Cavity Wall Insulation - Any Disadvantages?

In article , LongYP writes

We had ours done some 9 years ago with no problems whatsoever:-)

None that we've had....

This does not answer your question, but before you get the work done contact your electricity/gas supplier. I have just had my property wall cavity and loft insulated free of charge. I must add that the loft was free because there was no loft insulation at all, otherwise, as my loft is above the X square metres, I would have had to contribute to the cost. The wall insulation would have been free whatever. It was a combination of Government grant and fuel supplier grant.

What build up of condensation? Is someone having you on?

The damn stuff falls out when you bang big holes in the wall.

|In article , LongYP | writes |>Looking for a little advice. My local council are providing Home Insulation |>Grants and we had a guy do a survey yesterday to do the loft and cavity |>wall. |>

|>I am just a little nervous about getting the cavity walls pumped full of |>insulation especially after reading about problems with build up of |>condensation. |>

| |We had ours done some 9 years ago with no problems whatsoever:-)

Non in 40 years.

LOL!

There are NO negatives. Get it done ASAP. You'll notice the difference immediately.

We had ours done many years ago so don't notice any difference but we've not been sorry.

Of course, we've never banged big holes iin the wall ...

Mary

Sorry to hijack, but related to this:

We wanted to get CWI a couple of years ago. Ours is a 1940s brick semi

- half of the original outside wall is now internal to an extension. We contacted the people, they came out and we've been told twice now that we can't have it.

The reason, apparently is that we have a one metre high stone section to the front wall - still a cavity, but stone all the same. They say they won't do it as they can't guarantee it for c30 years. Any suggestions?

The only other one I've ever heard of is when theres wiring in the cavity. If its already overloaded, insulation will make it hotter, and iirc the earlier foam bead insulation was incompatible with pvc. The damp issue comes in with some incompatible wall types, such as stone rubble and rattrap bond.

NT

Thanks for ALL the responses.

The condensation build up is considered to a genuine issue if you have log burners or open fires - the company said air vents would need to be put into the wall.

Overall though, sounds like it is the right thing to do.

Surely you already have air vents?

But condensation could be a worse problem without CWI, the walls would be colder.

Mary

"LongYP" wrote

My father-in-law had a 1960's semi done and it caused the cavity to bridge and damp to track through to his internal wall.

Phil

The advice is good. Your insulation options are solid insulation or battens/rockwool/drywall on the interior, or exteral insulation such as cladding etc.

NT

I can't get mine done because of health and safety issues, they wont go on my garage roof in case they fall off. And I ain't paying an extra £300 or £400 for scaffolding. Ron

I can't see how CWI can increase condensation. It should reduce it. Condensation occurs when warm moist air meets a cold surface. CWI means wals are warmer so the chance of condesation is less. Condensation can be a problem when windows and doors are replaced and this may be carried out at the same time. The blame could then be wrongly placed on the CWI.

John

We had CWI done this summer and we noticed that very night that all the major draughts we had where gone, we haven't had probs with condensation but I guess that the reduced 'ventilation' due to the draughts up the cavities/under floor/around windows etc being stopped could allow the humidity to rise enough to cause condensation.

Downside seems to be that now it's warmer inside the spiders are getting enormous! one last night was too big to get down the plug hole in the bath using the shower.....can't stand 'em

Pete

Its not so much condensation, as water getting in to the cavity. If there is ingress, and its been falling all the way down and soaking out sub floor level into brickwork, and you then fill the cavity up. its likely to result in a sodden mess higher up.

As long as the house is sound, it will make a huge positive difference.

I've just had a quote of £285 for CWI for a 1939 gas heated semi from the HEAT project. This is £20 more than their website suggested.

I guess that this will be blown coated rockwool.

The fourth energy price increase in about 18 months from NPower finally blew my gasket. I've insulated everything else that I can do on my own, including loft, underfloor in the living room, and stuffed up all the gaps and air leaks viz the skirting, the windows, the CH pipes and the doors.

What kind of prices are others paying/have others paid? Don't want to get ripped off.

BTW I reckon if CWI does its job then its a much better rate of return on my investment than I can get by putting money in the bank ( i.e.5% ) so its an investment of sorts. I understand the savings could be something like

Andy.

I prefer a bath to a shower too.

Mary

SNIP

I paid £150 for a detached 3 months ago. Arranged through powergen fitted by The Milfold Group. This is a none benefits rate for all 4 walls with no vent adaptation needed, and they were happy to clamber about on the garage roof. I would start with your power company and check the price with them, and try other power company afterwards. As far as I understand it the power company have a duty to do something towards the environment, and putting extra discounts towards this is one thing they do.

I keep getting leaflets though the letter box offering discounted rates of

Back to the OP, I have noticed now the weather is colder a little more condensation.

Steve

So have them inject it from the inside. It just means you'll have some holes to fill and paint.

NT