New UPVC sashes what's Best sealant to buy?

[boomish69]

I have some really nice UPVC sashes coming, whats the best sealant you can buy for the installation? Also as the old sash boxes will leave big gaps on the inside , what filler do you use? Eg foam filler

Appreciate any advice I've never fitted them before.

Alan

 

[hillw]

I would recommend Soudal sealant, I always use the Silirub 2, it is a bit more expensive than some others on the market, but is a pure silicone, no fillers.

As for the inside, are you really talking about gaps, or do you mean the reveal liners.

Foam is okay for filling, but then you would still need some kind of trim to finish off your installation.
You can now buy ogee UPVC arch's in white which would finish off the inside after you have fitted the windows.