Cavity Wall Insulation

united4ever

I am debating whether to have CWI done. Had the Mark Group round last week who drilled a few holes in my wall before saying they could do it with a grant (no cost to me) which I agreed and I now have 2 weeks if I want to cancel. I have done the research a bit late but read some horror stories on the internet with damp.

I am in a moderate zone for wind driven rain not in an exposed position and the house is a 60s barratt home. From the survey when i bought the house last year it states about the walls: The internal walls are a combination of solid block work, lightweight timber stud partitions with plasterboard and skim finish.

The EPC listed cavity wall insulation as one of the recommended steps but not sure how much weight to give to that recommendation.

These government contractors get paid only if they can do it I gather and I heard when they do the job there are time pressures. So they are incentivised to say yes they can do it and to do it as quickly as possible which leaves me worried they will do a botch job. When I asked what material they used they said it's called superfill 40 from a company called knaus:

http://www.knaufinsulation.co.uk/en-gb/products/blown-mineral-wool/supafil-40-cavity-wall-insulation.aspx#axzz3SBp3x3Ha

says it's moisture resistant but not sure how they measure that.

Anyone else know this material? or have any insight on whether my situation is suitable for CWI?

sk240

I would see if you can get the poly beads instead, where the fibre stuff can bridge the gap can cause damp to cross from the outside wall to the inside wall.
The poly beads are waterproof, and if you get any ingress from the outside, it allows the water to flow down the cavity instead of across it.
I have the poly beads, and they have made a massive difference to my running costs (3 bed, only £22 per month in gas :-)

united4ever

Thanks, do you know if this poly bead system is available for free (via the grants) that these types of contractors offer? or would I be required to fund the full cost?

WestonDave

It was available free when I had mine done a while back (probably about 8 years ago to be fair). Can't say we've had any problems that seem to be related to it - bit of condensation due to lack of ventilation (now solved) but that wasn't anything to do with the cavity wall insulation and was worse before it was done. It is however less popular with installers so you have to search for the installer and possibly get them to source the grants etc.

Vimes

I remember several years ago getting a quote for cavity wall insulation (CWI), as it was not free then, but we did not go ahead.

Fast forward to about five weeks ago and we got a knock on the door from agents pushing CWI through the Mark Group.

Their assessment seemed more based on whether we have a cavity and thus meet the requirements rather than was it suitable for our property - exposed gable end and we do get wind driven rain to that side of the house.

The surveyor who called around two weeks later was employed to provide an energy report and a recommendation for the installation.

Yesterday, after they had previously cancelled on the day the actual installation with no notice, they turned up to do it after I complained several times to them over the phone.
Understanding that we had a lot to sort out due to an adjacent garage needing emptying as they would need to drill internal. Also the loft needed to be cleared as some of that would need internal drilling.

So the team arrived but then refused to do the job as they said the job should never have been arranged without scaffolding - grr...!

So now they are looking to cost me up for scaffolding if I wish to have this done.

They use a fibre type product (some have noted it as being like blotting paper but that might be not related to the one linked by the OP) on the install which seems pretty common.

But I am now rethinking the whole idea of having it fitted or not and the more that I read the less confident I am that unless the company do it right and use a suitable filler there could be problems post installation. Even if they do tick those boxes there can still be issues with certain properties.

Our next door neighbour in their detached bungalow have started to have a few damp patches on their walls which might indicate poor filling etc but have had a very poor response from the company who fitted it on helping to asses their problem.

Whilst for a lot of people it does seem that CWI has made a positive difference to their energy bills and the installation etc has gone well. Others have not faired so well.

I am just not to sure whether to proceed or not. Reading up a little over at the Which site, and others, hasn't convinced me either that CWI is as trouble free as the first two agents tried to lead me to believe.

united4ever

Vimes, sounds like you are as unsure as me. Let me know the consensus of Which. Our property does not really have much exposure to wind driven rain although it in in the 'moderate zone' on that map they use. Lived in a flat before that had mould and so far the new house seems nice and dry....would hate to mess that up. Part of me thinks don't do it now but wait a few years to see what happens to the thousands of houses getting CWI in this way.

System

The Mark Group did my cavity wall insulation. I don't regret having it done. The house is warmer but you do have to realize the house doesn't 'breathe' like it used to. Ventilation when your cooking is important. I have moisture absorbers on all the window sills over winter.

Vimes

I am having some difficulty finding a sense of balance on whether what I am reading is a fair representation of what is happening with properties that have had CWI for a number of years, as they seem to be too few as yet for me to make a judgement. Reading of the issues some are having and then paying 2k-3k to get it removed, with no help from the CIGA warranties etc is not promising.
The desire to reduce the carbon footprint and energy consumption by the Government is commendable but the actual suitability with certain properties for CWI and the standards of its installation can vary considerably.
To see the emergence of companies now specialising in CWI removal isn't too encouraging either...!

It is difficult for me to explain without you seeing our semi detached property. But f you did you would understand with the size of our front and back bay windows and no internal used living space with an external wall it makes me wonder just how much of a difference it would make for us against that of the uncertanty I feel of its installation. Even the surveyor suggested that we would save very little money on our heating bills due to our lifestyle and how we heat our home.

Putting a LID (let it develop) approach might well be for the best and whilst there is a finite time for one grant there often seems to be another scheme which replaces it sooner or later.

Our house is good with no condensation or damp problems, we use a dehumidifier and have adequate ventilation etc. Our heating bills are quite low for its large size - four bedrooms, three reception rooms etc.
I do understand that as peoples homes become more sealed then they do not adjust their living habits to introduce ventilation etc, that might also contribute to their problems when CWI is fitted.
I just don't want to create a problem which turns out to be bigger than the non-issue I didn't need to resolve.!

Reading things like this does not encourage me either...

Another problem is insulation sinking to the bottom of the cavity, leaving cold areas at the top of the house or below windows, ripe for mould growth. Insiders say this is often due to insufficient fibre being used – a common problem with contractors employed on bulk contracts claiming the government subsidy, but who are insulating up to five houses per day at a price of only £100 each, when a good professional job should take a whole day, and cost at least £500. (If you have had blown fibre cavity insulation, and you suspect that it has settled, leaving gaps, then you can check for this by drilling holes near the top of the bedroom walls and inserting a fishing weight on a piece of string.)

Seronera

The O.P. mentions his house is a 60s Barratt Home. In that case there is a very strong possibility it is a timber framed house. Before going ahead with CWI (which I generally support doing) its important he checks into the suitability of his house if it has a timber frame.

I'm not quite sure where to start, but any good qualified surveyor ought to know or the energy saving trust might offer advice or just Google it. I have nothing against Mark insulation they did my house in Lincolnshire just fine, but its wrong to expect their people to have the same level of expertise in construction as a qualified surveyor. In a perfect world they would of course, but I think you'd be best checking yourself just to be sure

davesmith9090909

I had damp, mould and condensation after a commission only salesman turned up and said my house was suitable for cavity wall insulation. A&M Energy Solutions installed it and it was later extracted as non compliant. CIGA were not interested and said the property was installed to standard and the condensation was my issue. Two independent reports said the CWI had to be removed and was the cause of the issues.

Be very careful and make sure you have the right property for it. Once they instal it they don't want to know when it goes wrong and don't think CIGA will help. I wrote to A&M Energy Solutions over 7 months and never received a letter back. I took them to court and they paid me off before the court date. This is what can happen if you are mis-sold - trust me you don't want this!

There needs to be a big change in this industry to stop non-compliant installations. I hear there are many complaints about cavity wall insulation but there is a lot of cover up in my opinion.

youtube.com/watch?v=otl_EAH-1K8

Furts

davesmith9090909 wrote: »

I had damp, mould and condensation after a commission only salesman turned up and said my house was suitable for cavity wall insulation. A&M Energy Solutions installed it and it was later extracted as non compliant. CIGA were not interested and said the property was installed to standard and the condensation was my issue. Two independent reports said the CWI had to be removed and was the cause of the issues.

Be very careful and make sure you have the right property for it. Once they instal it they don't want to know when it goes wrong and don't think CIGA will help. I wrote to A&M Energy Solutions over 7 months and never received a letter back. I took them to court and they paid me off before the court date. This is what can happen if you are mis-sold - trust me you don't want this!

There needs to be a big change in this industry to stop non-compliant installations. I hear there are many complaint about cavity wall insulation but there is a lot of cover up in my opinion.

youtube.com/watch?v=otl_EAH-1K8

It is good that you have a satisfactory outcome, but it would be helpful to mse Forum users if you could explain why your home was unsuitable for CWI.

I share your opinion of CIGA. This body cannot be differentiated from a snake oil sales person. Indeed, many snake oil sales people could teach volumes to CIGA staff on customer courtesy, good manners, customer service and professionalism. Bluntly put, CIGA is a cr-p trade organisation that exists primarily to protect the salaries of all the dubious people that work for it.