Stainless Steel Twin Wall Flue Kit – Through the Roof with Offset (1–2 Story House)

Many wood-burning stoves come with the choice of attaching the flue pipe to either a top or rear flue exit. From the stove, you can lead the chimney directly outside, run it upwards first and then outside, or take the chimney all the way through the house.

For the adaptor you have the following options:

Single to twin wall adaptor (also increasing adaptors)

This adaptor can be installed in two ways:

1. Direct connection – push the adaptor into the stove opening so it sits inside the spigot of your stove. From there, connect the twin wall flue pipe above.
2. Connection via stove pipe – install a length of single wall stove pipe first, then push the adaptor into the top of the stove pipe and continue upwards with twin wall flue pipe.

Single to twin wall continental adaptor

A continental twin wall adaptor creates an easy connection of twin wall flue pipe to any European model of stove.

This Continental Stove Adaptor is used if you have a European stove collar, as the sizes are slightly smaller than a standard 5" or 6" stove collar.

• 5" continental adaptor: outside of the adaptor is 115 mm; to twin wall 125 mm (5")
• 6" continental adaptor: outside of the adaptor is 135 mm; to twin wall 150 mm (6")

Passage of a flue through the floor

The passage through a flammable floor can be done with:

- a Ventilated Firestop plate against the ceiling (in practice customers often take a round trim plate for the first ceiling); and 
- a Vented Floor support on the floor. 

The passage through the floor can be done with:

- a Ventilated Firestop plate against the ceiling (in practice customers often take a round trim plate); and 
- a Vented Floor support on the floor. 

1. Put a length through a pre-prepared wood box in the floor and slide down the Vented Floor support plate.

2. Screw this Floor support plate to the box. Next, screw the support clamp directly to the jacket pipe of the length. 

3 Glue the Ventilated Fire Stop plate (or round trim plate) onto the ceiling 

Introduce an offset in your flue (see picture)

Determine how many mm the flue should move sidewards.
To create the offset we can work with elbows of 15°, 30° or 45°. A lower angle is better for the draw.

Wall brackets

Both elbows need to supported by a wall bracket. These brackets can be a roof support and/or a floor support. 

Attention: You need to check if the required offset comes with an upward length that fits under your roof. If it does not; you need to find a solution, most likely go for a smaller offset...

We need to calculate how many straight elements we need going upwards; knowing that we already added some length to the flue through the adapter and the offset.

Step 1 : calculate how high the flue should be on the roof

To determine the required height on the roof (G)  see " Complete information" below.

Step 2: Calculate the total height of the flue (stove to cowl)

Total height of the flue  = B+C+D+E+F+G.   (In case of a 1 storey house; D, E and/or F can be 0)

Check: The total height from stove to end cap should be at least 3.5 meter (building regulation recommends 4.5 meter).

You do not need to have the exact height, somewhat higher is also okay.

Step 3: Determine how much length is in your shopping cart already

In your cart is already:

- length from the offset - Question 4

Step 4: Calculate the length that has to come from the straight pipes

Total height of the flue - what is in your cart allready.

Note: a bit higher is okay, but do not take a lower height.

The choice of the flashing depends upon:

- What kind of material material is covering the roof, and

- The pitch of the roof (0° being a flat roof, 60° a sharp roof)

Automatically we ad a roof support and -when required- a storm collar.

Rubber flashings come in two versions. Choose by the total length of the flue below the roof. Up to 4m, the flue is still hot where it passes through the roof, so it needs the version for flues up to 4m. Longer than 4m, the flue has cooled down more, and the version for longer flues is used.

A finishing plate can be used to cover the opening between the flue and the ceiling under the roof. 

There are 2 types of cap to choose from:

Rain cap
Will keep vertical falling rain out of the flue. In case of side winds, rain will enter the flue. In case of a flue outside this is less of a problem, as it will not floote into the house. 

All weather Cowl
Keeps rain out of the flue. Also blocks downwinds from entering your flue. Downwinds come from higher objects in the vicinity (up to 10mtr), and without this Cowl they will blow the smoke back into your house.

You need to support the flue over the roof if the free end becomes too long and requires additional support. We recommend to use a telescopic support if the free end is between 1,5m and 3m.