows how long. Fair bit of eroded mortar. Prioperly wet wall at the front.

So pointed and painted. Proper crap job though.

Inside, its never been plastered since built, but they repointed that too. Then did dot and dab insulated plasterboard. However, its completely dry in the 2 places ive accessed behind the plaster board. Longer term, the plaster board will be going.

Would have been a whole lot better left well alone. Would have been less work.
Yes I can see why the Spider senses are tingling. Lots of detailed pics would help, aside from that it's your call to act now and hack it off, or take a risk. This Winter will be the decider if someone is living in there.

monkfish1

11,112 posts

225 months

Wednesday 16th November 2022
quotequote all
Evoluzione said:
monkfish1 said:
Evoluzione said:
The first question to answer is how long has it been like that?
If it's been years and looks ok then make a decision based on that.
Not long. It was repointed prior to being put on the market. Mainly because it looked pretty depressing having had no guttering for who knows how long. Fair bit of eroded mortar. Prioperly wet wall at the front.

So pointed and painted. Proper crap job though.

Inside, its never been plastered since built, but they repointed that too. Then did dot and dab insulated plasterboard. However, its completely dry in the 2 places ive accessed behind the plaster board. Longer term, the plaster board will be going.

Would have been a whole lot better left well alone. Would have been less work.
Yes I can see why the Spider senses are tingling. Lots of detailed pics would help, aside from that it's your call to act now and hack it off, or take a risk. This Winter will be the decider if someone is living in there.
Wont be doing anything like that for at least a year, maybe 2. Want to get a good feel for whats going on. I may just do one area inside and out to see what happens.

Evoluzione

10,345 posts

244 months

Wednesday 16th November 2022
quotequote all
monkfish1 said:
Evoluzione said:
monkfish1 said:
Evoluzione said:
The first question to answer is how long has it been like that?
If it's been years and looks ok then make a decision based on that.
Not long. It was repointed prior to being put on the market. Mainly because it looked pretty depressing having had no guttering for who knows how long. Fair bit of eroded mortar. Prioperly wet wall at the front.

So pointed and painted. Proper crap job though.

Inside, its never been plastered since built, but they repointed that too. Then did dot and dab insulated plasterboard. However, its completely dry in the 2 places ive accessed behind the plaster board. Longer term, the plaster board will be going.

Would have been a whole lot better left well alone. Would have been less work.
Yes I can see why the Spider senses are tingling. Lots of detailed pics would help, aside from that it's your call to act now and hack it off, or take a risk. This Winter will be the decider if someone is living in there.
Wont be doing anything like that for at least a year, maybe 2. Want to get a good feel for whats going on. I may just do one area inside and out to see what happens.
If you can sit, monitor, watch what happens and act accordingly it's better than rushing in and making mistakes.