Cavity wall insulation

[clivejo]

My house has solid walls on the ground floor and cavity wall on the first floor.  I recently got a surveyor to check the insulation in the cavity wall and there is yellow fibre glass.  However over time I think the fibre glass has slipped down and is leaving the upper 2-3 foot of the cavity open, causing damp problems along the ceiling in any room with an external wall (warm air hitting cold wall).  I have asked several companies for a quote to get the cavity 'topped' up but once they hear its 'half full' they dont want to know, making excuses like our isolation might react with the fibre glass and cause damp at the interface.  The main one being it wont be guaranteed?!?

Is they anyone in the industry could explain this to me?

[biff]

Hi again Clivejo,
              They are obviously afraid to do the job and then have you chase after them for bringing damp into the house.The best thing to do is to put a camera down the cavity and see has their been an apron fitted.It would not surprise me in the least to find that there is a lead one fitted right round the house,If you go out side and look up the walls you might find the weepers,Little vents which take the water from the apron and direct it outside.this method was often adopted when adding an extra floor on to an old solid wall house.If there is an apron you can fill the cavity with bonded beads yourself.
                                      Biff

[A.L.]

hello,

reputable installers provide a 25yr third party guarantee from www.ciga.co.uk - re-filling a cavity like this would be outside the terms of the guarantee and therefore it would be worthless

there would be no reaction between the fibreglass and any of the fibre based insulants (mineral or glass wool) but there probably would be a difference in densities of the two materials, potentially liquid water could run down the inside of the outside leaf and cross the cavity at the interface, but since this is presumably not happening at the moment with the current arrangement it should not be a problem

the above link gives a large list of potential suppliers, one of whom may be willing to do the work

[clivejo]

hello,

reputable installers provide a 25yr third party guarantee from www.ciga.co.uk - re-filling a cavity like this would be outside the terms of the guarantee and therefore it would be worthless

there would be no reaction between the fibreglass and any of the fibre based insulants (mineral or glass wool) but there probably would be a difference in densities of the two materials, potentially liquid water could run down the inside of the outside leaf and cross the cavity at the interface, but since this is presumably not happening at the moment with the current arrangement it should not be a problem

the above link gives a large list of potential suppliers, one of whom may be willing to do the work

Yes, that's the website they all told me to go read, as if it was going to explain to me why it couldnt be done.  So its basically the guarantee is void if they do it?

[A.L.]

So its basically the guarantee is void if they do it?

- yes

Do you have any paperwork for the original install? there may/should be a guarantee for this, claim against this as 2.5 feet of compression in a single storey height suggests a faulty install (and what about under windows?). Even if you do not have paperwork contact CIGA and see if they have a guarantee against your address and proceed from there.
They might try and wriggle out of it because of the solid wall below but it is worth a try.

[odbob]

empty voids, whether just after the 'job done' or after a period of time, is no surprise to me, having inspected the cavities on two of my properties.
sloppy workmanship, bad practice, call it what you like, the industry seems riddled with it.
On one property, because I picked up the evidence quickly, I had my money back, although this wasn't the answer.
On the second property, too long ago now to do much about it, other than to warn other people.
If you want to know more about my experience, go to my web site www.myhomeenergy.co.uk

[clivejo]

I think its a bit over the 25 years now   Nothing I can do about it only DIY it or find some independent person (or in my mind a cowboy!)

[odbob]

Clive, diy is almost always best, at least you care

[clivejo]

*remembers the time he used a leave blower to suck up those silly wee beads, wonders if he switched the leave blower to blow would it fill the wall or just make artificial snow* 

[Ivan]

We had our house cavity insulated about 10years ago. Over the last few years, we've done various jobs on the house - replaced a few windows here and there, a boiler flue pipe through the wall, and taken the roof off for a warm-roof installation. In the process, we've noticed a lack of insulation in some areas, and what I presume is sagging leaving the top 12-18" of wall uninsulated.

In December, I contacted CIGA (as it has a 25year guarantee), and they told me to contact the installer. I contacted the installer, but they told me they can't help because they don't do that type of insulation any more. So I contacted CIGA again, and they replied by saying they've referred the matter to the insulation manufacturer and the installer to put right. The installer, obviously isn't interested, but the manufacturer sent someone to come and have a look. Having reassured him that I've seen it with my own eyes, so no point in trying to pull the wool over them, he was pretty up front, and having inspected the cavity he told me that it's not adequately insulated. He also claimed that the rockwood we had blown into the cavity cannot 'sag' and therefore the missing insulation at the tops of the walls is due to a lack of insulation being installed on day1. He's planning to arrange to have the walls re-insulated. They apparently drill holes and blow air into them to compact the insulation and then reinject new insulation into these holes. This was about 3weeks ago, but he did say it would take a few weeks to organise. We'll see what happens.

[clivejo]

He's planning to arrange to have the walls re-insulated. They apparently drill holes and blow air into them to compact the insulation and then reinject new insulation into these holes. This was about 3weeks ago, but he did say it would take a few weeks to organise. We'll see what happens.

Send them round to my house when they are done.  Ill even throw in a cup of tea and a jammy dodger.

[odbob]

From my experiences and those of others, not just on this forum I might add, it seems that the industry has been, and presumably still is, hopelessly incapeable of doing the job properly, leaving a vast number of homes with inadequate insulation

[biff]

I would have to agree odbob.
                         Clive,,It would be a good idea to check if the apron was fitted to your house.I get the feeling that the folks involved would have been smart enough to know.If the apron is there,it might be even a pvc one but it will mean that you can fill the lot up with bonded beads and not worry about bringing in the damp.
                                           Biff

[clivejo]

Unfortunately, there is no one alive who remembers it.  I was about five at the time and dont remember much about it.  From the plumbing work I did a few months ago, it looks like the solid wall was capped with a layer of concrete.  The inside cavity wall looks to be on a plastic damp course, but I cant be sure.

[biff]

Hi Clivejo,
        Well if the plastic dpc steps up 6" or 9" onto the inside skin then thats the apron and if you have that you can fill away.The apron is designed to throw the water which travels down the back of the outside skin back out to the outside face,hence the weeps.(little plastic vents100mmhigh by 20mmwide) or just little holes.
                                                                                   Biff