plastering a cellar/basement

[Tom.]

1) I don't believe in sealing damp problems with non-penetrable membranes. I believe in the long term they cause far more problems than they solve.

2) Read my posts, you'll see I mentioned something similar.


I'm not an expert, but I do like to offer my (sometimes) misguided but well-intentioned advice. I'm just sick and tired of 'miracle' solutions being proposed for old buildings. If you have an old building, treat it as such, use the same materials now as were involved in its construction.

'Solid earth floor too damp' - how many times have I seen people recommend that waterproof membranes and tanking be used, all because some daft bint wanted a plush carpet in a house which for the last 150 years has had a bare floor and rugs, with good circulation. 'Condensation in my house because I installed DG everywhere' - oh right you need a dehumidifier then and a chemical DPC! Thats the twaddle. If you buy an old house, you should respect it, and not ruin it with ****ty plastic doors and windows, or replace the slates with tiles, or point it with cement, or fill the floor cavity with concrete, or knock all the plaster off and put plasterboard up.....

 

[shaggy]

I agree with some of what you said Tom but referring to this:

use the same materials now as were involved in its construction.

Imagine you've just got the scaffolding around your victorian chimney stack and you are about to renovate it. You find that you can just lift the bricks away, and that beautiful corbelled structure really need rebuilding and not repointing. My question is, what mortar mix are you going to use?

 

[martinemj]

in reply to tom,

you say to use traditional materials as were used in its construction .

so if we take this further we will come to the conclusion that the basement was never intended as a habitable room and was always a sort of sacrafical layer of the house.

you will never replaster a basement using limeplaster and stop problems



i agree with a hate of plastic windows and doors in old buildings though

reguards

martin

 

[doitall]

A plumbers view

I have seen a wall pushed over with the buildup of water from a spring where the inside was waterproofed.

A build up of water behind a wall will create several tonnes of pressure.

Water and damp should be treated from the exterior not after its penetrated the wall.

Also some buildings will crack and cause structual damage as they rely on moisture content, Cob houses for example.

Houses built on clay rely on moisture to stop the ground sub-sideing.

 

[Ruthstarley]

Hi! I know this is an ancient post but I wondered if opinions have changed?
We have a victorian 1920's mid terrace.I have decided to strip my dry cellar back to brick - it had been boarded over with some awful plywood sheets. Behind was stud work and the bottom 2foot of wall was rendered with cement and wrapped in plastic sheets and the rest painted withlime wash seemingly 1000's of times(?) The battons were generally dry when I peeled it back but there was an awful musty smell and the render was dark and damp. Since stripping it back everything it seems dry and super dusty!! I want to use this space as a gym and laundry room not it only needs to be dry-ish. I'm thinking of soda blasting the walls clean, adding a heat exchange unit and boarding all the pipes and cables into the cavity between the floor joists. My question is - as there is a dividing wall between the rooms can I lime plaster it both sides? Will I struggle with rising damp still as I have a concrete floor but without membrane. Mostly I would like to break up the bare brick as it is quite dark with a fresh white wall to help with the light. Also any thoughts on silicate primer to help stablise the bricks and mortar to reduce dust?
Your thoughts would be great!!!!

 

[noseall]

There is no magical panacea for subterranean structures. They are either built correctly from the outset, i.e. with tough waterproof membranes on the outside preventing moisture etc or they end up being damp uninhabitable spaces.
There are retrospective (internal) remedies, but these are expensive and not always reliable. They require expert, diligent installers.
Using and storing gym equipment does not necessarily mean you need a bone dry environment. However, if that musty damp dusty flaky wall thing bothers you, then the cellar is not the place for you.

 

[Himaginn]

You need to decide if you are going to use breathable products to allow walls/floors to continue to breath, or products which seal the walls/floors to prevent damp coming through. Walls without a DPC/DPM will invariably have some damp in them.

Lime plaster allows the wall to breath. So any damp in the wall evaporates though the lime plaster. A lime wash finish is also unaffected, so you can tint the lime wash without any problems. But lime plaster/lime wash can also absorb damp if there are high levels of damp created by say, laundry, exercise, etc, whereas a non-breathable finish might allow condensation. Be careful about any other kind of finish on a lime plaster that it doesn't negate the breathability.
With gypsum based products, which should not be used on walls without DPC/DPM, the walls do not breath. If you're going to seal the wall to prevent damp, use a cement/sand product, possibly with a waterproofer. I believe Sika products are good, but not cheap.

So beware of what products you use on the walls or floors. You either want to seal in the damp or allow it to continue to breath. I would suggest a choice based on current amounts of damp and proposed usage, i.e. relatively dry and your proposed usage, I'd go lime plaster route. But a more sedate habitable room, such as office, playroom, with higher levels of damp, I'd be looking to seal in the damp.

I believe a diluted coat of PVA will not adversely affect the breathability and will reduce dustiness of the surface. A lime wash will serve the same purpose.
Decent amounts of ventilation, which should be present in a gym/laundry room anyway, will help to keep Relative Humidity low, i.e. carrying away moisture in the air which has evaporated form the walls/floors/washing.

Another point about the proposed usage as a laundry room, do you have sufficient drainage?

 

[Phil 638476]

I have a 200+ year old cellar, half of the cellar is sandstone walls with the original lime mortar, half of the cellar had been rendered in cement, the un-rendered walls are bone dry, the rendered walls were damp. The floors are stone flags laid on earth. The floors attract condensation and are damp unless I either run a dehumidifier and/or fan to circulate the air. I hacked off most of the cement render and the walls are now almost dry. I have repointed the walls with lime mortar and painted the walls with Earthborn clay paint. At some point I plan to take up the stone flags and put down a limecrete floor on top of foamed glass gravel. The whole space is now breathable and with the dehumidifier running humidity levels are similar to the main house and there is no damp (the cost of the dehumidifier is similar to the cost of running a fridge/freezer). I would therefore recommend the breathable option over sealing the walls every time.

 

[JohnD]

This thread is more than 3 years old.

It is very likely that it does not need any further discussion and thus bumping it serves no purpose. If you feel it is necessary to make a new reply, you can still do so though.