replacement windows - cut the stone or the window?

[Postie]

We have just bought made to measure windows from Lapeyre (at no mean cost) & now that the old windows have been removed we have a problem with the wooden sill on the new windows. L'appui, as the sill is called, is about 30mm too wide overall. Our options are:

1. Cut the stone & destroy the originality of the window aperture. This is the more difficult option as the sill has to be recessed into the stone. 

2. Cut the window sill & lose the 15 year guarantee. 

Other than the sills, the windows frames are a perfect fit.

 

Any suggestions please

Thanx Postie

[Gyn_Paul]

I'd cut the sill and to hell with the guarantee. So*d's Law you'd end up chipping a great big chunk out of the stone which will bug you every time you look at it for the next 15 years anyway !

Would I be right in thinking the cut ends of the sill will be within the stone cavity anyway ? How would anyone (Lapeyre inspector etc) know you'd modified the windows?

p

[Postie]

Hi P

Thanx for the reply.

Yes, the cut sills will be within the walls. I would seal the wood & point up the stone properly to avoid any moisture getting into the structure.

Postie

[BIG MAC]

I would cut the sill to be about 4mm short each side. Then treat the cut ends and stain/ varnish/paint.  this will help revent water ingressing he end grain from the stone. I would then us a good polysulphide mastic to gun the joint in, this will allow for expansion and contraction while preventing the ingress of water and material which could bridge the gap. If you cut the stone a) you damage the reveal  b) the endgrain will likely take up moisture and start to deteriorate.

[Postie]

Thanx to all for your replys - will let you how it goes!

Postie