BISF House Flue Frame Removal Question
Hi, Im new to the forum. We have recently bought a bisf house and are currently Fitting a log burner, we just wondered if there is any way of removing the support frame for the flu leaving just the Flu itself exposed?
Any suggestions would be well appreciated
Hi Dan, welcome and glad to have you on board!
I have to admit that an exposed frame in the living room is certainly not the most aesthetically pleasing by any means.
We could do with a little more information about what you want to achieve, such as do you intend to leave the existing fireplace in and the burner fits into the fireplace (which is probably a little small or are you thinking of removing the fireplace altogether?
The problem here is that the flue is sectional in 3 parts (sometimes 2). The section that is exposed in the living room actually sits in a collar mounted on top of the concrete fireplace support as shown in the image above.
The flue then joins the second section at ceiling height just below first floor level under the floor boards where another steel support plate is fitted. (see image below)
If the original fireplace is removed the lower section of the flue is no longer supported and the flue will separate and will need to be removed along with the lower section of the cage.
You could then theoretically place the wood burner below with its own flue leading up to the remaining flue left in situ.
You would need to ensure that extra supports are put into the flue plate under the remaining original flue to ensure it cannot drop down into the living room. Usually this is done by welding in or bolting in a few sections of steel.
Remember also that the flue plate at ceiling height is slightly proud of the ceiling. i.e the plate sits around an inch below the plasterboard of the ceiling.
You will also need to consider the amount of heat that is given toward the materials surrounding the point where the new flue enters the old flue. i.e the plasterboard / fibreboard, depending on which was used in your house. Plasterboard is safer than the fibreboard when it comes to heat.
I believe you may be able to obtain a thermal collar that should help with this and you would probably need to obtain further guidance from a burner specialist.
I hope I have described this enough, if you need any more details I can try to explain further.
The images below show the retaining collar that sits below the floorboards of the master bedroom and protrudes down slightly into the living room.
Hope this helps (flue images thanks to Ray)
BTW here's a few burners that have been fitted in various BISF houses.