Hi - I have posted this to a Facebook post and got no response so am hoping someone may be able to help / advise me on here! Apologies for the long post!
We have replaced cement pointing with lime pointing (in 2020) and replaced gypsum plaster (which had a Newtonite membrane behind it) with lime plaster (in May 2024) and painted with Earthborn Claypaint (in July 2024). In November 2024 we noticed ‘dark patches’ appearing on the wall which got bigger and we put a dehumidifier in the room incase they were damp - whilst ensuring the room was ventilated (we have a humidity meter measure relative humidity in the room). The wall is a external wall and we have check that the guttering is all fine.
In April 2025 we cut out a small section of the plaster and the wall behind it (and the plaster) appear dry. The plaster that was cut out still has patches on it that look like damp but are obviously not (as it was removed from wall 3 months previously).
Below the picture rail was painted in Earthborn claypaint (green) and above was painted in Graphenstone Naturcolor paint (white). I have since spent many hours with a steamer and scraper trying to remove the paints.
We have replaced cement pointing with lime pointing (in 2020) and replaced gypsum plaster (which had a Newtonite membrane behind it) with lime plaster (in May 2024) and painted with Earthborn Claypaint (in July 2024). In November 2024 we noticed ‘dark patches’ appearing on the wall which got bigger and we put a dehumidifier in the room incase they were damp - whilst ensuring the room was ventilated (we have a humidity meter measure relative humidity in the room). The wall is a external wall and we have check that the guttering is all fine.
In April 2025 we cut out a small section of the plaster and the wall behind it (and the plaster) appear dry. The plaster that was cut out still has patches on it that look like damp but are obviously not (as it was removed from wall 3 months previously).
Below the picture rail was painted in Earthborn claypaint (green) and above was painted in Graphenstone Naturcolor paint (white). I have since spent many hours with a steamer and scraper trying to remove the paints.
- The Graphenstone paint above the picture rail came off easily
- The Earthborn claypaint came off easily in places (RH side of the wall in particular) but in other places it seems as though a chemical reaction has taken place and when scrapped the plaster comes away (the places that are dark in the original photos before I tried to remove the paint).
- Is the smell the plaster still drying to dry out (we left it 6 months to dry before painting) or is there something else?
- What do we do – the wall is now a mess – in some places the top coat (plus some of the lime plaster below) has come off, in some places the Earthborn paint is still there and in some places it’s all fine
- What can we do to the wall – can a plasterer just add another top coat to the wall to even it out where needed?
