Does this detail look ok?

[flanagaj]

I want to simplify the installation of the Radon membrane and if I can do the below, eg run the lower DPC under the inner leaf and across the cavity and then up the inner face of the outer leaf.  If I can go with this approach, it completely negates me having to use pre formed door openings OR having to try and bodge it together.  The only required detailing will be the 4 corners.



The standard Visqueen detailing is shown below, but if you go with this approach, then you have to mess around at door openings.  I just want to avoid as many taped joints as possible.

[Mr Punter]

Why have you lapped it up the brickwork?  Just leave it flat.

[Russell griffiths]

As @Mr Punter said lay it across the full width and build up from that. 
if you had of brought your concrete up higher you could have just laid it flat across that. 

[flanagaj]

1 hour ago, Mr Punter said:

Why have you lapped it up the brickwork?  Just leave it flat.

Because it’s a Radon barrier and has to span the cavity

[Mr Punter]

1 hour ago, flanagaj said:

Because it’s a Radon barrier and has to span the cavity

 

So can't you do this?:

 

[JohnMo]

Your white  blocks make a nice cold bridge. Just replace with thermolite or similar and it's gone.

[flanagaj]

3 hours ago, Mr Punter said:

 

So can't you do this?:

 

What would that provide over and above the detail shown?  

[flanagaj]

3 hours ago, JohnMo said:

Your white  blocks make a nice cold bridge. Just replace with thermolite or similar and it's gone.

I didn’t show it, but the second course (inner leaf) is a Marmox block

[Oz07]

4 minutes ago, flanagaj said:

What would that provide over and above the detail shown?  

Zero folds

[Tony L]

22 minutes ago, flanagaj said:

I didn’t show it, but the second course (inner leaf) is a Marmox block

 

I'm not thinking that's wrong, but I'm interested to know if there's any reason why you made the middle white brick Marmox, rather than the lowest of the three white bricks?

[Mr Punter]

31 minutes ago, flanagaj said:

What would that provide over and above the detail shown?  

The green line would be your gas membrane, laid flat with no folds or laps, supported on the slab and external walls.  You can add whatever other DPCs you may need, safe in the knowledge that the gas membrane is continuous save for correctly detailed service penetrations.

[flanagaj]

3 hours ago, Mr Punter said:

The green line would be your gas membrane, laid flat with no folds or laps, supported on the slab and external walls.  You can add whatever other DPCs you may need, safe in the knowledge that the gas membrane is continuous save for correctly detailed service penetrations.

That is a clever option, but I would need to protect the membrane whilst the shell is built.

[flanagaj]

3 hours ago, Tony L said:

 

I'm not thinking that's wrong, but I'm interested to know if there's any reason why you made the middle white brick Marmox, rather than the lowest of the three white bricks?

I could be wrong, but my understanding is that the marmox block simply needs to sit at the same level as the PIR insulation.  

 

 

[JohnMo]

That works, but save some money and just use Thermolites. They are in a nice dry area, so will.work well.