Best filler choice around refitted windows - not using inner strips.

I'm having replacement windows fitted next week and i'm not having the internal strips fitted to fill/cover the gap between the window and the inner reveals. I'm choosing to fill to make things look cleaner and better to the eye.

I'm going to do the filling myself to save money and the fitter suggested 'Fine Fill' - but mentioned there was a risk of hairline cracking (which i accept).

I wondered if there was a better, more suited alternative for this type of fill - i.e. between plasterboard and UPVC (expect it to be approx between a 10mm gap - but that's a guess).

Thanks.

 

Thanks for the reply.

You're not my builder are you? - he's given me, quite rightly, the same warning about hairline cracks. (i think he will lay in wait to tell me 'he told me so!' after the renovation is completed.) But, he did say they would be hairline...

Problem is that my wife won't entertain the trim - it was that or aluminium windows and the renovation costs were already causing my wallet to require resuscitation. So filler compromise it was/is...

My theory (rightly or wrongly) is that I'm used to hairline cracks around my existing windows - and hardly notice them - but we both really notice the trim. Plus, when i decorate they get tarted up, filled and look smooth for a few years. (If this requires a bit more attention around the windows every couple of years i wouldn't mind.)

I figured I would experience similar cracking and was hoping that a suitable filler - a slightly forgiving one (not caulk) - would help limit the severity of the cracking?

*Unless you're implying it will crack severely - which would be a different matter...

 

Ahh, good tip - i'll suggest to my builder, thanks.

So a shallow fill (slightly depressed ) of caulk with a skim of plaster/Fine Fill over the top?

Sounds logical to me - the uninitiated - thanks.

 

Good point - missed that.

Would probably need to be the former as i expect the gap to be reasonably wide - not sure if caulk on it's own would smooth out without getting depressed (which would make me sad ). But i'm unsure about this?...

 

I'm anticipating 10mm minimum - would that be too small for foam?

Apologies for all the questions.

 

Thanks, Dr Bodgit, I'll suggest this to the fitter.

I may have to practice on some bricks outside - I've never used foam. But if it were to work it would save a lot of time on fiddly filling - with only needing a thin skim over the top.

 

Blimey - i didn't realise the thermal expansion would be so great - thanks for the data.

Thanks again, KIAB (you've helped me before on a previous/related thread), that may be the ideal compromise. On reading the tech data on paper it seems the perfect compromise.

 

EDIT: Would i be best using a combination of Dr Bodgit's foam first - applying an underlying layer of foam to fill most of the depth and then applying a thin Hybriflex fill over the top?

 

Thanks - is paint adherence a problem?

Really appreciate the extra info - sounds an ideal solution.

Does it dry and then sand - or does it need to be applied like silicon and then smoothed carefully with a finger/sponge or special dedicated tool that i know not?