Window Sill/ Window Board

16 Mar 2009
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United Kingdom
I am building out a single leaf wall to incorporate battens/ insulation/ plasterboard. As the section of wall is below a window this will mean i need to replace the internal 'sill' with a deeper version (from reading the forums I take it what i really mean is 'window board'?).

Is the best way to take out the existing board by cutting down the middle and prizing it out from the centre?

Any other way?

What are the pitfalls?

I'm pretty inexperienced at diy, please help, thanks

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stephen - your centre cut needs to be roughly square ACROSS the width of the window board but at an ANGLE through the thickness of the board. Why? If the thicknes cut was vertical there's a chance that the bottom edge of the half being lifted will bind on the edge of the other half ... jamming. Obviously, you prise-up the ½ that will allow for clearance. This method is particularly useful for thick sills.

Depending on construction (maybe the sill/board is jointed into the window frame) it sometimes helps to do a couple of vertical cut at each end so the board lifts away; any bits of timber left can be chiselled out.

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