Resolving cold bridging issues in victorian terrace house Damp can be a major issue in the home. Find answers to questions or post your own here.

[Handy Dad]

Hi,
I have a Victorian end terrace house, the walls are solid brick and I am getting a build up of condensation on the inside of the outside walls resulting in mould growth. Would it be reasonable to line the walls with an insulation board so as to stop the cold meeting the warm air indoors?

[stoneyboy]

Hi handy dad,
If you fit insulated plasterboard it will just stop the wall breathing and will probably lead to an even wetter wall than you have at present. Have a look at the spacetherm breathable wall liner which may minimise the issue.
Regards S

[Handy Dad]

Hi stoneyboy,
I think this problem is condensation on the cold outside wall not penetrating damp. If I insulated it would that not stop it being damp? I understand what you are saying about the breathable membrane, I have seen a version that you can dot and dab gyproc over, is that similar to the one you suggested?

[stoneyboy]

Hi handy dad
No, if you insulate the wall with a non-permeable covering moisture will penetrate through joints and the perimeter and will condense on the cold wall. You must use a permeable covering and not make it non-permeable by painting with vinyl emulsion.
Regards S

[Handy Dad]

Hi stoneyboy,
Would this work, a semi permeable membrane like this https://www.drywallandfloor.co.uk/membrane_shop.htm covered by new gyproc?
Handy Dad.

[stoneyboy]

Hi handy dad,
I can’t find any reference in your link to the membranes being permeable.
Regards S

[Handy Dad]

You are right. This product was recommended by a damp proofing company. I will carry on researching.

[stoneyboy]

Hi handy dad,
Reviewing your posts I understand that you have a condensation issue.
Solving this will mean either increasing the ventilation or installing a dehumidifier. Lining the walls internally with insulation will not cure the problem.
Victorian houses were deliberately ventilated by air bricks or fireplaces in each room, so I assume yours are all sealed off.
Regards, S.

[Handy Dad]

Hi Stoneyboy,
This is my daughters and her partners house which I visited for the first time recently so I have not had much chance to inspect the issues in depth. I did notice that the air bricks on the end wall have been filled with building foam!! and the fire place to the lounge has been removed. The windows probably don't have trickle vents and I also noticed there is no radiator in the hall, stairs and landing. I will suggest they vent more and maybe look at increasing the heating system. Does that sound like a reasonable approach?
Handy Dad.

[stoneyboy]

Hi handy dad,
Increasing ventilation especially on dry days would be a good start. Probably be cheaper to buy a smart dehumidifier and run this 24/7 rather than modifying heating system.
Regards S