cavity closers

[pma]

I'm about to fit a pair of 4 foot wide french doors in an existing wall. The opening will be created using a diamond cutter and a lintel of the correct spec will be used to support brickwork above.
I intend to fit proprietry plastic insulated closers in the horizontal wall sections (building regs approved), I assume this is the best and most straightforward method of closure?
but my main question is;

Is there a strengthened or reinforced proprietry closure for the lower door threshold to withstand foot traffic?
Any advice and info on brand/type would be appreciated
Thanks

 

[noseall]

this area is usually closed off with the floor screed or by extending the floor boards up to the sill threshold.

 

[pma]

Thanks.
In my situation the cavity at the new door threshold will be approx 12 inches deep from the DPC. How should I proceed to fill this without affecting the thermal bridge?

I would have thought in this day of and age there would be a simple, strong and quick and efficient solution to this situation. It must be very common. Perhaps there is a 'hole in the market' for a new system?

 

[freddiemercurystwin]

Its true that there is a bit of a gap in the market for threshold cavity closers, they can be tricky to detail, theres nothing stopping you using a traditional closer from the likes of http://www.cavitytrays.co.uk/ click on closer products then click on type H. You timber threshold should be able to bear its weight onto the outer skin, if theres closer exposed at the back of the threshold and it seems a bit wobbly you can always affix a 1mm thk. galv. sheet as wide as the overall closer width over the top to reinforce it. As noseall says in a new build the screed could extend further out and this issue wouldn't exist. Theres lots of different ways to do thresholds.