Panorama - damp/mould

[Harry Bloomfield]

You wouldn't believe the amount of condensation she has been removing from windows and walls. I reckon another couple of weeks and we'd have mushrooms growing out of the skirting boards. Based on that, I can see how it doesn’t take long for mould to appear in a house with very little ventilation, more so if you are hanging up washing to dry indoors.

Twp of us, in a mid-1950's, three bed semi. We never open the windows in the colder months, we have baths every other day, cook every day, do the washing - yet there is absolutely no mould here. Why?

Well - I insulated the place, as best I could, CWI, DG, modern doors. The internal heating is set to never fall below 14C as a minimum; we have an automatic extract fan in the bathroom; cooking we have lids on pans, and always run the extract cooker hood; there is a total ban on drying any clothes in the house. Without those measures, the CWI and DG, would count for nothing, and mould would be rife.

On TV, there was yet another tenant, complaining loudly, about mould all over the home, and the council landlord, doing nothing about it. She moved into the property 12 months ago, it was clear of mould then. 12 months later, there is mould everywhere, and council doing nothing, apart from offer advice. There were obvious signs of clothes being dried indoors, cooking without lids, or ventilating the steam. Window frames, covered in black mould, on the ceiling you could see the lines of the joists, in the black mould, on the ceiling. Landlords fault, absolutely not.

Some people are just not fit to be in control of a property.

 

[noseall]

Twp of us, in a mid-1950's, three bed semi. We never open the windows in the colder months, we have baths every other day, cook every day, do the washing - yet there is absolutely no mould here. Why?

The idiosyncrasies of condensation production can never be explained or rationalised with a one-size-fits-all answer. It is true to say that a poorly insulated/ventilated, multiple occupied house in the colder months WILL produce large amounts of the stuff.

One thing is for sure - the better a home is insulated - the better it will fare against condensation.

 

[Vinty]

One problem these days is that some houses can be overinsulated and not enough ventilation.
Doors and windows are sealed units ,modern roofs need vents ect.

 

[noseall]

One problem these days is that some houses can be overinsulated and not enough ventilation.
Doors and windows are sealed units ,modern roofs need vents ect.

All modern (building) designs are produced with passive and mechanical ventilation in mind.

If you took a modern well built/designed modern house, with robust latest insulation and the same for ventilation and occupied it with a large family for a period, over a cold snap and did the same for an older house with none of the above - the older house would fare worst, obviously.

You could add ventilation (alone) to the old house and make a slight difference. You could add insulation (alone) to the old house and virtually wipe out the mould/condensation issues completely.

Windows will always be an issue so having ventilation is a must.

 

[transam]

Speaking of insulation

Lady we work for is having to spend thousands of £ on replacing / repairing her roof

She had that spray foam insulation sprayed in her loft coated all the tiles etc afaik had a grant to pay for it

Total disaster

 

[Harry Bloomfield]

One problem these days is that some houses can be overinsulated and not enough ventilation.
Doors and windows are sealed units ,modern roofs need vents ect.

Yep, the more sealed up, and well insulated a house becomes, the more important it is, to have properly planned ventilation, plus the ventilation used.

 

[Vinty]

Speaking of insulation

Lady we work for is having to spend thousands of £ on replacing / repairing her roof

She had that spray foam insulation sprayed in her loft coated all the tiles etc afaik had a grant to pay for it

Total disaster

That stuff should be banned.

 

[Harry Bloomfield]

That stuff should be banned.

I understand, it works just great in the US, but with different roof design. It crossed the pond, and the installers here miss-sell it as fix-all a solution for the UK's very different issues.

 

[noseall]

Yep, the more sealed up, and well insulated a house becomes, the more important it is, to have properly planned ventilation, plus the ventilation used.

Yes, it’s called passive ventilation and has been designed into houses for decades, ie since double glazing became popular.

 

[Ihavenojob]

That stuff should be banned.

Why? It works, as long as it's installed by the letter. My daughter had it in her old house, mortgage company did the survey-not a problem, but when she went to sell it about 2 years later, buyers mortgage surveyor said it was a no no. Funny thing was, it was the same mortgage provider, just a different surveyor..

 

[Vinty]

Why? It works, as long as it's installed by the letter. My daughter had it in her old house, mortgage company did the survey-not a problem, but when she went to sell it about 2 years later, buyers mortgage surveyor said it was a no no. Funny thing was, it was the same mortgage provider, just a different surveyor..

Years ago , the company I worked for sent us to replace a lead valley which was supposed to be leaking.
Stripping out the slates covering the old lead Valley should have been straight forward, but because the roof space had been sprayed with this foam crap , the slates were all stuck together, we ended up breaking a lot of slates unnecessarily..
Getting it reslated was a bollix as well.
Turned out the lead Valley itself wasn't leaking at all, the damp was caused by condensation caused by the spray foam itself.

 

[robinbanks]

condensation caused by the spray foam itself.

 

[noseall]

Turned out the lead Valley itself wasn't leaking at all, the damp was caused by condensation caused by the spray foam itself.

The consequence of spray foam and any subsequent condensation can only be attributed to the stifling of air flow as the foam itself is insulative.

How the foam 'caused' it in your instance is a bit baffling....?

The main issues are the fact that it is sprayed directly onto non-membrane roof tiling and that it can mask the fact the tiles are leaking etc.

 

[martygturner]

It does make me question the memory of people, just a couple of years ago the same people decrying the use to trickle vents above windows and doors are now extolling the virtues of ventilation, still better late to the party than never arriving....

You cannot circumvent thermodynamics.. equilibrium of energy stores will always happen, insulation without vapour control is mostly an exercise in shifting the problem somewhere else, the loft, under the floors, somewhere hidden.

 

[Brigadier]

The consequence of spray foam and any subsequent condensation can only be attributed to the stifling of air flow as the foam itself is insulative.

How the foam 'caused' it in your instance is a bit baffling....?

The main issues are the fact that it is sprayed directly onto non-membrane roof tiling and that it can mask the fact the tiles are leaking etc.

And stops the timbers of the roof structure breathing, leading to rot.