If your adaptor/vitreous combination is slid up the chimney out the way the rest of the job is easy. If cowl already fitted and you cannot get to chimney pot jump to next section. But I can't find any information as to WHY one might do this. Can someone shed some light on the situation please? I'm trying to determine if this is necessary (or at least beneficial) for my situation. The added benefit of doing all this will be that if you ever decided to use that fireplace for a wood burner, providing you choose a stove fit for the purpose of your fireplace and room, the chimney is set up ready for a flexible flue liner installation, which should inevitably save you some costs toward the installation. 2019-05-06T20:30:02+01:00 We will look at these two scenarios separately but if you are a number 2 ;-), then I would still read the instructions aimed at the number 1’s as a lot if this is relevant. You will need to paint the surface of the inside walls of the recess and one side of the cement board with a PVA mix (3 water to 1 PVA). This is very important as without this stage the bond between wall and board may not be good.

For example a dramatic code change occured in 2003 NFPA 211. The manuals with that stove, could be printed in 2001 and they will not update the manual till re-certification occures Because the stove is directly connected to the flexible flue liner, the closure plate isn’t required to be sealed in the same way as a register plate. Also I asked why he smashed out the complete housing and not just cut out an area big enough for the stove pipe to go up, then I would have at least had the rest of the damper housing and damper flap to close off a huge section of the hole. The round circles are “dri wall adhesive” and the smooth white area is board. Dabs flatten when board is pressed against them

Closure plate – your inglenook is unlined (brick/stone/rendered etc.)

The attic scenario does not compare because you cannot have a sealed attic- there are always sources of airflow, and sources of humid air in an attic. Open and close the door on a cheap Chinese stove. Then open and close the door on a DG stove, Arada stoves, Woodford stoves, Hamlet stoves or Saltfire stoves. You’ll understand the difference. An example of this is the high effeciench gas furnaces and hotwater heaters, use schedule 40 PVC drain pipe to direct vent there furnaces. The pvc pipe manufactures only test and certify their pipes for water flows and pressures. ITs up to the furnace manufactures to test the drain PVC pipe for their application.

Measuring from this center line and on the line 1” in from the front, mark at 1/2 the measurement #1 in both directions (in the example, we would use 18” from each side of the line. Then make another mark at 1” past that line (or 19” from the center line). NFPA 211 changed the Cross-sectional code for venting in to a larger flue. The former code allowed 3x the flue collar cross-sectional area . If your recess is all over the place then you will probably have to make it up as you go along. One method is to cut the closure plate as close as possible to the shape of the recess (maybe in two or three pieces if it is proving difficult in one). Then wedge or prop it in place and insert strategically placed Thunderbolts as “pegs for the board to sit on. You can hide these pegs by smearing mortar into your corners. If you have room then adding access hatches to the plate means you can add mortar inside the chimney, on top of the plate (or you might be able to reach through your flue hole if you can get the liner out of the way).The Roxul caused a smell as it first heated up, but this seems to be a one time occurrence. I’m pleased with the results of just the insulation, which slow down the heat loss. I’m thinking the metal plate will “air seal” the opening.