Hi,
I've been informed by a builder that the cause of damp and subsequent mould in an upstairs bedroom is being caused by water penetrating through the brickwork of an external wall. A damp meter shows the wall to be damp. In addition, it was pointed out that the fireplace in the bedroom has been blocked (but easily rectified) and is thus reducing the natural ventilation in the room. The mould appears in all parts of walls that are external, i.e. internal walls are not affected. The recommendation was to either:
a) Remove all plasterwork and replace with water resistant base and replaster. Then in the summer coat the external wall with a transparent liquid silicon waterproof barrier. This option was suggested because I wanted to re-decorate the room soon, or,
b) Leave the plasterwork, coat the external wall (now) as per (1) and leave for 6-8 months for all moisture to come through to the inside. Potentially using de-humidifiers to speed up the process.
Option (a) is costly, distruptive and will ruin a period coving feature so I am reluctant to go down this road unless absolutely necessary.
My questions are:
1) Assuming I am not bothered about re-decorating just yet, and am considering (b), would sealing up the outside and letting moisture come through potentially cause problems in other rooms?
2) Is it advisable to do this work in the winter?
3) Has anyone else done this and has it been successful?
4) Is "liquid silicon" the correct treatment, i.e. are the other ways? Is this basically the Ronseal "does what it says on the tin" stuff or is the silicon better?
5) How long should the silicon barrier last?
6) Should air bricks be considered or should the fireplace/chimney do this? No other similar houses have air bricks except in the loft.
FYI - House is 1901, double glazed and has gas central heating.
I've been informed by a builder that the cause of damp and subsequent mould in an upstairs bedroom is being caused by water penetrating through the brickwork of an external wall. A damp meter shows the wall to be damp. In addition, it was pointed out that the fireplace in the bedroom has been blocked (but easily rectified) and is thus reducing the natural ventilation in the room. The mould appears in all parts of walls that are external, i.e. internal walls are not affected. The recommendation was to either:
a) Remove all plasterwork and replace with water resistant base and replaster. Then in the summer coat the external wall with a transparent liquid silicon waterproof barrier. This option was suggested because I wanted to re-decorate the room soon, or,
b) Leave the plasterwork, coat the external wall (now) as per (1) and leave for 6-8 months for all moisture to come through to the inside. Potentially using de-humidifiers to speed up the process.
Option (a) is costly, distruptive and will ruin a period coving feature so I am reluctant to go down this road unless absolutely necessary.
My questions are:
1) Assuming I am not bothered about re-decorating just yet, and am considering (b), would sealing up the outside and letting moisture come through potentially cause problems in other rooms?
2) Is it advisable to do this work in the winter?
3) Has anyone else done this and has it been successful?
4) Is "liquid silicon" the correct treatment, i.e. are the other ways? Is this basically the Ronseal "does what it says on the tin" stuff or is the silicon better?
5) How long should the silicon barrier last?
6) Should air bricks be considered or should the fireplace/chimney do this? No other similar houses have air bricks except in the loft.
FYI - House is 1901, double glazed and has gas central heating.
open the fireplace, heat the room , kill the mould with bleach solution, decorate with a specialised paint, see what happens.old houses gotta "breathe"
