Replacing Tiled Window Sill with a Window Board

[comfortably_numb]

I have this bright idea of replacing the window tiles for window boards, Being the novice i am, i ring local merchants & tell him what i'm doing & can he supply the boards, no rpoblem he says pop down & i'll cut to size.

I proceed to remove the tiles & i am left with a bare window sill with 2 cut outs at the bootom of each reveal (i'm hoping this makes ense to someone). I pop down & pick up the boards, get them home & find they are an inch less in depth & also to thick to fit into the reveal "cut outs" either end.

Am i missing something here ?? because the shop didnt mention that the boards come in different depths & do i use the reveal "cut outs" .. if not, how do i get the boards to overlap each end ??
The window board also has a lip ... what is this for ??


Any advice i would be greateful for

 

[noseall]

window boards should be cut 80- 100mm wider than the reveals to show 40-50mm past each reveal. these small returns should have their edges planed and sanded the same as the front bull nose to match.

m.d.f. pre primed boards can be sold in up to 5m lengths, and in widths of 225mm and 300mm. the 300mm wide board will deal with most wall cavity sizes. they are 25mm thick.

the machined tongue at the back edge of the window board would slot into a re-bated groove machined into timber windows only. upvc windows do not have this groove.

if the window board sits too high on the window then remove some of the material below and re-plaster the sill. you will also need to chase in the window board a little, into the reveal plaster. it always looks better if you skim the window board in.

 

[comfortably_numb]

thankyou