Sandstone cellar

[MarkGee]

Hi all,

 

I've got an interesting damp issue and I'm hoping someone might have some advice for me.

 

I have a property where the cellar is carved into the sandstone bedrock and around 1 -2 meters of the ground floor walls are also carved out of the rock. The sandstone is incredibly porous so the air is damp but I also get water seeping out onto the steps into the cellar.

 

Any advice on how to tackle this? I don't want to put a dpm over the walls, as I'd like them cleaned up and exposed.

 

I had what is probably a stupid idea. If I  cored a 32mm wide hole into the wall by the steps and slid in some 32mm waste pipe, would the water take this easy route? I could plumb that into a drain. Other that that, all I can think of it good ventilation and a sump.

 

Cheers

M

[Russell griffiths]

You are not solving this problem and keeping that stone exposed. 
not unless you dig down outside and tank it out there. 

[markc]

So you have a house build over a cave.. quirky and an interesting feature but not very practical.

you are never going to stop water coming in and trying to “train” it into going where you want is unlikely with sandstone.

if you add a non permeable floor then you will get a puddle that drains back through the walls once the water depth is high enough.

your options are really leave it as is, or fully tank and drain to a sump and pump.

[Mr Punter]

I would consider just treating it as a crawl space, closed off from the floor above.  You could maybe put in a hatch for access.

[MarkGee]

11 minutes ago, Mr Punter said:

I would consider just treating it as a crawl space, closed off from the floor above.  You could maybe put in a hatch for access.

Unfortunately that wouldn't be practical due to the usage of the building. The front of the cellar has no issues as that is brickwork from all the tunnels etc in the area. You can see from this image that it's brick on the left but the sandstone starts just after the chimney breast (behind the block work), and steadily gets higher as you go towards the back of the building. So on the ground floor, the floor joists at the rear are sat directly on top of solid sandstone.

[MarkGee]

46 minutes ago, Russell griffiths said:

You are not solving this problem and keeping that stone exposed. 
not unless you dig down outside and tank it out there. 

There's an adjoining building unfortunately. 

[saveasteading]

If you want to keep the sandstone for interest or heritage, then you are limited. A sump and pump, forced ventilation, and dpm the floor above.

 

If the stone can be concealed then there are sheet  products made for basements.

[MarkGee]

34 minutes ago, saveasteading said:

If you want to keep the sandstone for interest or heritage, then you are limited. A sump and pump, forced ventilation, and dpm the floor above.

 

If the stone can be concealed then there are sheet  products made for basements.

Yeah, I want it exposed for a bit of both of those reasons. It's a retail unit in a conservation area and I'd like it to be as close to what it originally was as possible.

 

The previous owners had covered the walls on the ground floor with what looks like a skim of concrete and a dpm but it just moved the damp elsewhere. 

 

Any chemicals worth considering or just hefty ventilation and a pump?

 

Thanks

[saveasteading]

No magic chemicals I know of, and most would alter the stone.

 

Is it a flat or sloping area? Ie where is the water coming from? Does it vary seasonally?

[MarkGee]

47 minutes ago, saveasteading said:

No magic chemicals I know of, and most would alter the stone.

 

Is it a flat or sloping area? Ie where is the water coming from? Does it vary seasonally?

I just knocked this up in excel. So this is side on. I imagine it's rain water hitting the sandstone on the road above/any damaged drains.

The wetter the weather, the worse it is.

[saveasteading]

That's superb info.  It might be wetter if there was no road, because that is a lot of hillside collecting rain.

Are the other storeys dry, or you can't tell because they are tanked/ covered?

 

You need people from Edinburgh for this. There are tower blocks from the 1800s with 9 storeys above ground, facing downhill, fewre facing uphill,  and into basements. Sandstone too.

 

Google Earth: West Bow, Edinburgh

 

 

That's the good news.. they lasted a long time.

 

[MarkGee]

35 minutes ago, saveasteading said:

That's superb info.  It might be wetter if there was no road, because that is a lot of hillside collecting rain.

Are the other storeys dry, or you can't tell because they are tanked/ covered?

 

You need people from Edinburgh for this. There are tower blocks from the 1800s with 9 storeys above ground, facing downhill, fewre facing uphill,  and into basements. Sandstone too.

 

Google Earth: West Bow, Edinburgh

 

 

That's the good news.. they lasted a long time.

 

I believe the back wall is tanked in some way behind a stud wall. I've seen a portion of it when ripping out other parts. 

 

Some good news is appreciated!