Cavity wall insulation .......

[gasbanni]

I always wondered how come it didn't cause damp because it bridges the cavity ..............to prevent this remember the battens brick layers used to put in the cavity to stop mortar falling on the ties and giving a bridge for moisture to get across ? The batten prevented this very thing and they pulled it up as they worked ......

Father in law, a clerk of works told me he'd seen on lots of occasions water running down the inside face of the outside leaf........ so I wonderd why cavity wall indulation didn't cause problems .... ..it does !!


http://www.bbc.co.uk/news/uk-wales-42165358


http://dailym.ai/2k1t1KT

 

[KenGMac]

gasbanni, good evening.

The shall I call it, General principle of introducing insulation into the cavity is a very attractive concept, primarily a warmer home.

Down side is as we all know cavity bridging on an enormous scale, far greater than a mortar blockage in a cavity or even a half brick occasioning the bridging.

I have seen many, many dozens of such cases of cavity insulation occasioning horrendous damage both internally and externally.

If you have the time and more especially the inclination, you will find research that clearly states that Cavity Wall insulation is NOT advised in almost all areas of the UK??? the exposure to wind driven rain Etc, there are graphs and maps that indicate areas where such installation is simply not advised, and I am not typing about a property on top of Ben Nevis???

Several years ago there were many, many job adverts for so called "Cavity Wall Surveyors??" the outstanding part of the adverts made it abundantly clear that there were "No Previous Experience" was required???

There are several on-site checks that the cavity wall surveyor should check for by drilling into the cavity from the external these checks are supposed to include, the width of the cavity?, has the cavity been filled historically?, using a bore Scope the surveyor has to check for cavity blockages, but given the last phrase in the foregoing paragraph I for one do not think the Sheriffs won over the plethora of Cowboys.

Early versions of Cavity Fill, such as blown fiber were a complete disaster in places.

Historically I do well recall the use by bricklayers of Cavity boards, they worked, but is one was left in place the internal damage was nasty, but nowhere as bad as cavity fill.

Any remedies??

Removal and drying of the walls is fairly well known, but who pays??

Most / all such Installations were [so called] backed up by an insurance [of sorts]

Big trick is to find out who Underwrote the original Insurance Policy which covered the Installation, if you can locate the Underwriter then once they accept Liability they will pick up the tab for repair.

A complete can of worms??

Today's massive innovation will give years of future investigations as to the remedy to the original innovation??

Ken

 

[gasbanni]

I remember the problems with mortar bridges on the ties causing circular damp patches on the internal walls of some rather prestigeous s propetries !

Do you have any links to the reports you mention ?

There's companies now set up to remove cavity wall insulation and pumps designed to do the job, I can imagine it's a problematical job ensuring it's all being removed.

It depends on the insulation material used I suppose and short of examining all of the cavity with expensive cameras I can imagine it's a tricky process to ensure its all been removed.
If the insulation prevents the cavity drying out I suspect it could have exacerbated wall tie erosion .........Obviously depending on the type of ties used.

 

[magicmushroom666]

I've seen lots of new builds where they put cavity batts in between, surely that's just the same?

 

[Ian H]

 

[gasbanni]

No it isn't there's plastic shields you clip to the ties to stop water migrating across and you leave a slight gap.
There no gap with cavity wall, insulation it bridges the cavity .

I've seen lots of new builds where they put cavity batts in between, surely that's just the same?

 

[gasbanni]

View attachment 131912

And the point ?

 

[Ian H]

And the point ?

Are you not talking about cavity insulation and damp? I saw that when I filled my car up, seems to claim it's somehow waterproof.

 

[KenGMac]

gasbanni / Ian H, good evening again.

OK a complete can of worms

Ian, yes Cavity batts are installed, but the insulation material is held firmly against the cavity face of the internal leaf, the batt does not fill the cavity, there is an air gap which allows any rain water driven through the external leaf, because of the air gap between the external leaf and the insulation the driven water does not saturate the insulation, and in turn cannot get to the internal leaf [or so it is hoped ]

gasbanni, if you have a look on line, there are some real diamonds out there such as

Post Installation Performance of Cavity Wall & External Wall Insulation

www.cewales.org.uk/.../Post_Installation_Performance_of_Cavity_Wall__External_

The above is moderately comprehensive in that it touches on some very important areas such as exposure to wind, a major feature in initial assessment as to whether the property is indeed suitable for retro-fill cavity insulation.
In effect the above gives areas for further web searches, at one time I was holding several BRE digests Etc. on this subject but that was some time ago.

As for assistance in removal of this defective material??

Have a look at this link, but I have no idea as to how good or otherwise it is?

https://www.whatdotheyknow.com/request/informationreport_of_bre_on_cavi

In general terms when the Insulation was installed there was a sort of Insurance backed guarantee If someone wants the Insulation removed that Policy has to be located and a claim made.

Over the years these policies have changed hands, trying to recall who the original Insurer was can be a problem?

These Insurance Policies sometimes lasted for as little as ten years, others 25 Years, just keep digging to find it?

There are several so called "Loss Assessors" who can assist, but beware these guys will want to be paid and then it gets really complicated.

Ken.

 

[KenGMac]

gasbanni, hi again.

Did some more digging as to this subject and found the following.

http://www.publiclawtoday.co.uk/hou...-over-poorly-installed-cavity-wall-insulation

The above makes for interesting reading.

BUT??

The following link possible could assist in locating the insurance policy that was taken out to guarantee your Retro - Filled Cavity Wall insulation, remember you will need to locate this Policy to intimate an Insurance Claim to have the Insulation removed and your home made habitable again???

OK. I have not tried this site [I live in a Georgian conversion constructed in 1823 with solid stone walls] But this site may be worth a look ???

www.wallcavityclaims.co.uk/ciga/get-a-copy-of-your-ciga-certificate/

Ken.

 

[geraldthehamster]

No it isn't there's plastic shields you clip to the ties to stop water migrating across and you leave a slight gap.

You're confusing cavity batts with solid insulation boards. The latter are correctly installed with clips holding them to the inner skin, and a gap; whereas cavity batts are installed full fill.

 

[gasbanni]

You're confusing cavity batts with solid insulation boards. The latter are correctly installed with clips holding them to the inner skin, and a gap; whereas cavity batts are installed full fill.

No I'm not my description might be a bit out or my typing I'm not confusing the two !!

 

[geraldthehamster]

No I'm not my description might be a bit out or my typing I'm not confusing the two !!

Yes, I'm sorry, it was KenGMac who referred specifically to cavity batts not being full fill.

 

[KenGMac]

Ooops?

Sorry everyone. bats Etc.

Well what do you want? Cricket is not our national sport, come to think of it do we have a national sport? draw a veil over Soccer at national level, hopeful for this up coming Rugby season??? [nobody hold their breath]

As for my preferred sport, I will continue to hold my breath and gently squeeze the trigger?

Seriously sorry for confusion caused.

Ken