What to do with my cellar

Hoof Hearted · Post by **Hoof Hearted** » Sun Jul 12, 2009 5:04 pm

My house is 140 years old, is built from sandstone and has a cellar which is completely dry. There is a ventilation grille to the outside which provides good ventilation. The mortar used in the construction resembles plaster more than anything else and is crumbling quite badly.

I have an outbuilding at the back which was in a similar condition on the inside. I used a PVA wash to seal the stone and the mortar. It stabilised the mortar and looks really good.

I would like to use this PVA wash on the cellar walls, but I am wary that the cellar might only be dry because the stone and the mortar can currently breathe. If I seal it with PVA wash, I might get dampness building up behind the seal.

Is there anything I can seal the walls with that would still allow the walls to breathe? The stone is quite uneven. So plastering it would be quite a task.

Ian

DAZDEL · Post by **DAZDEL** » Sun Jul 12, 2009 5:40 pm

you could use a high quality mineral paint, brush the stone down first, then wash it with water, leave 24 hours, this will allow a bit of time for any salts to come to the surface.if they do, wipe off with a damp sponge, then paint. do not use pva. tbh if it was my cellar i would leave it alone as its looking after itself, breathing, and you have good ventilation

Hoof Hearted · Post by **Hoof Hearted** » Sun Jul 12, 2009 5:45 pm

Yeah I would do, except that the mortar is like gypsum and falling out onto the floor. I can't keep the place clean

DAZDEL · Post by **DAZDEL** » Sun Jul 12, 2009 6:15 pm

any chance of some pics, dont think it is gypsum

Hoof Hearted · Post by **Hoof Hearted** » Sun Jul 12, 2009 6:38 pm

Here's a photo. There are remnants of some whitewash that I need to get rid of yet. The mortar has all the properties of carlite browning. Some of it is falling out. All of it can be flicked out with a pencil. The outbuilding at the rear of my property was the same. It looks great since I sealed it.

DAZDEL · Post by **DAZDEL** » Sun Jul 12, 2009 7:21 pm

if its browning it will need to come off, but if someone said whats the picture of, i would of said granite. thats what it looks like. is there salts on the surface, and does it smell ?

Hoof Hearted · Post by **Hoof Hearted** » Sun Jul 12, 2009 7:53 pm

It's definitely sandstone. We dont have Granite in this part of the country. I didn't see any salts on the surface, but there are various stains and the remains of a coat of whitewash. There is no noticeable smell.

DAZDEL · Post by **DAZDEL** » Sun Jul 12, 2009 8:18 pm

so its definitely sandstone, can you scrape it back until the surface is sound, and then paint, pos another pic, but a long shot of the walls.

Hoof Hearted · Post by **Hoof Hearted** » Sun Jul 12, 2009 8:37 pm

The mortar is not sound. I noticed this years ago when I was working upstairs on the ground floor of the house. Although the external walls are all sandstone, the internal walls are all brick. But the same mortar was used. Bricks can simply be lifted out once they are exposed. The mortar turns to powder remarkably easily.

Most of the wall area is still covered in whitewash. The photo I posted shows one of the few areas that is mainly free from whitewash. So a more general photo would be of little use. Tomorrow I'm going to hire a needle gun to remove the whitewash.

thescruff · Post by **thescruff** » Sun Jul 12, 2009 8:58 pm

It is meant to be soft like that.

Forget what it is being a plumber, but it's like lime and stone dust, with bits of grit chuck in for good measure.

DAZDEL · Post by **DAZDEL** » Sun Jul 12, 2009 9:01 pm

let us know how you get on cheers.

darrenba · Post by **darrenba** » Sun Jul 12, 2009 9:46 pm

Given the age of the building it's highly likely to be lime mortar. As Scruff says it tends to remain sort unlike normal cement mortar.

Use of Traditional Lime Mortars