Filling gap around badly fitted window

[mikeyw]

Hi,

I'm redoing the seals on a badly fitted bedroom window, I've done the sides with stixall sealant and plastered over. However on the top of the window the gap is quite deep going back about 1.5" and about .75" high. This will take an awful lot of stixal with a plaster finish over the top. Is there anything i could put in this recess before sealing over with stixall to pack it out? Don't want to compromise the seal but it's going to need an heck of a lot of stixall if i dont pack it.

tia,
Mike.

 

[Alastairreid]

Expanding foam.
Finished with 50mm rosewood flatplate.

 

[pinenot]

Expanding foam.
Finished with 50mm rosewood flatplate.

+1...pinenot

 

[joe-90]

A DIYer would get into a right mess with foam - as would most trades. Any cheap filler will do.

 

[pinenot]

If the foam is applied with a gun and expended at a low output you should be fine.
Anybody using expanded foam who are not familiar with it, regardless how much is expended out, it should not wiped it in any way, but left to dry, whereupon it can be easily cut with a sharp knife, I use an old carving knife with a fairly flexible blade and for a sharp corner cut in from two 90 degree directions...pinenot