Do i have celotex insulation?

oldskoo1

We just moved into an 8 year old house which apparently doesnt have cavity wall insulation. Previous owners had 2 companies come out to fill it, both said they would chip the bricks because of the mortar width.

I thought this was just standard disclaimer stuff, but i'm more surprised it even needs filling.

I was in the loft today, it's a 3 storey house with rooms in the roof. In the loft you can see the eaves on the outer walls and sloping down under the roof line and then when it meets the walls are PIR/Celotex boards slotted in the gap between the roof and the wall.

So i was wondering, as it is very unusual for a new house to not have cavity insulation, would a builder install these PIR boards in the cavity? We have the skirting off downstairs and i couldn't tell if the boards are in place as i assume they place it between the breeze-block and the brick?

Is there any way to tell without using a borescope?

It could just be a red herring, perhaps the previous owners had the loft insulation put it and the people doing it just slotted this PIR board stuff down the gaps in the roof, as it's not even secured in and it's not a snug fit either.

Also, i'm questioning why these companies are suggesting a cavity fill? If the PIR/Celotex are nailed to the breeze-block do they still leave a small gap for ventilation and could this be what they are suggesting be filled?

Thanks,

cyclonebri1

An 8 year old house would have had to meet the regs of the day, I don't think they have changed too much.

Filling the cavity is simply the cheapest way of going close to the requirements, would need thermal blocks/aerated or spot dabbed plasterboard to complete.

I have had several conversations with cavity wall installers recently.
We paid for this to be done and were never convinced it was done correctly, 25 year guarantee from a co that folded 3 years later.

So we got folks in, all offered to bore scope the wall before any commitment.
As regards the issue of chipping bricks, they will drill in the corner of 3 bricks, ie, where the gap twixt the 2 above sit on the row below.

They will chip them regardless of brick gap.:eek:;);)

budgetdiyer

If i remember correctly an 8 year old house would have cavity wall insulated when built.

As the previous poster stated all (reputable at least!) companies will check at the initial stage without charge!

oldskoo1

Thanks guys, think it's wise to get people out ourself.

Thinking about it, i'm not sure if the previous owners ever got to the borescope stage.

When they build it i assume they don't inject it, do they tend to use that rockwool or do some of them use those PIR/Celotex boards?

The odd thing is, quite a few houses on this estate have had injected insulation, all houses are newer than 10 years old; including my brothers house a couple of streets down, he had it done. So it makes me wonder if the builder used those foam boards and left a small ventilation gap. If not, all these houses must not have any insulation which seems crazy.

keystone

Most use Celotex or similar these days. Its put in before the second leaf is built.

Cheers

keystone

oldskoo1 wrote: »

If not, all these houses must not have any insulation which seems crazy.

Don't believe everything the envirostasi say. My house isn't cavity wall insulated and the walls aren't insulated internally either. Neither does it have five vertical feet of stuff (yes yes hyperbole) crammed into the roof and my house can breathe the way it was originally intended to do.

So I don't have a condensation problem and my energy usage is average for my type of house including the ones that have had the hell insulated out of them.

Cheers

oldskoo1

I agree I would prefer to allow it to breath but with energy costs rising cavity insulation has been a thought if we have none at all, it's a fairly big 5 bed.

If they used celotex would they leave a small gap for ventilation or are the celotex boards a full 50mm?

If not, that might explain these companies injecting poly into our cavities.

cyclonebri1

oldskoo1 wrote: »

Thanks guys, think it's wise to get people out ourself.

Thinking about it, i'm not sure if the previous owners ever got to the borescope stage.

When they build it i assume they don't inject it, do they tend to use that rockwool or do some of them use those PIR/Celotex boards?

The odd thing is, quite a few houses on this estate have had injected insulation, all houses are newer than 10 years old; including my brothers house a couple of streets down, he had it done. So it makes me wonder if the builder used those foam boards and left a small ventilation gap. If not, all these houses must not have any insulation which seems crazy.

That's the point I was getting at, cavity wall ins is the cheapest way to hit the rating require then and today, but it can be achieved in other ways, but for economic reasons it's unusual.

The advantage in your case is that you can add insulation without internal damage.;)