Thanks everyone for the replies. Particularly with my questionable maths!

<blockquote><cite>Posted By: djh</cite>The load is transferred through the compacfoam onto the rebate in the slab that it is sitting on; there shouldn't be much load on the Isoquick insulation.</blockquote>

djh,

I'm actually trying to sit the door onto the insulation layer as I was concerned about the potential cold bridge if it sat straight onto the concrete.

My detail below, it's a little unclear (as the section is cut through typical wall, not opening - plus it was drawn at A1), but you can see from the adjacent plan that the door line sits around 240mm out and the slab only extends to 175 beyond the same line. I'm intending to follow the Isoquick detail and recess the compacfoam into the Isoquick but still tie laterally into the concrete. Thanks for explaining why this is needed.

Posted By: Doubting_ThomasI'm actually trying to sit the door onto the insulation layer as I was concerned about the potential cold bridge if it sat straight onto the concrete.

In that case, you need to repeat the stress and strain calculation for the Isoquick insulation, and worry about stress concentrations at material junctions.

Posted By: djh
It should be the width of the door times its thickness, 2.6 x 0.2 I presume = 0.52 m². So the stress is 3413/0.52 = 6563 N/m² or 0.0066 N/mm², which is way less than the max working stress of 1.01 N/mm².

It's perhaps a bit different with the lift+slide leaf. This typically sits on two bogies - one at each end of the door - increasing the stress at each end of the door. When slid fully open, nearly all the weight is going to be on one half of the door (since the opener is sitting "in front of", instead of "next to" the fixed glazing).

Perhaps that explains the apparent over-spec - concentrated stresses at the bottom of the threshold could reasonably be 20x the uniformly distributed load I think.

I decided to put nominal 600 kPa insulation under the slider portion of my lift+slide door (i.e. the inner 100mm), with the outer 100mm (fixed pane) requiring much less 150 kPa (e.g. standard PIR) being OK by my reckoning.

Posted By: TimSmallIt's perhaps a bit different with the lift+slide leaf. This typically sits on two bogies - one at each end of the door - increasing the stress at each end of the door. When slid fully open, nearly all the weight is going to be on one half of the door (since the opener is sitting "in front of", instead of "next to" the fixed glazing).

I take your point that the weight isn't evenly spread, particularly when the door is fully open, but I think the runners spread the weight fairly well.

Perhaps that explains the apparent over-spec - concentrated stresses at the bottom of the threshold could reasonably be 20x the uniformly distributed load I think

I'd be surprised if it was as much as 20x but the over-spec is getting on for 200x