Fitting window board, do I close cavity below?

HI All,
Do I need to close the cavity before fitting a window board. This is on my garage conversion, the window is 2mtr wide. I have plenty of dpm and was thinking of laying some over the cavity before putting the window board on top.
Anything else I should be careful about when doing this job?
thanks!!
KS

You should close the cavity; I used proprietary plastic cavity closers on all 3 sides of my new openings. Our BCO wanted to see the new lintels in place & how I was closing the cavities before finishing off, doesn’t yours? Or shouldn’t I ask!

I over boarded the cavity closers & lintel with plasterboard, plastered the whole lot out & then simply cut the window boards to size & stuck them down. I suppose you could use a strip of DPM to cover the outer skin & cavity but I would still overboard with PB before fixing the window board. Problem with using a layer DPM is it will be difficult to bond into place & unless you’re going to screw the window board down, the whole lot could easily become detached.

Hi Richard,
I did see these cavity closers somewhere but thought they're more for closing off the tops of cavities under the roof line.
BCO only wanted to see foundation, lintel and the dpc before screed went down.
See my other posts about wall insulation. I've got cavity party wall, part of which protrudes beyond neighboor, he want additional insulation on that wall. That screws me for another £150 for kingspan etc..
Thanks for advice, ok on the pb ontop ofthe closer before the board. Will now check where I can get these closers..
KS

Use something like this:
http://www.screwfix.com/search.do;j...set=UTF-8&howMany=15&fh_search=cavity+closers

or this
http://www.cellecta.co.uk/Cavity_closers.htm

or whatever your local Builders Merchant has in stock.

Thanks Richard, I shall go for the screw fix product. I only discovered this place 3-4 wks back, it's like the argos equivalent for trade or diy'ers.
I'm pretty impressed by their range of products and would have gone there b4 if I would have known, in particualr as most of the stuff I got off the big highstreet boys at sometimes double the prices.
Thanks
KS

Screwfix are not the cheapest around but certainly much cheaper than the big national Builders/Plumbers Merchants outlets which I only ever use if I have to in an emergency. They are just way too expensive for practically everything even with up to 60% discount offered without too much pressure. I now buy practically all my materials & supplies on-line from specialist suppliers’ particularly plumbing & electrical but my other favourite place for things like plaster products & cement is ------ a B&Q trade centre! It’s a shame I’m not a bit older as I could get a further 5% discount on Wednesdays!

Screwfix carry a big range of products which is good if you want to get hold of a lot of different things in one hit & you can get free delivery the next day on most things if you order before 12. I’ve used them extensively for all sorts including large water tanks & central heating radiators etc, I have a truck but it’s much easier letting them hump all the heavy stuff to your door for you! I’ve never had any problems.

Thanks Richard. I got the screwfix version and have already fitted it. I now need to double up on the window board as it doesn't cover the full cavity, the window is quite 'deep' into the wall. Should really have looked at wider window boards.
Certainly would recommend the one in screw fix, no probs transporting in the small car as the 2.5mtr folds in half..
KS