Cavity Wall Insulation

Cavity Insulation - Don't Do It!


Gerry Miller (CEO) CIGA was given a roasting on BBC radio 4 yesterday.  This is a MUST listen interview:

BBC Radio 4 - Roasting the CEO of CIGA

(Fast forward to 17.30 on the timeline)

Our wonderful Government is trying to flog you insulation.  It doesn't work.

If a cavity wall was meant to have insulation in it, it would be there.  The fact that older cavity walled buildings do NOT have insulation, is because they were designed that way.  The cavity allowed water to penetrate the outer leaf, run down inside, and flow away - leaving the inner leaf dry.  Put insulation into that building, and it will get wet.  It will rot any cavity ties into the bargain - costing you a serious amount of money.

We are trying to persuade the Government they are wrong.  Try telling ANY of the idiots in Westminster that their hare brained schemes are wrong, and they run screaming for the hills.

The Government is wrong.

The Green Deal is dead - their biggest scam, flop, mad scheme, money making invention for their cosy mates - call it what you will, but it's dead.  It never worked, and it was never going to.

Insulating old houses is a technical and complex game.  The idiots who come knocking on your door trying to sell you free insulation are just that - moronic, brain dead idiots - paid peanuts by sales managers who have huge sales targets to meet, and who are paid Government money to do so - OUR money.

If you want to warm your house up, and it's old - there's a bunch of things you can do that won't damage the house, or give your children asthma from increased allergens, mould, fungus etc from ill conceived insulation attempts:

  • Manage humidity - keep the air dry - extract moisture.
  • Fit roman blinds or secondary glazing
  • Insulate your loft by all means - but VENTILATE IT!
  • Keep heating running all the time - but very low - aim to keep the house at 15 degrees C 
  • Think humidity - all the time - humid air is what makes it feel cold
  • Your walls are NOT losing heat at the rate the Government says they are
  • Check your drains - make sure all your drains are in top condition - 75% of old houses have leaky drains causing damp.
  • Make sure ground levels are below internal floor levels.

If you are still cold after all this - call us and we'll do our best to help.



Cavity Wall Insulation - the sleeping horror for thousands of older homes

I recently received an email from a professional colleague in response to discussion about the increasing incidence of Cavity Wall insulation getting sopping wet.  He says..:


"I have dealt with a good number of cases where cavity wall insulation is failing across south-west Wales and in a number of instances where CIGA have as a result of my reports agreed and instigated its removal. As most of the west coast of Britain was described by BRE as being very severely exposed to driving wind and rain (in their publication 'Thermal Insulation Avoiding the Risks' and other similar guidance, decades ago) most of the post 1910 building stock, is patently unsuited to its installation;unless the external cavity wall is already over clad with an impermeable cladding such as slate, tile hanging or timber boarding, the construction detailing is perfect and the micro-climate, sheltered. 

The installers should check carefully, but this does not happen in the frenzy to draw down payments and those managing larger schemes are budget driven.  

I have personally been amazed, that this scam has been encouraged and perpetuated by politicians of all persuasions, built environment professionals, environmentalists and public and private organisations that should know much better. The general public have been conned and their properties increasingly damaged. The exceptionally severe recent winters are compounding problems, yet many householders are reluctant to publicise, as they are either embarrassed or realise that their home is damaged and potentially any asset value is diminished.  

Issues afflict properties of all periods  but in my working location it is especially prevalent on the south and west  facing elevations. The early 1920's stock with black-lime ash mortar bed joints, sulphate decayed cement render overlying brick  cavity walling with failing wall ties and poorly built cavities are particularly vulnerable. Companies have been masquerading and abusing the BBA Certification process. They fail to check that the cavities are clean, sufficiently sheltered and that they are not bridged by chimney breasts; or have functional cavity trays and damp courses installed around openings. The number of times I have rung water from  blown mineral fibre insulation that is as wet as a dish-cloth are numerous.   The irony is that the installers of the system now advertise that they also remove cavity wall insulation. Where I have had this undertaken by them, they generally leave insulation within localised pockets  and have to return or a general builder is then engaged separately to do the work properly. The installers use of a powerful 22mm diameter impact drill (used without a pilot hole) in order to bore the holes required to blow in or suck out insulation often causes further structural damage. This compounds where wall ties have already been replaced and thin stainless remedial ties are fitted. In one property where a clay common brick with slag core was in use, the removal of insulation resulted in 26 broken brick batts being left within the walls that were split and appeared almost as 'Queen Closers'. Ultimately, numerous cleaning pockets end up having to be cut out, the cavities cleaned properly, bricks reinstated, letters sent to LABC to explain why, potentially thermal insulation is being reduced and the external walls re-rendered, and internal plaster and decoration replaced.  

It is time that there was a real debate about this topic as the EWI response is also littered with failure issues.  

We are potentially building problems that are stacking up like those of the 1980's Housing Defects Act.

Let's have a real debate on this...."


The writer is a very well respected Chartered Surveyor in the Welsh Valleys..

A little case history

This was a house we looked at which has cavity walls, with insulation - beads - which were sopping wet. We used the thermal imaging camera to find a cold area at the base of the wall - seen here as a darker region because it was damp, and evaporating moisture.  You can see green algae growing on the wall where it is cold.  The brighter section above has little or no insulation - this was a typical incompetent job which did nothing for the house involved.

Damp and Condensation
Check out the Government insulation schemes

Listen to the salesman.

Does he check your walls carefully for rubble?

Does he tell you the cavity is old, and unsuitable?

Does he talk about condensation?

No... he will tell you it's free, your home will be nice and warm, the Nice Government is giving you something for nothing...  and he will do his utmost to get you to agree to it there and then .. pressure sales.

Pink Pigs have more chance of flying than the salesman is honest, or knows anything about what problems he is about to unleash on your house.  But Go Ahead - check out their claims, and let us know your experiences - we like to hear the case histories of these scams, whether Government sponsored or not.  

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