New windows but forgot the internal sills

[RockyBalboa]

So most of the windows have now been installed on my renovation and plastering is 3/4s complete but I've just realised there are no internal window sills! Windows were supply only and the company states that internal sills are extra.. so be it.. but I assume I can buy them from any building plastics place? If so, does anyone recommend any particular 'type' or thickness?

[Blakeatron]

For internal you can buy pre-primed and shaped mdf cills

[Pheo]

Make sure you seal them well though otherwise they swell up, in my experience.

[jules_s]

They're called 'boards'

[RockyBalboa]

Ah yes, window boards.

UPVC? MDF? Laminate?

[elanfan]

UPVC about 25mm with a rolled front edge if in White they will reflect a lot of light into the room and not need painting. Easy to cut and fit yourself. Silicone them in place use a level and finish with a silicone bead. Reckon if you'd have asked at the outset it wouldn't have cost you any more to the company to fit them. Now they have your money it will.

[wolfracesonic]

Bull nosed MDF window board cut 40mm longer the reveal at each end, 25mm overhang, painted to match skirtings/architrave.

[C0ffin D0dger]

Blakeatron said:

For internal you can buy pre-primed and shaped mdf cills

Exactly what I've used to replace all mine. Wickes are pretty competitive on them for price.

[Rosscow]

Pay the extra and get some nice oak window boards, will look so much nicer.

[RockyBalboa]

I have about 35-50 windows to do but half of those are BTL but still that leaves say 20 for which I could 'upgrade' to MDF or a hard wood.

What's the difference between Foil wrapped MDF and just primed? The former seems 'fully finished' but why is the latter more expensive then?

Foil wrapped:

http://www.diy.com/departments/window-board-foil-w...

Primed:

http://www.diy.com/departments/window-board-primed...

[B17NNS]

wolfracesonic said:

Bull nosed MDF window board cut 40mm longer the reveal at each end, 25mm overhang, painted to match skirtings/architrave.

This. Ideally they go in before plaster but take your time and they can go in after without issue.

[timmymagic73]

As posted above, best done before skimming - it's a pain to fill and profile the boards neatly afterwards.

Window boards come in different widths - invariably none of these will correctly fit the depth of the reveal your plasterers left after dry-lining..... I had to cut most of mine down and reinstate the rebate on the back. Also the reveal can be left with different depths at each side... I realised the hard way I should have found a better plasterer!

I'd avoid foil wrapped, there's always some trimming to be done and if you damage the foil it'll look awful.

Your local builder's merchant will have 5m of primed MDF board for the same price as a couple of metres at B&Q - they'll even lend you a saw to hack it in half to fit in the car!

[RockyBalboa]

Are laminate window boards any good?