1910 semi issues

[Shift]

My daughter bought a 3 bed 1910 semi 2 years ago which I've done a fair bit of work on, drafty windows/ doors insulation etc but it is still a cold house and suffers from slight mould. I know this is due to condensation on the inside of the external walls which I'm fairly sure don't have a cavity so need insulating.
The house has had external insulation on the gable end by previous owner but the coating on it is bubbling up in many places so I guess moisture maybe penetrating it and not helping much.
The front room was very cold as it had a cellar beneath so I put 100mm of kingspan in the floor joists which did improve things but not as much as I'd hoped.
The loft has been converted to a bedroom and the stairs are in what would have been the 3rd small bedroom. The floor has kingspan in it and there is kingspan in between the roof joists/ ceiling so well insulated. The room still feels fairly cold but this must be down to there being no heating up there so will be adding radiators soon.
As for the condensation issue in the bedrooms I plan to remove the plaster on the inside of the external walls and add insulated plaster board, hopefully 50mm will be ok as they don’t want to loose too much space, will this be enough and solve the condensation issue?.
Can anyone offer any more suggestions on what may help to make this old house warmer. Tia.

 

[endecotp]

The loft has been converted to a bedroom and the stairs are in what would have been the 3rd small bedroom. The floor has kingspan in it and there is kingspan in between the roof joists/ ceiling so well insulated. The room still feels fairly cold but this must be down to there being no heating up there so will be adding radiators soon.

“Fairly cold” in the loft despite zero heat input sounds like a good result to me - I’d expect it to be “absolutely baltic”.

Can anyone offer any more suggestions on what may help to make this old house warmer. Tia.

Well actually having some heating, and turning it on, would be a start. Do they have the heating on? What is the thermostat set to?

 

[^woody^]

It's not very wise to try and deal with condensation issues with isolated changes. You need to know what is actually causing it - the building or the people in it, and deal with issues in combination. You certainly should not be thinking in terms of putting "x" amount of insulation on a wall and hoping for the best.

External and internal wall insulation is a massive cause of internal condensation and mould issues, if it is done without proper consideration of ventilation and heating.

If the EWI render is defective and water getting into it, the cooling effect of that is not only making the insulation ineffective but is potentially a cause of internal condensation - so adding insulation elsewhere may be pointless.
EWI often has a long warranty, check that first and rule the render out as a factor.

Consider occupancy, usage, heating and ventilation patterns and how might excess moisture vapour be created and dealt with. Look at some of the condensation reduction guides published by councils and housing associations.

Priority physical measures would be ventilation and heating - including use of them. This may include installation of a positive pressure ventilation system, which would remove the need for internal wall insulation and all that expense and upheaval.

 

[Shift]

“Fairly cold” in the loft despite zero heat input sounds like a good result to me - I’d expect it to be “absolutely baltic”.



Well actually having some heating, and turning it on, would be a start. Do they have the heating on? What is the thermostat set

“Fairly cold” in the loft despite zero heat input sounds like a good result to me - I’d expect it to be “absolutely baltic”.



Well actually having some heating, and turning it on, would be a start. Do they have the heating on? What is the thermostat set to?

No experience of converted lofts so don't know what to expect, just thought as other have said shouldn't be as cold as it is. It is well insulated as far as I can tell but as said no heating other than a electric portable rad.

Of course heating is on @ 21' but like a lot huge bills are a worry.

 

[Shift]

It's not very wise to try and deal with condensation issues with isolated changes. You need to know what is actually causing it - the building or the people in it, and deal with issues in combination. You certainly should not be thinking in terms of putting "x" amount of insulation on a wall and hoping for the best.

External and internal wall insulation is a massive cause of internal condensation and mould issues, if it is done without proper consideration of ventilation and heating.

If the EWI render is defective and water getting into it, the cooling effect of that is not only making the insulation ineffective but is potentially a cause of internal condensation - so adding insulation elsewhere may be pointless.
EWI often has a long warranty, check that first and rule the render out as a factor.

Consider occupancy, usage, heating and ventilation patterns and how might excess moisture vapour be created and dealt with. Look at some of the condensation reduction guides published by councils and housing associations.

Priority physical measures would be ventilation and heating - including use of them. This may include installation of a positive pressure ventilation system, which would remove the need for internal wall insulation and all that expense and upheaval.

Thanks for the response, I like to find real solutions to the problems so all very helpful. I'll be doing all the work as they can't afford professionals just need a steer on how to tackle all these issues.

 

[endecotp]

Can anyone offer any more suggestions on what may help to make this old house warmer. Tia.

Of course heating is on @ 21' but like a lot huge bills are a worry.

OK, so is it reaching 21 degrees? Is the aim to make it warmer, or to reduce bills? Or to resolve the condensation? You need to be clear about what your objective is.

Standard question: how do they dry washing? Are there extractors in the bathroom and kitchen, and do they use them?

 

[Shift]

OK, so is it reaching 21 degrees? Is the aim to make it warmer, or to reduce bills? Or to resolve the condensation? You need to be clear about what your objective is.

Standard question: how do they dry washing? Are there extractors in the bathroom and kitchen, and do they use them?

Yes it reaches 21' no problem but takes a while. I think this is because it doesn't retain the heat. The previous owner who was an architect attempts at insulating the solid walls haven't been successful but you'd think he would know what he's doing.
Kitchen extractor hood is always used, fitted humidistat bathroom fan 18 months ago, that runs for about 20 mins once normal humidity is detected in winter.
They now have an electric clothes airer, some radiator racks and use a dehumidifier when drying clothes which collects a fair bit of water.
Objective is to make their home warmer, more comfortable in winter and eliminate any chance of health issues associated with mould. The mould is not horredous but it is in the corners of the bedrooms behind wardrobes so we would like to stop that coming back in winter.

 

[stevie888]

The previous owner who was an architect attempts at insulating the solid walls haven't been successful but you'd think he would know what he's doing.

An awful lot of architects produce lovely drawings full of difficult/expensive details and have little idea of practical building.