Is retrofit cavity wall insulation a good idea?

Is cavity wall insulation a good idea, a question im often asked. Well, provided you ensure the cavity is clean, you don't have any pre-existing problems with damp, you're not located near the coast, you're built upon sound free draining ground, you maintain your property free from leaks and defects and the insulation is installed properly you have much less chance of problems occurring with full-fill retrofit cavity wall insulation.
This short video however demonstrates exactly what happens to the insulation in an escape of water event. An escape of water event can cause significant damage to an insulated property if undiscovered. Sometimes the damage isn't always obvious and materials hidden within the cavities of construction can also be affected which may hinder the ability to dry and restore effectively if not accurately examined.
Dryfix, Yorkshires Leading Damp & Timber Specialists.

[@benlea19]

Interestingly most people don't have this problem with cavity wall insulation. It can happen but I'd be interested in 10 randomly selected houses being chosen with retrofit cavity wall insulation to see how many were like this

[@chrisl.9750]

same here, we got this and it works a charm, despite the house being old. most of these issues are down to poor workmanship and/or soaked ground under the property, making it's way the walls.

[@CCCP16]

Cavity-walls that are already built up can NOT have cavity-wall insulation added. Cavity-wall insulation can ONLY be installed from the very start of construction of the cavity-wall. Cavity-walls must NOT be bridged with insulation(insulation touching the outer walls inside the cavity-wall), or else moisture will transmit from the damp outer wall, through the touching bridging insulation, and into the inner wall; making the inner wall damp inside the property. If cavity-wall insulation is to be used from the very start of construction, there must be a large air space gap in-between the face of the cavity-wall insulation batt(panel) and the outer wall inside the cavity-wall; this includes an air space gap in-between the face of the cavity-wall insulation batt(panel) and the cavity-wall tie drip-point(which must point downwards in the centre of the cavity). Cavity-wall insulation batts(panels) must touch ONLY the inner wall inside the cavity-wall of course. Ask City & Guilds N.V.Q. BRICKWORK teachers in person for PROOF of this.

[@adriantyler9086]

Wanted to add cavity wall insulation to my 60s flat, but bridging the air gap seems frought with the danger of damp issues. Is there a safe way to do it?

[@CCCP16]

Can NOT be done

[@CCCP16]

Cavity-walls that are already built up can NOT have cavity-wall insulation added. Cavity-wall insulation can ONLY be installed from the very start of construction of the cavity-wall. Cavity-walls must NOT be bridged with insulation(insulation touching the outer walls inside the cavity-wall), or else moisture will transmit from the damp outer wall, through the touching bridging insulation, and into the inner wall; making the inner wall damp inside the property. If cavity-wall insulation is to be used from the very start of construction, there must be a large air space gap in-between the face of the cavity-wall insulation batts(panels) and the outer wall inside the cavity-wall; this includes an air space gap in-between the face of the cavity-wall insulation batts(panels) and the cavity-wall tie drip-point(which must point downwards in the centre of the cavity). Cavity-wall insulation batts must touch ONLY the inner wall inside the cavity-wall of course. Ask City & Guilds N.V.Q. BRICKWORK teachers in person for PROOF of this.

[@p.maesthetics7154]

How about no cavity insulation and maybe just some wrap

[@thrandumbguy]

In ireland we use full fill cavity insulation we are years ahead of the UK with building regulations

[@pauldavies7251]

And u think fully filling the cavity is a good thing!!

[@thrandumbguy]

@@pauldavies7251 belive me I used to think the same as you but its just old technology

[@pauldavies7251]

@@thrandumbguy I don't understand what u mean! Unless it's a passive house stopping air circulation is a ridiculous thing 2 do

[@thrandumbguy]

@@pauldavies7251 not inside the cavity. In ireland we are trying to build a house airtight and it costs about 10p a day to heat a 4 bedroom house.

[@kf5541]

@@thrandumbguy an airtight house, have you ever heard of relative humidity?

[@thrandumbguy]

That's why we don't use it in ireland