Fireplace installations and flue system installations by Abbey Fireplaces.

Learn how to install your own woodheater.

This fireplace installation section is meant only as a guide and we always recommend that you use the services of an accredited installer. All wood heaters are reasonably similar in their installation requirements (and so we deal mainly with those in this section) but gas heaters have various installation styles depending on the particular unit so please refer to that exact model for flueing information. For example, if you want to see how a Regency P36 gas flame fire can be installed and flued, go to the Regency gas page and find the P36.

Optimum Installation

Heater is placed in central position.

Flue system runs straight up and out.

Flue system is unobstructed by trees or other objects.

Installation is carried out in accordance with AS2918.

House is insulated.

Installation - Single Storey Straight Through

Check roof space above desired position. If there are roof members in the way, either reposition and re support if possible or use a set of bends to find a clear run, or reposition the heater. Refer to clearances on heater brochure to make sure any heat sensitive walls or other combustible materials are well clear.

Use plumb to locate centre of ceiling hole and scribe circle 10.25" or 260mm diameter (for normal 6" to 10" system). Cut hole.

Set drop box in position so it protrudes through ceiling about 150mm or more if you have exposed beams and fix using brackets to supporting roof members and then fix brackets to drop box.

Fit ceiling plate and proceed to lift tiles or with metal roof, find centre and cut hole leaving tabs which can be bent up and used to fix through.

Join the outer flues (three fixing points on each join - stainless pop rivets or short stainless screws) and raise to desired height through roof (min 600mm or higher to beat ridge height). Overall flue height should be min 4.5 meters from heater. Remember the active flues go in with the crimp down and the outer flues are fitted crimp up.

If tile roof, cut tiles and replace around outer flue. At this point flashing can be placed over the outer flue and fixed using silicon. Lead or zincalume can be used for tile roof and a dektite or aquaseal for a metal roof.

Make sure 8" gal outer or middle casing is fixed and properly spaced.

Join active flues and feed through from the top. Secure into heater spigot.

Attach cowl or hat to top of flue using three screws or pops (don't jam the hat on tight-the flues will expand when hot) and apply silicon over screws and join fixings. Check flashing is well sealed.

Make sure heater baffle is correctly fitted and liners are in place (refer to owners manual).

This is a single storey wood heater installation diagram.

wood heater installation with decromesh.

A wood heater installation with a bend in the flue.

Installation - Double Storey Sraight Through

This procedure is the same as single storey except that you will be fluing through an upstairs room and where the flue is situated upstairs should be predetermined. So in this situation it is often better to work from the upper level, decide the flue position upstairs and adjust the heater position if necessary or use a set of bends downstairs to compensate. Having mapped out your flue position, making sure you have required clearances, you can decide whether you use perforated flue or solid metal flue through the upstairs level.

If the clearances are tight or if you will be fluing through a wardrobe, you will need to run a triple system through this section. However, if you have ample clearance, it is always preferable to use perforated flue as it will provide more heat to the upstairs area as well as looking good. Remember any ceiling/floor penetration should be triple flued the same as roof cavities.

The tiles are cut ready for the flashing.

Installation - Wall Penetration at 45 degrees

Its always better to flue straight up and out if you can but if this is impractical or impossible then the next best method is the 45 deg wall penetration.
Now in some areas where the temperature can really drop it is necessary to run triple flue from the inside wall right up to the cowl. This is to ensure the emissions do not condensate when they pass through the outside flue and can be ejected effectively. If you live in a kinder climate where the temperature difference between inside and out is not so great you should at least make sure that the wall penetration itself is triple flued.

Position heater having checked outside run is free of obstruction.

It is preferable to have at least 600mm straight flue off the heater before starting the bend so set the first flue and bend (crimp down) in the heater and using a straight edge and spirit level, mark the position on the wall where the flue will pass through.

Measure wall thickness. The centre of your inside hole will raise by that distance outside.

Cut the hole through the wall. This will vary in difficulty depending on the materials but maintain a 45 deg angle upwards and fit the wall penetration triple 'box' and secure.

Fit inner and outer wall plates. This will make sure the structure so far is locked and strong.

Determine the distance to protrude outside (i.e. is the flue going through the eave or out further to beat the eave) and place outside bend into position.

Measure distance from inside bend to the middle of the outside bend and if you have to cut and join a section of flue take into account the outer small bend so that you end up with the outside bends nicely centred and spaced. Leave outside active bend proud so flues can be fitted and fixed.

Once you have fixed the outside bends you should be pointing in the right direction so it's just a matter of joining the appropriate number of active flues to gain the required height.

Drop the active flues into the bend and fix.

Measure outer flue run (check cowl - level or skirted) join flues and drop over active flues either as one or in sections. Note - if triple fluing fit inner casing first.

Secure appropriate brackets and fit cowl with three screws making sure the active flue is well engaged but not jammed on (the flues expand when hot so they need a little room to move). Check heater baffle and liners.

Installation - Inbuilt Into Existing Fireplace

This type of installation depends entirely on the shape and size of the fireplace
Because no two chimneys are the same, it is necessary to first inspect the chimney for structural integrity and whether the flue can physically fit through.
In the flue section of this site you will find an array of gadgets designed to facilitate the installation in difficult chimneys.
In most cases some brickwork has to disappear before proceeding and the worst scenario may be punching through the outside of the chimney and proceeding as with a wall penetration.
In any case a pragmatic approach is required here but AS2918 and the manufacturers advise that the heater be flued to that standard but if the chimneys internal measurements do not allow the active flue to pass through, then a section of the flue can be 'ovalised' to overcome the barrier. Another method is to remove part of the back of the chimney, flue through the obstruction and re brick or AC Sheet over the hole.
When flues and register plate are located, the heater is placed into the cavity and by reaching up through the heater spigot, the flue or offset can be located.
In the case where a chimney takes a bend, and many do, flexi-flue is an excellent option. Now the top of the chimney is the next consideration. This should be finished off by fitting an outer flue into the top of the chimney, sealing with cement and attaching an anti-downdraught cowl.
As with all installations the finished height is important so check the flue has sufficient height to clear the ridge and is free of any obstructions (trees or overhangs).

Installation - Zero Clearance

This type of installation is the same as a straight through except that a triple flue is required from heater to hat. Manufacturers specifications (in heater section) should be followed in regard to clearances. In Australia and New Zealand as in many other countries, we have laws and building codes to ensure the correct installation of wood and gas heaters and fireplaces that require a flue system. The standard that applies here is AS 2918 and is available from Standards Australia or on the web at www.standards.com.au It is strongly recommended that all installations be performed by a builder or accredited installer who understands and follows these standards.