fireback and throat width question

Hi - a quick question about throat width for an open fireplace, which according to regs (doc J) should be 10-12cm.

I'm using a 22" wide fireback. Nobody seems to sell a throat-forming lintel for a fireback wider than 18", so I'll be casting one of suitable width using refractory screed. I'll also be making 2-3" of extra depth to the fireplace itself at the front.

So if I just did things the lazy way, the throat would be 16-18cm wide, which is far too wide to get a good draw and would fail to meet building regs.

My question is: in order to get the 10-12cm, should I narrow the throat at the front (quite easy, because I just need to make a deeper throat-forming lintel) or at the back (e.g. cobbling something together with firebricks poking out from on top of the infill, made good using mouldable firebrick or fire screed)?

My main concern is not to let smoke come into the room, so I think the answer is probably to build up 5cm at the back. Am I on the right lines? :-) Any advice would be much appreciated!

Thanks! Harry

Reply to
Harry Davis
Loading thread data ...

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.