Cavity Wall Insulation

[dcawkwell]

A while ago I had british gas around to survey for loft and wall insulation.

They did the loft insulation but wouldn't do the cavity because the construction of the rear wall was different either solid wall or something.
Guy said something like there were bricks going across the walls.
He said they wouldn't do the insulation on the other 3 walls because this
could cause damp patches on the rear wall.

Last week 2 people turned up from another company uninvited did a survey and seem to be suggesting they can do the cavity wall insulation on the 3 walls.

I am now dubious if this is a good idea from what british gas said. As I don't want damp.

Can anyone offer advice on this?

 

[Robotmannick]

I have a rule that if anyone turns up uninvited then they're sent packing. I've never yet met a good tradesman who has to tout for business door-to-door.

I'm no expert on cavity wall insulation whatsoever but think about it from BG`s point of view...why would they refuse a money-making opportunity if there wasn't a good reason?

Nick

 

[JohnD]

how old is the house?

 

[dcawkwell]

how old is the house?

1925

 

[KenGMac]

dcawkwell, Hi.

Looks as if you like hundreds of thousands of others have been subjected to the infamous clod call from a so called insulation specialist, funded by a Government initiative and funded by everyone who pays their utility bills, that is the bottom line, that is why everyone's energy costs are rising.

I think this is what is termed the so called Green Tax?

What appears to have happened in your case is that B / Gas's so called approved Contractor has probably used a bore scope or similar to have a look into the cavity and seen that the so called brick ties are in fact bricks that completely bridge the cavity from outer skin of brick to the inner skin of brick.

This type of construction was used extensively, the brick across the cavity as a so called tie in the 1920s and 1930s

If that sort of cavity wall were to be filled with cavity wall insulation, presuming that the Survey by B / Gas was correct then yes you could expect that at some time in the immediate future your inner walls will be spotted with a series of very dam patches, because the across cavity brick ties will allow any dampness from the outer leaf to track across and get to the inner leaf.

What I find of interest here is that there are or have been hundreds, if not thousands of so called job Adverts for cavity and loft Insulation so called "Surveyors" but the kicker is that there is quote " NO EXPERIENCE NECESSARY"

Now what does this say about some aspects of this Important and necessary industry?

Hope this assists?

Ken

 

[JohnD]

1925? I would be very surprised if it had true cavity walls.

It might have rat-trap bond or something

I'm with Robot.

If you want another reputable opinion, ask your electricity supplier to have a look at the house. At least you can be fairly confident they won't go bust leaving a worthless guarantee.

 

[tony1851]

It might have rat-trap bond or something

For a house? Built in 1925??

 

[dcawkwell]

dcawkwell, Hi.

Looks as if you like hundreds of thousands of others have been subjected to the infamous clod call from a so called insulation specialist, funded by a Government initiative and funded by everyone who pays their utility bills, that is the bottom line, that is why everyone's energy costs are rising.

I think this is what is termed the so called Green Tax?

What appears to have happened in your case is that B / Gas's so called approved Contractor has probably used a bore scope or similar to have a look into the cavity and seen that the so called brick ties are in fact bricks that completely bridge the cavity from outer skin of brick to the inner skin of brick.

This type of construction was used extensively, the brick across the cavity as a so called tie in the 1920s and 1930s

If that sort of cavity wall were to be filled with cavity wall insulation, presuming that the Survey by B / Gas was correct then yes you could expect that at some time in the immediate future your inner walls will be spotted with a series of very dam patches, because the across cavity brick ties will allow any dampness from the outer leaf to track across and get to the inner leaf.

What I find of interest here is that there are or have been hundreds, if not thousands of so called job Adverts for cavity and loft Insulation so called "Surveyors" but the kicker is that there is quote " NO EXPERIENCE NECESSARY"

Now what does this say about some aspects of this Important and necessary industry?

Hope this assists?

Ken

I can believe there are cross bricks as there seem to be end bricks showing in the brick layout when viewed from the outside.
Looking at the other walls the brick arrange is standard long side brick ... all along the wall.

So is it ok to insulate the cavity on the 3 other walls as the other company wants to do?

 

[rjm2k]

I would stick with what BG said and since you can't do 3 of the walls its pointless doing just 1. The cowboy will take your money and run.

 

[KenGMac]

dcawkwell, Hi again.

I would go with what John D has posted, that being get another reputable energy supplier round to have a look.

If you do try to make sure that you are there to see what they are doing. What should happen is that the Surveyor bores some holes into the outer leaf, the rational behind this is that, the property may have been cavity wall insulated historically, important if the property has recently changed hands, as if a cursory inspection of the outer leaf will instantly show up the in filled injection holes. just one of the rules that apply in this so called industry?

The other reason is, to check that the cavity is clear with no build up of mortar, conventionally on the metal wall ties or in your case on at least one wall the through brick ties, that are acting as the ties.

What is somewhat shall we say, un-conventional in your property is that there is one wall with through brick wall ties, so what is happening within the other three walls? did anyone inform you what was going on in the other three walls?

Looks as if I got the dates about right? I think that at that time the through brick wall tie was if you excuse the following a particularly English practice, I have only seen three examples of through brick wall ties in Scotland?

This so called industry, starting with a knock on the door seriously worries me, in that, from what I have seen a swarm of youngsters, who are right off the doll queue descend or are shipped into an area where they simply knock on doors, asking about several thing.

One, is there cavity wall insulation?
Two how thick is the loft insulation?
Three how old id the C/Heating unit?

If all three above can be replaced then the door knocker gets paid, if not no payment, it is as ruthless as that, but the remuneration is fairly high.

After this a bunch of at times real Cowboys move in and the insulation process begins.

I have yet to hear of any insulation Company advising that roof ventilation should be maintained or indeed increased.

As for cavity wall insulation? I for one have seen a lot of historically installed cavity wall insulations that have failed seriously badly and the entire inner surface of a ground and fist floor property saturated to the extent of the wall paper falling off, not nice. Last week I saw a property where the Insulation had been installed about 5 / 7 Years ago where the external pointing to the brick was breaking down to an alarming extent.

 

[tony1851]

+1