Cracked floor under UPVC door

[Louis.]

Is there a reason I can't just use a cavity closer and then screed over this?

 

[Wayners]

Cavity closers are not ment for a floor as far as I'm aware.

Thread here you can read.

Floor Screed over a Cavity ? (New French Doors replacing Cavity Wall)

Background: Old Cavity wall (which had a single door in it), has been removed, ready for fitting new wide french doors. The brick course where the door cill+frame will go has had to be "shaved" by 15mm, to allow the frame to fit (after helpful advice on here). [Note - on the photo, the bricks...

www.diynot.com

 

[Louis.]

Just to double check before I buy the materials. I had planned on filling the cavity with sharp sand below interior DPM, creating a DPM trough that I then pack out with celotex. I'll use this to then fill with concrete covering door lintel and bringing level with remaining bitumen on floor.

I'll then apply a liquid DPM over the entire floor surface.

Does this sound okay?

How would I go about creating the trough so that it doesn't leak concrete?

 

[Louis.]

Any help on the above please?

 

[Mr Chibs]

I would push some celotex PIR (or expanding foam) down there instead of concrete, this will break any potential damp to the inside skin.

 

[Louis.]

I would push some celotex PIR (or expanding foam) down there instead of concrete, this will break any potential damp to the inside skin.

I'll be packing it out with celotex within the DPM.