We're building an extension and as part of that have done away with the original brick chimney in favour of a freestanding install, comprising mainly twin-wall flue.
I'm reading Document J, but it reads exactly as though it was written by someone in a suit that has never been near a flue, but instead digested a thesaurus.
I'm well aware of the obvious points, but need a bit of guidance regarding a couple of things :-
I'd planned to install an air vent to supply air to the stove, in order to prevent draughts. This is to be a 310x29mm flat duct, terminating at a 100mm round spigot. This was to finish directly under the stove, either with a hit-miss style grille, or better still a direct air closed combustion kit. It's a bit tricky as we haven't chosen the stove yet, so planning the exact position of this vent is difficult. Obviously I favour a closed combustion kit, but if we finish up with a grille, is it OK for this to be directly beneath the stove? Document J indicates that it is preferable for it to be outside the hearth area, but it doesn't clearly state whether this is a requirement or a recommendation and just refers to draughts upsetting the dust/ash.
The flue will pass through the loft space and out through the tiled roof. I'm OK with all of this, but, due to the shallow pitch of the roof (15 degrees), it is proving very difficult to get enough length on the flue. I reckon it will finish at about 3.5-3.8m. I know 4.5m is preferable, but will sub 4m really cause a problem? Taking into account that I'm going overkill on the air supply and it will be a decent quality stove too. I could put more than a meter of flue outside, but I don't want to look like a fish-and-chip shop. Also, greater than a meter will want additional support I guess, which is tricky with the shallow roof.
How big a hole needs to be cut in the plasterboard ceiling to pass the 200mm twin wall through? Does it need 50mm clearance all round? Therefore a 300mm hole?
Thats all for now. Any help appreciated.
I'm reading Document J, but it reads exactly as though it was written by someone in a suit that has never been near a flue, but instead digested a thesaurus.
I'm well aware of the obvious points, but need a bit of guidance regarding a couple of things :-
I'd planned to install an air vent to supply air to the stove, in order to prevent draughts. This is to be a 310x29mm flat duct, terminating at a 100mm round spigot. This was to finish directly under the stove, either with a hit-miss style grille, or better still a direct air closed combustion kit. It's a bit tricky as we haven't chosen the stove yet, so planning the exact position of this vent is difficult. Obviously I favour a closed combustion kit, but if we finish up with a grille, is it OK for this to be directly beneath the stove? Document J indicates that it is preferable for it to be outside the hearth area, but it doesn't clearly state whether this is a requirement or a recommendation and just refers to draughts upsetting the dust/ash.
The flue will pass through the loft space and out through the tiled roof. I'm OK with all of this, but, due to the shallow pitch of the roof (15 degrees), it is proving very difficult to get enough length on the flue. I reckon it will finish at about 3.5-3.8m. I know 4.5m is preferable, but will sub 4m really cause a problem? Taking into account that I'm going overkill on the air supply and it will be a decent quality stove too. I could put more than a meter of flue outside, but I don't want to look like a fish-and-chip shop. Also, greater than a meter will want additional support I guess, which is tricky with the shallow roof.
How big a hole needs to be cut in the plasterboard ceiling to pass the 200mm twin wall through? Does it need 50mm clearance all round? Therefore a 300mm hole?
Thats all for now. Any help appreciated.
