Sealing in double glazing ...

Expanding foam and seal from where-ever you can get the foam nozzel or pipe in.

Ah, hadn't thought of that - was thinking of some kind of mastic. Tx.

this is far from clear

that's one way to destroy it

NT

Always fun trying to decide what will go first - will the window sill bulge, will the window go wonky or will a bit of wall fall off? :-)

Low expansion foam ... YKIMS!

decorators caulk

what I'd like is foam with great expansion but too weak to damage anything

NT

With respect to a window frame, that's all of them IME.

Foam has 2 expansion phases - 1st is wet and that obviously puts very little strain on anything as it can extrude.

The other I have not seen a *significant* force exerted.

I've foamed in 7 new uPVC windows with 1cm gaps all round and never had a problem.

I've seen huge force exerted after setting.

NT

What make of foam was this?

wish I could remember. Most likely options are wickes, screwfix or whatever the local hardware store sold.

NT

I use firefoam almost everywhere, ( except where it could trap water and th us rot woodwork, (there's a window frame with holes under it which i'm goin g to use lime cement in so that any moisture can percolate away (when the w eather's warm enough for lime-ing) ) ).

Just an update ...

With Storm Emma blowing -4C air at high speed around the place, I've had a unique opportunity to discover previously unknown draught spots.

Necessity forced me to use air-ducting tape (silver-corded) to seal the aforementioned gap. Result was almost instant rise in temperature ( :( )

Also around the static patio door frame there was a trickle of air (not anymore) again, saw a temp rise.

I idly wonder how much air is being blown under the house - through air bricks, and up through the floorboards, underlay and carpets ????