EWI window sill finish options

cpoh1

Hi lads, the sister in law is looking to renovate and is going with external insulation on her bungalow, she wants to finish her sills with limestone to match her front steps and drive.

Is it possible to install limestone sills with EWI? She is replacing and pulling out windows also.

If not are there limestone or granite "effect" sill covers available?

Thanks!

cpoh1

Thought there were loads of people on here with experience with EWI

PROJECT K

short answer, anything is possible but to do this would create a very complicated detail trying to deal with the inevitable heat draining thermal bridge. Personally I wouldn't try to match in with the front steps and go for a nice sharp powdercoated aluminium sill that is standard practice for EWI applications - these can be in whatever colour you like but typically replicate the window frame. Alternatively you could install an XPS (extruded polystyrene) sill and have it coloured with whatever colour you like. I have seen granite effect renders on XPS sills and while its a mile away from what I would like personally it looks ok - it will never be mistaken for real granite or limestone though. See attached image...

cpoh1

Is th4e picture attached an XPS sill Project K? Would it be possible to paint the powdercoated aluminium sill?

PROJECT K

yes its an XPS sill with a polymer modified render - effectively the same as the main house but the contractor put a slightly different aggregate into the mix (and different colour obviously). Normally you would decide the colour for aluminium sills and it is powdercoated to the RAL colour you wish. You could re-paint them if you wish but would be difficult to ensure the same quality finish as a factory applied PPC coating.