ICF - Nudura vs ???

[Nickfromwales]

1 hour ago, Adrian Walker said:

 

Airproofing is an issue/problem with Durisol & Isotex, but not with Velox.

It is with Velox I’m afraid, as the window and door reveals are bridges to outside atmosphere so need a fair amount of detailing to mitigate, also. 
To be clear, airtightness is paramount with ph levels of build fabrics, and some systems offer ‘reasonably good’ AT standards without adding to the mix. 
0.26, 0.27 and 0.28 on builds over recently been involved in are exceptional scores, but beating ( halving ) the shitty standards set out by IK BRegs is still easily achievable with these off the shelf ICF systems.

Knowledge is important, as some minor tweaks and a few quid spent strategically can see you get much better results, if that’s what you wish to attain.

[Adrian Walker]

1 hour ago, Nickfromwales said:

It is with Velox I’m afraid, as the window and door reveals are bridges to outside atmosphere so need a fair amount of detailing to mitigate, also. 
To be clear, airtightness is paramount with ph levels of build fabrics, and some systems offer ‘reasonably good’ AT standards without adding to the mix. 
0.26, 0.27 and 0.28 on builds over recently been involved in are exceptional scores, but beating ( halving ) the shitty standards set out by IK BRegs is still easily achievable with these off the shelf ICF systems.

Knowledge is important, as some minor tweaks and a few quid spent strategically can see you get much better results, if that’s what you wish to attain.

 

Window and door reveals are an issue on with any building system

[Nickfromwales]

15 hours ago, Adrian Walker said:

 

Window and door reveals are an issue on with any building system

Incorrect. 
Smart ply on a TF gives you window > AT junction. Just needs tape to finish.

[Thorfun]

4 hours ago, Nickfromwales said:

Incorrect. 
Smart ply on a TF gives you window > AT junction. Just needs tape to finish.

can you not get just as good AT at the window junction with a membrane and tape?

[Adrian Walker]

5 hours ago, Nickfromwales said:

Incorrect. 
Smart ply on a TF gives you window > AT junction. Just needs tape to finish.

 

The discussion was not about Timber Frame (TF) building systems, but yes Smart ply on a TF gives you window > AT junction

[Nickfromwales]

20 minutes ago, Thorfun said:

can you not get just as good AT at the window junction with a membrane and tape?

That depends upon what you’re sticking the membrane to and where that next stops. 
The MBC ph PIR + rockwool system does exactly that, but the entire dwelling interior is an airtight membrane so kind of cheats out the question of windows / door junctions. 
Traditional membranes need mechanical fixing, liquid membranes ( like the green paint on AT OSB ) need a substantial substrate to be applied to. 
All changes with whichever differing construction method is used tbh. 

[Happy Valley]

We are using Polysteels Warmerwall which is a polystyrene based ICF with metal frame in the core and metal running down the inside of the polystyrene to which you can attach things to like uprights and ply. 

 

We poured the ground floor concrete in today without issue. It will be while until we do the first floor as there is a first floor raft to sort, blockwork tanking and backfilling to do and some easi-joists to go in before the first floor is erected.  

 

[Nickfromwales]

2 minutes ago, Adrian Walker said:

 

The discussion was not about Timber Frame (TF) building systems, but yes Smart ply on a TF gives you window > AT junction

As ever, we digress. ?

On a recent Velox ICF build I recommended a full internal cementitious parge coat, to turn PP the reveals, and to then tape between the PP and the window / door frames.