Advise. Plastering

[Annabel]

Hi,
Just some advice please. I recently moved into a middle terraced brick house that was built 1890-1900. I am in the middle of renovating and decorating the house. I have attached photos of the middle living room downstairs. I ideally would like to paint the walls however the walls seem to be in quite bad condition- blown plaster in places and feel damp to the touch. I have had a new damp proof course (about 2 months ago) and I am opening the fireplace back up to install a log burner in December. I am not sure how to go about decorating the walls. I know ideally the best course of action would be to get the walls replastered with lime plaster however this is very expensive and not in my budget currently. Does anyone have any advice in what I can do with the walls that will allow me to make them look better/ and what is causing the walls to still feel damp? Previous owners papered them with very thick vinyl (which I have partially stripped off). Was thinking about getting them skimed with gypsum plaster/ or wallpapering them (then painting). However I have now read that this will not allow walls the breath and will damage the house ? Is there such thing as breathable wallpaper that can be painted but also thick enough to cover over the blown plaster? Or would be be better getting walls skimmed with gypsum ? (Cannot afford lime). Advise please, many thanks.

 

[paulc]

You probably won't like what I have to say, but.... Drilling holes in the walls and shoving those magic beans in will do little to stop damp. If the intent was to create some form of DPC it is way too high. Should have been 6" or so lower so that it is below the level of the joists. I fear you have wasted a good chunk of money.
Looks some of the walls already have gypsum plaster on them, the chimney breast in particular - Putting a stove in there will heat the wall up very nicely. Trouble is, gypsum cracks and flakes off when subjected to temperatures above 50°C. I regularly see wall temperatures well over 100°C just above my stove. A large mantle will deflect some of the heat, but there will also be quite a bit being soaked up from the flue. You can get heat resistant plaster from a company called Vitcas. It is a cement based product, so to call it a plaster is a little misleading. Lime will also withstand high temperatures, so you might want to take another look at the stuff.

 

[Toby Newell]

Check gutters. Check drains. Check run off. Check exterior ground level. Doing this in a torrential downpour can be instructive. Check foilage. Check air bricks for obstruction, these should be 75mm above ground. Those are your top checks. DPC generally should be 150mm from exterior ground level.

The universe doesn't care what your financial priorities are, physics is physics.

Cover blown plaster with wallpaper?

Best effect, hack off gypsum, lime + breathable paint, next best effect, hack off gypsum, re gypsum + breathable paint, you might be able to scrape off paint and skim (looks like you have paint direct to plaster)

Doing anything on top of painted plaster is futile if its vinyl based.

Gypsum is somewhat breathable contrary to legend, as is traditional starch based wallpaper adhesive and, obviously lining paper, so breathable paint on top of that will help.

The issue is each layer has a certain cumulative 'resistance' that reduces permeability. Hence painting direct to plaster cab be etter without lining (depending on coats)

Remember, your plaster or paint isn't causing the damp, something else is, it is just not allowing it to evaporate.

Hopefully your dpc was done properly and this helps.