ICF Foundation Details - Thresholds

[JohnMo]

I have 5 opening in total.  One is covered in heavy duty tiles, one in oak floor boards, the other three are self leveling compound and carpet.

[Jenki]

Thanks for positive input.   So this is what I'm planning. hopefully put it all together.

 

[Russell griffiths]

That’s better. 

Do you actually need the additional eps outer skin, can you not use a block with thicker outer in the first place. 

Not sure what your external finish is but anything heavy and I would be worried about the load carrying capacity of the extra eps just fixed to the standard block. 

[Nickfromwales]

Yup, much better.

I'd replace the EPS 400 for something a little more rigid, or laminate EPS 400 by bonding on a layer of 20mm of Compacfoam eg so the CF is the material immediately below the threshold.

You're not showing the DPC under the threshold and forming an upstand so needs detailing.

 

Tres bien.

 

[saveasteading]

You need a plastic sheet between insulation and screed,  so might as well move your dpm up.

The radon barrier is already a dpm though.

[Jenki]

5 hours ago, Russell griffiths said:

That’s better. 

Do you actually need the additional eps outer skin, can you not use a block with thicker outer in the first place. 

Not sure what your external finish is but anything heavy and I would be worried about the load carrying capacity of the extra eps just fixed to the standard block. 

Poly steel only do one size block - so EWI to get a U value.   most likely clad, so fixings will go through batten, EWI and into the Steel flange on the Poly steel block.  alternative option was to but EWI on the inside, but my thought was to have more insulation on the outside of the concrete core for it to be more stable to wind and temperature change. 

2 hours ago, saveasteading said:

You need a plastic sheet between insulation and screed,  so might as well move your dpm up.

is this to prevent the insulation lifting during the pour? or another reason.  If it goes between 2 layers then I can staple  UFH pipe direct not worrying about the membrane, (which as you point out is a secondary layer anyway)

[saveasteading]

11 minutes ago, Jenki said:

to prevent the insulation lifting during the pour?

Yes. the screed is generally quite sloppy and finds gaps between insulation and floats it.

I have been at the floating of a whole area and it wasn't fun. Our plumber had insisted on doing the concrete, but it turned out hadn't done it before.

Me to the rescue with the brilliant instruction to stop pouring. Then concrete blocks to keep it down.

 

In theory all your taped joints might be sound, and not stick to someone's boot.  In practice it isn't worth the risk,

 

 

[JohnMo]

If you use PIR with aluminium layer, the membrane keeps the cement in the screed from a chemical reaction with the aluminium, which forms hydrogen and leaves bubbles in the screed.

[Nickfromwales]

9 hours ago, saveasteading said:

You need a plastic sheet between insulation and screed,

Only with a foil faced insulation, not needed with EPS  

[saveasteading]

1 minute ago, Nickfromwales said:

not needed with EPS

I'm not talking about any chemical reactions but of insulation floating.

50p/m2 takes away the risk.

[Nickfromwales]

2 minutes ago, saveasteading said:

I'm not talking about any chemical reactions but of insulation floating.

50p/m2 takes away the risk.

Screed or concrete? Where are the UFH pipes going and how they getting attached?