Fitting the smooth board closure plate

As long as your builder’s opening is made of brick or stone with NO combustible materials (plasterboard is classed as combustible) then there are no Building Regs that stipulate the size that your builder’s opening should be and no regulations that dictate any air gap requirement around that stove once it is in the recess. BUT, there will likely be "recommended" air gap requirements provided by stove manufacturer’s unique to each stove (usually in the stove’s installation instructions so download these prior to purchasing the stove). Under-confident Building Inspectors may insist on these "recommended" air gaps even if there is no obvious safety reason to adhere to them.

Why the air gap anyway? To ensure the heat from the stove gets to the room rather than being soaked up by the building (tucked into a small recess the stove output-to-room may disappoint).

What is the height required between the top of the stove collar and the closure plate if two elbows are on top of each other? 30cm covers this but allow 50cm if one elbow has a soot door. Height above stove is rarely mentioned anywhere for some strange reason but I mention it in my article Heat Shields and Distance to Combustibles for Wood Stoves.

Note that different brands of elbows will have different heights when added together to form an offset. You do not want to be going through your closure plate at an angle as the sealing plate will not work. More about offset dimensions in my infographic: Fitting Packs.

Or you use a “T” off the rear of the stove.

But only if your recess is good and wide so you can access it to sweep up through the T (you need to access the soot collecting door which points down to the ground).

Off the back is not so good.

The stove may leak smoke from its open door (whilst lighting) until the fire is established and the chimney warmed.

I now add my vitreous pipe to my adaptor, sliding my adaptor (the male) into my female vitreous pipe. If this is a loose fit use fire cement or fireproof webbing around the snout of the adaptor and secure using three self tappers. Webbing, drill bit and self tappers are included in our Useful Items Kit which is included in our Fitting Packs (everything needed to fit a liner to a stove).

You will end up with something like the first image in this article, with the snout of the adaptor and the attached black pipe dropping through the oversized hole. I like this picture. It almost shows how to fit a stove all in one picture. You can see the hearth, the lining boards, the lintel and now the adaptor dropping through with two offset elbows connected.

Next you will go to the top of the chimney and pull the chimney liner up until the vitreous/adaptor combo is out of the way for the moment above where your closure plate is to go. If the top of the liner has already been secured and scaffolding now on somebody else's house then you are buggered! Not really but it is not now so easy. You just have to use a long-nose adaptor and have the snout hang half way through the Hardiebacker board and put the closure plate on before any side lining-boards. We will look at this situation shortly.

With the closure plate cut to size (usually a square or rectangle) measure the width of the board (left to right) and mark a centre line. Best also measure your fireplace width as this centre line will be where your flue pipe ends up.

You then have to work out exactly where to cut your hole.

You can clearly see the centre line and this dictates where your hole will be (left to right). Where your hole will go forward to back will depend on where the rear edge of your lintel is and where your back wall is – it will be somewhere in between the two.

I used a grinder to cut Hardiebacker. Kenny uses jigsaw blades. It is essentially concrete board so choose cutting device accordingly.

In the picture with the red and blue arrows, the chimney liner enters the arena at an angle from the left and so it has been necessary to add an elbow to the bottom of the adaptor (in my experience this is always a 30 degree elbow). Make sure you connect your elbow to your adaptor with a metal to metal self tapper (we do not want the elbow coming off when the sweep comes).

To avoid confusion “cut edge below bump” means that the installer has cut the female end of the vertical flue pipe and slid it over the male elbow – and this picture shows how neat that can be if done well. Use a grinder with a 1mm thick 115mm diameter metal cutting blade. Often there is no need to cut vitreous pipe (buy it in lengths 250, 500, 1000mm).

There is nothing to stop you fitting your closure plate first, before your side and rear boards as can be seen in the scribble-drawing.

It can be a lot easier as the liner/adaptor is never in the way (you lift the plate UP rather than slide it IN).

All you need is some thin metal angle and use it to support your closure plate.

We did this once on a job when we had to do a very swift closure plate because the hire company wanted the cherry picker back and we did not have enough time to do the rear and side boards.

If there is a big gap (more than a few mm) between the top front edge of your closure plate and your lintel then you will have to fill that gap before using Thunderbolts to screw your closure plate to your lintel. If you do not do this the plate will lift at the front and open up a gap above the side-of-recess boards (small gaps can be filled with Decorator’s Caulking). If it’s only a few mm of gap you might choose not to worry about it. If its a cm then you will have to be creative (e.g. 1cm pieces of copper tube as spacers with the Thunderbolts going through the middle). If, after screwing to lintel, your closure plate rises up at the back a little, then you can somehow weight it down (a couple of bricks fed in through the hole) and reach in through the hole and add mortar in strategic places. If it is only a few mm then Decorator's Calking to fill the gap is fine.

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.

Remove your stove from it’s packaging and assemble it according to its user manual. Most stoves have a rear exit flue hole and a top exit flue hole. Choose which one you are using and fit the stove’s blanking plate to the other with the parts provided (you will usually seal this with supplied rope or webbing or use fire cement). Fit your stove collar (again you will usually seal this with supplied rope or webbing or use fire cement).

You may have to bolt on the stove legs (if you have adjustable legs make sure the adjusters are loosened ready to go – they are sometimes bolts in threads and more difficult to sort out when the stove is in the recess).

Slide everything down so the vitreous pipe inserts fully into the stove collar.

Back up to the top of the chimney where your liner is sticking up skyward a metre or so.

Using a marker pen mark a line about 2cm above the top of your chimney pot. Cut at this point using a hacksaw or grinder or tin snips.

Get your helper to slide the adaptor/vitreous combo up the chimney about 30cm.

Fit your Duraflue Stainless Steel Liner Cowl.

Slide everything down into stove remembering to add your sealing plate around your vitreous pipe.

Use supplied Jubilee clip to attach cowl to chimney pot.

Screw sealing plate to closure plate using four large self-tappers in Useful Items Kit (included in Fitting Pack).

If your cowl is already fitted and liner cannot be moved up or down chimney

Position your stove on the hearth and plan your steel vitreous flue configuration. This may just be one piece of pipe or it may be more complicated.

You can cut steel vitreous flue pipe if required. I use an angle grinder with a very thin metal cutting blade of approx. 1-1.5mm thickness. Make sure you wear long sleeves, eye protection, dust mask and gloves. Please take this very seriously as the thin blades can shatter.