Eps vs Kingspan

[Brickie]

Hi all,

Has anyone done (or knows of) a cost/performance comparison of blown in beads against Rigid board cavity insulation?

Been asked to price a job with a wall make up if 100mm aerated block/100mm cavity with 90mm Kingspan or similar/100mm face brick. 

For many reasons it’s gping to be an absolute pain to use this system (not least a lot of 327mm piers) so I’m trying to talk the client round. 

Tia,

Brickie

[Russell griffiths]

Could you say that you can’t guarantee the quality of the insulation install with so many cuts,

lots of chances to have gaps and poorly fitted insulation, any gaps will effect the insulation value

 

so really even if kingsman is better, eps beads will be better than gappy kingspan 

 

as an ex bricky I would have thought the time saved cutting all the kingspan would pay for the eps...?.?

[Mr Punter]

I looked at a similar comparison before but you will need a 150mm cavity to get similar u values, so wider footing and smaller floor area.  We used Celotex full fill boards - they are currently suspended from sale.  The Kingspan looks a pain to work with.  How you are supposed to maintain a 10mm residual cavity and tape all the boards is beyond me.  Probably never happens on site.

[Brickie]

Thanks for your replies. 

I agree that the ‘real world’ installation of this system is never going to achieve the u-value it should on paper & the beads would give a more accurate figure of what you would actually get. 

My problem is that the client has no technical background & isn’t confident to challenge the architect for a revision. 

[Declan52]

I used the Kingspan boards for mine. They had small fins on them to maintain a narrow gap at the face side. They are very dense so not easily cut straight. Build the cavity 10mm wider as the fins will push the soft side out of plumb.

Cost wise when you are doing it the boards will be more expensive to buy plus more costly time wise to lay and then you have how many gaps you will leave. No way would I have let anyone else do mine as they just wouldn't have been able to take their time plus build enough blocks to make a wage. It would be the wider cavity and beads for me. 

[Brickie]

No scope for wider cavity as the job’s up to block & beam already. 

I’ll just have to put such an astronomical surcharge in the price for  fitting boards that the economic argument might prevail :))

[Declan52]

Def put enough on to cover  yourself.

How wide are the founds?? Could you get the cavity to 125mm or maybe a slight bit more.

[Brickie]

I’m stuck with what’s there as the beam & block is already in. 

Only going to be a bloody pub as well!!

[MikeGrahamT21]

Correct me if im wrong, but with block > Cavity > Brick, and 100mm cavity, you can only go a max of 50mm with standard PIR boards (for building control). There are products such as Xtratherm CT-PIR which is designed to full fill, but its insanely expensive, and is a very specific product for fully filling a cavity.