cavity wall insulation
 

Hi,

Someone knocked on the door offering cavity wall insulation for £140.

I'm not sure whether the house (built mid-70s) has cavity wall
insulation or not; how can I tell?

If I do need it, is £140 a good price and are some companies better to
use than others?

I understand they inject something into the cavity but what do they
use? Is it like that awful expanding foam that you can't clean off?
What stops it rising up the wall and coming out of the top or through
air bricks etc?

We have a meter box cut in the side of the wall. Is there a danger
that the meter box will be flooded with foam?

Also the builders for some unknown reason decided to put the soil pipe
and rising main in the cavity behind the bathroom wall. I don't know
if I am worrying unnecessarily but if we ever needed to access the
soil pipe or main, would it be possible if they were caked in foam?

Thanks in advance.

cavity wall insulation
 

On Mon, 14 Apr 2008 17:39:33 GMT someone who may be Fred
wrote this:-

I'm not sure whether the house (built mid-70s) has cavity wall
insulation or not; how can I tell?

They should check this first.

If I do need it, is £140 a good price and are some companies better to
use than others?

The first thing to check is whether you can get it free or cheaply
http://www.energysavingtrust.org.uk/what_can_i_do_today/energy_saving_grants_and_offers
is a good starting point to check on this.

Whether £140 is a good deal or not partly depends on the number of
exterior walls your house has and its height.

I understand they inject something into the cavity but what do they
use? Is it like that awful expanding foam that you can't clean off?

No. They usually use small cut fibres which are blown in.

What stops it rising up the wall and coming out of the top

Gravity. A little will probably escape from the top, but can be put
back in for neatness.

or through air bricks etc?

They should check that all openings are sleeved before starting.

We have a meter box cut in the side of the wall. Is there a danger
that the meter box will be flooded with foam?

None at all if it is installed properly. Does it have gaping holes
in the back?

Also the builders for some unknown reason decided to put the soil pipe
and rising main in the cavity behind the bathroom wall. I don't know
if I am worrying unnecessarily but if we ever needed to access the
soil pipe or main, would it be possible if they were caked in foam?

The fibres can be moved to access things, though neither of those
things should be in the cavity wall.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

cavity wall insulation
 

On Apr 14, 6:52*pm, David Hansen
wrote:
On Mon, 14 Apr 2008 17:39:33 GMT someone who may be Fred
wrote this:-

I'm not sure whether the house (built mid-70s) has cavity wall
insulation or not; how can I tell?

They should check this first.

If I do need it, is £140 a good price and are some companies better to
use than others?

The first thing to check is whether you can get it free or cheaply
http://www.energysavingtrust.org.uk/what_can_i_do_today/energy_saving...
is a good starting point to check on this.

Whether £140 is a good deal or not partly depends on the number of
exterior walls your house has and its height.

I understand they inject something into the cavity but what do they
use? Is it like that awful expanding foam that you can't clean off?

No. They usually use small cut fibres which are blown in.

What stops it rising up the wall and coming out of the top

Gravity. A little will probably escape from the top, but can be put
back in for neatness.

or through air bricks etc?

They should check that all openings are sleeved before starting.

We have a meter box cut in the side of the wall. Is there a danger
that the meter box will be flooded with foam?

None at all if it is installed properly. Does it have gaping holes
in the back?

Also the builders for some unknown reason decided to put the soil pipe
and rising main in the cavity behind the bathroom wall. I don't know
if I am worrying unnecessarily but if we ever needed to access the
soil pipe or main, would it be possible if they were caked in foam?

The fibres can be moved to access things, though neither of those
things should be in the cavity wall.

--
* David Hansen, Edinburgh
*I will *always* explain revoked encryption keys, unless RIP prevents me
*http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

I am worried the grant scheme attracts companies out for a quick buck,
as was the case in the 70s/80s with loft insulation.
CWI is an hard to detect product for the householder is there a agency
too oversee the work and assess the performance of participating
companies?
AP

cavity wall insulation
 

Fred wrote:
Hi,

Someone knocked on the door offering cavity wall insulation for £140.

I'm not sure whether the house (built mid-70s) has cavity wall
insulation or not; how can I tell?

If I do need it, is £140 a good price and are some companies better to
use than others?

I understand they inject something into the cavity but what do they
use? Is it like that awful expanding foam that you can't clean off?
What stops it rising up the wall and coming out of the top or through
air bricks etc?

We have a meter box cut in the side of the wall. Is there a danger
that the meter box will be flooded with foam?

Also the builders for some unknown reason decided to put the soil pipe
and rising main in the cavity behind the bathroom wall. I don't know
if I am worrying unnecessarily but if we ever needed to access the
soil pipe or main, would it be possible if they were caked in foam?

Thanks in advance.

They don't use foam anymore, it's dry fibreglass, treated with silicone to
prevent water tracking across.
The fibreglass is pelletised (into small balls) and blown in with compressed
air...sometimes rockwool is used but the method is almost identical.
It only rises up about 12 inches, but will fall down (via gravity) about 4
feet, and across about 2, once installed, it never moves again until you
remove it manually

cavity wall insulation
 

Paul Matthews wrote:
David Hansen wrote:

On Mon, 14 Apr 2008 17:39:33 GMT someone who may be Fred
wrote this:-

I'm not sure whether the house (built mid-70s) has cavity wall
insulation or not; how can I tell?
They should check this first.

I think his concern is the door knockers were the insulation equivalent of an
offer to tarmac a drive, and that they may drill a few holes, faff with a bit
of gear and fill the holes having done nothing in reality.

Of course they were. No reputable company knocks on doors like that to
drum up business. (Yards from where I live is a no-doorstep-selling zone
- the need for these emphasises the nature of most doorstep sellers.)

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

cavity wall insulation
 

On Tue, 15 Apr 2008 19:32:18 GMT, Fred
wrote:

On Tue, 15 Apr 2008 07:19:28 +0100, Paul Matthews
wrote:

I think his concern is the door knockers were the insulation equivalent of an
offer to tarmac a drive, and that they may drill a few holes, faff with a bit
of gear and fill the holes having done nothing in reality.

Exactly so. I cannot see inside the walls so I don't know if I've got
it already and if I have it done, how can I tell that they have done
it properly and completely?

The company was KHI. I only know this from their ID badges; I have had
no other documentation from them. This worried me; I was expecting a
card or a brochure or something. Google says they are based in
Nottingham. I have found one good review online and one bad one.

A chap called today and drilled just one hole. He did not have
anything as fancy as a camera; he had one of those "claw" things that
you use to pick up things you drop behind the washing machine. He said
he could not find anything inside. However, I was suspicious of his
choice of hole. He had the whole side of the house to drill but
drilled above the air brick behind the boiler. Am I being paranoid or
ignorant here or is it that he thought there might not be any near a
vent?

I will have to have to see if I can put something inside the (still
open) hole and see what I can find. Certainly nothing poured out but I
did think I saw one or two microscopic white "feathers" fall out.

I will see that my electricity company offers a similar scheme albeit
for £20 more. Perhaps I should use them instead; at least I know who
they are, though I expect they contract out the insulation work
anyway.

Thanks.

You may find your 'electricity company' sub contracts to 'KHI', they
certainly don't do the work themselves. Being 70 yrs plus I had the
cavity walls in my home insulated for 'free' through my 'energy
supplier'. It was KHI who did the job (I live in Nottingham).

As far as I could tell the work they did was fine and was followed up
some days later by an Inspector to view what was done and to ask
whether I was satisfied with the work and the conduct of those doing
it. I was.