I'm at the point where i need to stick PE expansion foam around the perimeter ready for the DPM and base slab.

I've got a few places where it will cover rough edged bricks and some broken concrete edges, so probably going to be a pain to adhere to.

 

Will low expanding foam be suitable for sticking the PE foam in place or am i going to need to buy something specific for the job?

Use Soudal Low Expansion foam. This one:

 

https://www.screwfix.com/p/soudal-soudafoam-expanding-foam-gun-grade-750ml/5026D?

 

Careful as the "ordinary" Soudal foam can looks similar but obviously doesn't have low expansion written up the side!

 

You'll need a foam gun.

 

Dampen the substrates first with water in a plant sprayer.

 

Lines or zig zag the foam on one surface and press the pe (I used eps) against/on it. Use a board against the pe with some bricks against it to keep the board dead straight/flat.

 

 

You can see the house bricks I used just to keep the eps in place whilst the foam sets:

 

 

This is where I stuck some insulated plasterboard down onto a sill using low expansion foam:

 

 

(Novel use of wire coat hangers by the original "builder" as cavity ties  ).

 

Bricks on a spare bit of eps to protect the face of the insulated pb underneath:

 

 

I even stuck insulated pb to the blue dpm I lined the reveal with. The blue dpm was stuck to the wall with spray contact adhesive:

 

 

 

Edited March 18, 20197 yr by Onoff

Excellent news. ?

 

I've already got the soudal low expanding foam and gun. It's ability to stick to everything whether needed or not gave me the thought that it might work for the PE foam.

Wetting will be covered, I was planning on spraying the substrate with water to remove the dust and whatnot beforehand.

 

Did you leave the foam to go off for a few minutes before sticking your boards?

 

Which spray contact adhesive did you utilise for the DPM in the reveal? I can see that being useful later on.

 

Those coat hangers are, umm, novel.

Is the pe foil faced? Not sure if foam sticks to foil...

 

Spray adhesive was just No Nonsense. I did clean the dpm first with Multi Solve.

 

 

 

 

Is the pe foil faced? Not sure if foam sticks to foil...

 

Spray adhesive was just No Nonsense. I did clean the dpm first with Multi Solve.

 

 

 

 

Just realised I used some Nemesis spray adhesive from S'fix too...Not sure what for, will try and look back on the thread.

Looks like I stuck the insulated pb to the dpm with Sika EBT around the edge and low exp foam in the middle.

 

 

Helped by screws at the front.

Foam sticks to Foil on the PIR with no problems. 

Done some today. I think i've found something that foam doesn't completely stick to!

It's grabbing well enough to keep it in place though, so good enough for me.

 

Cleaned and wetted the wall, foam to back of PE and then propped a plank up with blocks and wedges.

 

 

 

 

 

Try the cheapo S'fix spray adhesive if the foam won't have it. Try on a small area first. Looks like perimeter strip is it? 

1 minute ago, Onoff said:

 Looks like perimeter strip is it? 

 

Yes.

Just an expansion piece for the base slab. 200mm of insulation to go on top of the base slab. Above that will have whatever the maximum width of insulation i can use around the perimeter of the heated top slab.

19 minutes ago, Digmixfill said:

 

Yes.

Just an expansion piece for the base slab. 200mm of insulation to go on top of the base slab. Above that will have whatever the maximum width of insulation i can use around the perimeter of the heated top slab.

 

If you're not having UFH in the base slab why the perimeter strip of insulation?

 

Not like it's going to heat up and expand....

 

 

The 10mm movement joint for the base slab is in the floor detail on my plans.

3 hours ago, Digmixfill said:

The 10mm movement joint for the base slab is in the floor detail on my plans.

 

Fair enough.