Filling Gap under Window

[Spinny]

How do people suggest I fill the gap under my floor level window as shown in the photo ? (Around 16mm)

As you can see the Window was installed onto plastic spacers before being screwed in, so I need to fill between and around the spacers. A porcelain patio is planned to be laid up to the window frame, or possibly with a strip of gravel soakaway at the bottom of the window.

 

I am thinking ideally an element of insulation might be good at the back of the gap to limit thermal bridging at the frame ?

And perhaps mortar mix, or concrete mix, or Toupret exterior rock solid repair filler in the front half of the gap ?

[Andeh]

I wanted expanding foam, but builder insisted on packing it tight with mortar to ensure the packers and window stayed secure. Looking back, I'm pleased I let him. I used expanding foam at the top and sides though. With the movement of the door, if it nudges those packers out post patio install ya'll in for a world of trouble. 

 

 

Edited Sunday at 15:40 by Andeh

[Russell griffiths]

 

pump 3 tubes of this under it, stop 20 mm from the packers and let it dry for 48 hrs

then chop the packers off flush with a sharp chisel, then fill the remaining gap and wipe over the ends of the packers. 
will dry more solid than mortar, won’t crack and fall out. 

[Spinny]

It isn't a door, it is a single fixed pane window about 1.5m wide and 2.4m high.

 

Yes I used foam at the sides, you can see some yellowed and waiting to be cut back flush at the edge in the photos.

I agree it seems best to have something capable of supporting the window from underneath.

 

Would the EBT set hard as it seems to say it is flexible ?

And wondering if it has any insulative value ?

 

The aluminium frame has a thermal break in it, so if I could avoid creating a thermal bridge underneath across the outside frame and the inside frame it might help keep the bottom frame a bit warmer internally. Maybe push in some XPS at the back and then EBT or something at the front ? Or maybe I could try cutting some slivers of celcon block ?

 

[Andeh]

If its just a solid window, without movement... You could just pack it with more plastic packers to add rigidity, and then use construction adhesive to glue them all tightly together, then expanding foam around the rest of it? It's certainly gunna be a lot better insulation wise then mortar, and will still create strong static strength. 

 

 

Edited 11 hours ago by Andeh

[Andeh]

FWIW our big sliders, sat on mortar, are a collosal thermal bridge.