Insulation regs

Ginger83

On a new extension, facing northwest, does a 100mm pumped cavity and a 25mm insulated board on exterior walls pass building regs?

Gumbo

Ginger83 wrote: »

On a new extension, facing northwest, does a 100mm pumped cavity and a 25mm insulated board on exterior walls pass building regs?

http://www.housing.gov.ie/sites/default/files/publications/files/technical_guidance_document_l-_dwellings_2017.pdf

Have a look at section 0.1.3 (Existing Dwellings)
It will guide you and point you to specific other sections and values.

Ginger83

kceire wrote: »

http://www.housing.gov.ie/sites/default/files/publications/files/technical_guidance_document_l-_dwellings_2017.pdf

Have a look at section 0.1.3 (Existing Dwellings)
It will guide you and point you to specific other sections and values.

Thanks, it seems to be a very grey area, nothing definite in regs.

mickdw

Ginger83 wrote: »

Thanks, it seems to be a very grey area, nothing definite in regs.

Im pretty sure the minimum wall u vlaue for extensions is nailed down in part L.

listermint

Does it matter if it's a new extension you should exceed any minimum.

For me that spec is poor

Gumbo

Ginger83 wrote: »

Thanks, it seems to be a very grey area, nothing definite in regs.

Definite figures to achieve are in that document. Someone needs to do the u value calculation to ensure it complies.

Ginger83

listermint wrote: »

Does it matter if it's a new extension you should exceed any minimum.

For me that spec is poor

It could well be poor but does it meet regulations.

What would you have used?

Gumbo

Ginger83 wrote: »

It could well be poor but does it meet regulations.

What would you have used?

I’d rather keep the insulation all in one place. I don’t like splitting it up. Someone also also has to do a dew point calculation on the section.

In general 125mm is a good build up, even the 100mm full full is good in my
Book.

BryanF

kceire wrote: »

I’d rather keep the insulation all in one place. I don’t like splitting it up. Someone also also has to do a dew point calculation on the section.

In general 125mm is a good build up, even the 100mm full full is good in my
Book.

Just to be clear you are talking about 100 rigid PIR in the cavity and not pumped beads

The equivalent Polystrene bead would be more than 150mm

Ginger83

BryanF wrote: »

Just to be clear you are talking about 100 rigid PIR in the cavity and not pumped beads

The equivalent Polystrene bead would be more than 150mm

Hi i mean the cavity is pumped with beads and the slab on inside of block has 25mm of insulation on it.

dathi

mickdw wrote: »

Im pretty sure the minimum wall u vlaue for extensions is nailed down in part L.

slip of the tongue there mick it sets out the maximum u values allowed

mickdw

dathi wrote: »

slip of the tongue there mick it sets out the maximum u values allowed

Yep fair enough. I should have said it sets out the minimum standards.