perimeter insulation strips

atlonglast

Floor insulation going in soon. We have got the perimeter insulation strips which are 150 mm high. Between the insulation and the screed the floor is going to be 160mm high. Can we screed completely over the perimeter strips by 10mm or is there still going to be cold bridging? Rang the technical dept. of the insulation but want to see if there's any other suggestions.

L driver

use 25/35mm rigid insulation cut into strips to suit floor height. WHY 160mm of screed?? add 70-80mm more floor insulation imo.

blast06

I thought to meet latest building regulations you needed 125mm of insulation under the screed ? Or perhaps your planning grant pre-dates this year ?

Outkast_IRE

blast06 wrote: »

I thought to meet latest building regulations you needed 125mm of insulation under the screed ? Or perhaps your planning grant pre-dates this year ?

I dont think you have to have 125mm , you can purchase a insulation with a lower u value and less width and achieve the same thing as far as i know. May be more expensive though.

shane6977

Why not just let the floor insulation butt tight to the perimeter walls, sit the perimeter insulation strips on top and trim down to suit the finished slab level?

sydthebeat

blast06 wrote: »

I thought to meet latest building regulations you needed 125mm of insulation under the screed ? Or perhaps your planning grant pre-dates this year ?

you cannot look at individual elements any more to discover if you comply with regulations or not.
the full construction must be assessed holistically.
125mm might suffice for some and not for others.

L driver

p/a ratio. but try to isolate the screed as much as possible from all walls, internal and external, rsjs etc etc with insulation strips.

atlonglast

I meant that the total of the insulation and the screed is 160mm. Regarding putting the strips on top of the floor insulation that's what the technical dept. had suggested to me!

manufan16

I done as L driver suggested
I bought sheets of 25mm insulation and cut strips approx 255mm-280mm in size, that covered 200mm insulation and 55-75mm of screed and a little bit left to trim off after the screed had cured.

You would probably get about 16+ linear meters of insulation out of one sheet

atlonglast

I rang the technical dept. again and they reckon that the 10mm screed on top of the perimeter insulation should be fine.

shane6977

10mm is going to crack and break off

L driver

atlonglast wrote: »

I rang the technical dept. again and they reckon that the 10mm screed on top of the perimeter insulation should be fine.

should be a fine thermal bridge!?