Slight compression of insulation with loft stilts normal?

_ZeeK_

Hi folks - Looking to install some tongue and groove boards in the attic for storage. House is a new build so is well insulated.

Bought a couple of packs of loft stilts in B&Q to avoid compressing the fibreglass insulation. However, when I went to test them by putting a couple in place and a board on top, it's compressing the insulation ever so slightly. Stilts are 270mm but have since checked depth of insulation and it is 300mm in parts. Foolishly assumed that because they were the only variety of stilt available in the store, they would do the job!

Would the 3cm compression have much of an impact? Have done shopping around online and there seems to be 'XL' stilts - 300mm - but they lack clips to wrap around the trusses so will be more awkward to install. Worth getting these in this case or good to fire ahead with what I have?

Lumen

I wouldn't worry about it

https://www.energyvanguard.com/blog/compressed-fiberglass-insulation-really-so-bad/

C. Eastwood

https://www.boards.ie/discussion/2058226900/slight-compression-of-insulation-with-loft-stilts-normal

_ZeeK

it will make no difference to the heat transfer in our mild Irish climate.

The timber of the deck will also slow down the heat transfer.

The present U value of your ceiling is approx 0.14 Watts/ M2 /difference in DegreeC/hr.

New U Value is 0.16 watts / m2 / etc

Assume 20 m2 of flooring over 270 mm insulation

Assume 20 deg C in the house and present outside (attic) temp 12 deg C .

Therefore approx heat loss is 0.16 watts x 20 m2 x (20 deg c - 12 deg c)/ hr

= 0.16 x 20 x 8 / hr = 25.6 watts heat loss per hour.

You are super insulated.

A 12 mm plasterboard ceiling with no insulation has a U value of approx 2.1w/m2/degreeC/hr