Cavity insulation

[nickk]

We are going to renew our heating installation in the coming weeks,our oil boiler is 34+ years old,so done well,oil.
The type we choose is partially guided by the government RHI,however one condition is compulsory cavity insulation,I’ve only heard bad reports of this and am sure in principle it can work effectively,is there a tried and trusted method?
The house is two storey,ground floor walls are 20” which is stone/cavity/block,iirc blocks are solid,built around 1980-1984.
Upper floor walls are thinner as there’s no stone outer.
The negativity I’ve heard is always damp issues.

 

[Kayos]

Is it definitely specified or is it recommended to meet the U values?

Internal wall insulation is good these days

 

[brightspark]

Is it definitely specified or is it recommended to meet the U values?

Internal wall insulation is good these days

what type ?

 

[Kayos]

what type ?

We used to use Knauf, about 1.5" thick on any external walls, then board and skim over it

 

[nickk]

Is it definitely specified or is it recommended to meet the U values?

Internal wall insulation is good these days

It’s a requirement to get the RHI ,which is a considerable sum.

 

[Kayos]

It’s a requirement to get the RHI ,which is a considerable sum.

That doesn't seem like a cavity fill?

But is cavity fill specified or is the requirement to bring the insulation to a certain standard?

I only deal with commercial rhi so the rules may be different but my projects only have to bring the heat loss to a certain level, they do not specify how that has to be achieved

 

[addjunkie]

I thought you just had to have a certain letter or better on that pointless survey They do.

 

[gaz1]

The type we choose is partially guided by the government RHI, however one condition is compulsory cavity insulation, I’ve only heard bad reports of this and am sure in principle it can work effectively,is there a tried and trusted method?
The house is two storey,ground floor walls are 20” which is stone/cavity/block,iirc blocks are solid,built around 1980-1984.

dont ever fit internal stuff worst thing going

i presume that you have to have r rating home and there is different things you can do

cheap use blow in insulation yeah right biggest con going see so many homes having it removed

other 2 options internal vs external insulation you pick your punishment

 

[brightspark]

my roofs well insulated but the walls arent and wont get done by me because of all the bother people are having with it. if it had been tried and tested for 30 years id consider it

 

[gaz1]

i can throw every fault against insulation in old homes it has its issues with doing them

internal wall insulation is depth vs air lose the air and you lose the barrier between the outer and inner walls
its a big con to be told that internal insulation is a good thing there is no product on the market that can give a good value over years vs damage to the property ( water damage )

new builds are thicker on the walls with internal 2" insulation

internal insulation is a fire hazard and poisonous behind a 1/2 hr plasterboard

external insulation has its issues and can cause brick or stone damage

so its either take wall down move the wall forward fit internal insulation inside of it

 

[Morrisman]

When my parents bought their first house, 1970, four bedroom detached, it had no insulation whatsoever, and just a single fireplace in the front room for heating.
First time they decorated they stuck 1/16” polystyrene to the external walls then wallpapered over that. All the upstairs ceilings were then covered in 1’ square polystyrene tiles, 1/2” thick.
They even put insulation in the loft, 3” thick polystyrene blocks.
And dad made his own double glazing on all the windows, using perspex sheeting and wood beading to hold it in place.

I can’t imagine such simple, yet futuristic, improvements are allowed today.

 

[JMS1972]

When my parents bought their first house, 1970, four bedroom detached, it had no insulation whatsoever, and just a single fireplace in the front room for heating.
First time they decorated they stuck 1/16” polystyrene to the external walls then wallpapered over that. All the upstairs ceilings were then covered in 1’ square polystyrene tiles, 1/2” thick.
They even put insulation in the loft, 3” thick polystyrene blocks.
And dad made his own double glazing on all the windows, using perspex sheeting and wood beading to hold it in place.

I can’t imagine such simple, yet futuristic, improvements are allowed today.

On account of polystyrene being really flammable? Or did they have fireproof wall paper?

Plus it gives off horrendous fumes when burning

Death trap springs to mind.....

 

[gaz1]

When my parents bought their first house, 1970, four bedroom detached, it had no insulation whatsoever, and just a single fireplace in the front room for heating.
First time they decorated they stuck 1/16” polystyrene to the external walls then wallpapered over that. All the upstairs ceilings were then covered in 1’ square polystyrene tiles, 1/2” thick.

I can’t imagine such simple, yet futuristic, improvements are allowed today.

oh but they are

as a reminder of composite insulation this is what your dealing with

 

[Morrisman]

On account of polystyrene being really flammable? Or did they have fireproof wall paper?

Plus it gives off horrendous fumes when burning

Death trap springs to mind.....

Twas the done thing then, commercially available products, for both wall and ceiling.

 

[rtcosic]

I had cavity insulation fitted to our previous house. It was the blown-in coated polystyrene (?) bead type.

After a few years, the most exposed end wall started to show black mould on the outside - a very common feature of coastal Pembrokeshire, so I thought little of it.

A few years later one corner of the French windows started to show damp on the plaster at skirting level.

After a few more years of trying and failing to seal 'leaks', I eventually decided it was water running down the inside face of the external brick wall. Presumably, there was a very slight fall in the DPC level and all the free water collected in this corner. Or some other reason we can endlessly speculate about.

As the house was built in 1989 it did not have any of the modern cavity closures with drains above lintels or drains above the DPC which may have helped avoid this.

I would not use cavity insulation again.

 

[nickk]

But is cavity fill specified or is the requirement to bring the insulation to a certain standard?

I only deal with commercial rhi so the rules may be different but my projects only have to bring the heat loss to a certain level, they do not specify how that has to be achieved

Require to a certain standard,put off insulating internally because of the upheaval within a family.

 

[Kayos]

Don't dismiss cavity wall insulation just because of the horror stories

There is a huge difference between some chancers in an old transit Luton with an air blower and a bag of fluff, and a pro outfit who use different insulation and carry out proper surveys

 

[brightspark]

ive knocked or cored holes through walls and found the insulation in the cavity was damp thats why they make brick ties with the twist in the middle and face them down over

 

[gaz1]

Don't dismiss cavity wall insulation just because of the horror stories

There is a huge difference between some chancers in an old transit Luton with an air blower and a bag of fluff, and a pro outfit who use different insulation and carry out proper surveys

dream on its a con job

cavitys are there for a special reason to keep water out from internal walls remove it at your own costs

old houses have stood the test of time with them whilst modern need to be rebuilt in 50 years

ive knocked or cored holes through walls and found the insulation in the cavity was damp thats why they make brick ties with the twist in the middle and face them down over

same issues here and had to do it in many homes for new plumbing and other stuff

 

[Kayos]

dream on its a con job

cavitys are there for a special reason to keep water out from internal walls remove it at your own costs

old houses have stood the test of time with them whilst modern need to be rebuilt in 50 years

same issues here and had to do it in many homes for new plumbing and other stuff

Summarises the attitude of this forum

All tradesmen are cowboys and will rip you off

What a load of nonsense

Im surprised you haven't linked a video yet