Is Cavity Wall Insulation Worth Pursuing to Get Rid of Mould? Any othe Solutions?

Border_Collie_2

Our Kitchen and Bathroom both suffer from condensation and we are doing whatever we can to reduce the problem. The bathroom isn't so bad since we had it tiled and an extractor fan put in, any condensation left after a shower or bath disappears or is easily wiped off. The kitchen has a corner near the back door (low down is worst) that regularly turns mouldy, but the kitchen will be renewed in about 3 years time.
We have had the loft properly insulated by British Gas (grant from council), but they refused to insulate the cavity walls as they have a lot of mortar obstructions inside and they cannot give the usual 20 year guarantee. Their engineer advised us against getting any cavity insualtion as he said it might cause dampness inside. He also said that the cavity can be cleaned out....at great cost.
We are getting a completely new combi-boiler heating system installed within a few months, so the kitchen will be much warmer with a more powerful radiator, and I'll get an extractor fan installed near the cooker....will all this be enough to eradicate dampness, or is it still worth getting someone else to install cavity wall insulation?...without a long guarantee.
I'm tempted, when renewing the kitchen, to fill that damp corner with cupboards...to keep condensation off the cold walls.

Thanks for any help.

smcqis

Do you have an extracter fan in the kitchen say over the hob?

Candles_by_Lisa

We had to get a dehumidifier as our house is an older house and the bedroom walls were always damp, especially in the winter when washing needs to be dried in doors. It works great however we have been told that the problem with damp indoors is more down to ventilation than anything else. We have old double glazing and don't have trickle vents which seems to be the cause of our problems. We are intending to get trickle vents fitted but are waiting for the better weather to come in. You don't have to get your windows replaced as our window fitter says it's not a problem to fit vents to existing double glazing units.

HTH.

Lisa

2010

Border_Collie wrote: »

r....will all this be enough to eradicate dampness, or is it still worth getting someone else to install cavity wall insulation?...without a long guarantee.
I'm tempted, when renewing the kitchen, to fill that damp corner with cupboards...to keep condensation off the cold walls.
Thanks for any help.

I would say that BG gave you the best advice to avoid CWI and you are lucky that they did.
Some other installers may not have been so honest and just thought about the money.

Twice I have had the option of FREE CWI and after a bit of research and on balance decided it was not worth the risk of getting damp and condensation for the little benefit, if any, of installing CWI.

Google "CWI and damp" and you`ll find some horror stories.
All this so-called free installation (we all pay for it through higher energy bills) is to do with government greenhouse gas targets.
The energy companies have to spend millions on it to meet targets.
That`s why it`s "free".

The same applies to all these wind turbines that blot the landscape and now the latest gimmick

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smart meters.

Maybe others can help about your damp problems because after suffering it in a previous house, I know what a nightmare it can be.

Hejo

Agree with 2010 - there have been some horror stories about target meeting unethical insulation companies stuffing walls full of insulation where its not needed and leaving people with more damp issues! If you've been advised your walls arent suitable then I would take their advice and stay well away. The extractor should help, and this sounds patronising - not intended that way - but open the windows as much as you can. Also have you tried damp proof/kitchen paint? That may help.

Good luck!

cyclonebri1

The answer is ventilation rather than insulation, coupled with better heating.

Get rid of steam at source, ie cooker hood extractor and I think most importantly buy a set of lidded pans, it's amazing how much condensation they prevent.

There is 1 other point that most people don't consider. Try using a fan, not an extractor but simply the type you would use mid summer. It may stop condensation forming at a specific point without throwing all your heat away.

Sounds like the new kitchen will resolve most issues anyway.

And just to add to the earlier bit. I had a real problem with fitted wardrobes in the corner of a bungalow, any leather would mould and so would anything that touched the back. Removing them and insulating behind with 2" of polystyrene didn't cure it, what did was putting vents in the lower kick boards and the base of the units and then a small extractor in the top out of sight. Ran it a few hgours a day off a timer.;)

keystone

cyclonebri1 wrote: »

The answer is ventilation rather than insulation

Couldn't have phrased it better myself.

Cheers

Border_Collie_2

Thanks for the replies and tips everyone, much appreciated.
A cooker hood will be installed when we renew the kitchen and get a new cooker, but in the meantime I'll get an extractor fan fitted nearby, although we always open the window when cooking. A new heating system and radiator to replace the old one that rarely got hot should help as well.
Thanks particularly for the advice on CWI, it was something that neighbours suggested was worth doing, but I was uncomfortable with it after the British Gas surveyor advised against it. I did have a look through his wall probe / scope and the original brickies have left a mess of overhanging mortar at joints. I wouldn't want to spoil a house that is very dry other than a little condensation in only 2 rooms....we run a dehumidifyer in the same room as our condensing tumble dryer and there's no mould in there, even though it's facing North.

macman

CWI won't reduce condensation. It will just mask the problem. Warmer walls just mean that the water won't condense on them so readily when water-laden air reaches them.
Warmer air holds more water vapour than colder air. The cure is to reduce the amount water vapour in the air by ventilation.

Tr1pp

hmmm, so you were told you have a lot of mortar obstructions within your wall cavity. Did they say if any of this mortar was also bridging the gap between your external and internal cavity wall? because this could be causing the problem you have in your kitchen an no amount of insulation would prevent that.

If the issue is that mortar is bridging the two walls then this will be an issue that would be pricey to put right (as you have said)

I would start with better heating and ventilation to try alleviate the damp.

another option would be to replace the existing plaster with an insulating plasterboard with a suitable vapour barrier (foil backed) to prevent the moisture getting through - can be expensive to buy this kind of plasterboard but if your redoing the kitchen in a few years then it may be worth it.

have you checked that its not rising damp due to a damaged DPM (assuming your kitchen is on the ground floor ofc)

Border_Collie_2

Tr1pp wrote: »

hmmm, so you were told you have a lot of mortar obstructions within your wall cavity. Did they say if any of this mortar was also bridging the gap between your external and internal cavity wall? because this could be causing the problem you have in your kitchen an no amount of insulation would prevent that.

If the issue is that mortar is bridging the two walls then this will be an issue that would be pricey to put right (as you have said)

I would start with better heating and ventilation to try alleviate the damp.

another option would be to replace the existing plaster with an insulating plasterboard with a suitable vapour barrier (foil backed) to prevent the moisture getting through - can be expensive to buy this kind of plasterboard but if your redoing the kitchen in a few years then it may be worth it.

have you checked that its not rising damp due to a damaged DPM (assuming your kitchen is on the ground floor ofc)

Thanks. There will be better heating as all the old back-boiler and old radiators are being replaced with new combi-boiler & rads. I've priced extractor fan installation (£200 - £300) and have decided to wait until we get the kitchen renewed (2 years) and have a cooker hood extractor. The mouldy corner is the opposite corner form the radiator and it's worst low down. under the bench, so I'm intending to put in cupboards under that bench to keep any warm moist air from reaching it.
I had a look through the surveyors camera / scope in a few spots and we didn't see any bridgeing of the gap, just very untidy joints not scraped clean. The only other cold (but not damp) room is on the same wall and as I cannot insulate inside the wall, I'm going to cover it internally with a polysytrene backed lining paper, just to make it warmer.