Twin Wall flue through the roof with offset- Stainless Steel (1 or 2 story house)

Many wood-burning stoves come with the choice of attaching the flue pipe to either a top or rear flue exit. All things being equal, it’s best for a flue pipe to go up in a straight line in order to achieve the best draw and most efficient burn from your woodburner. 

For the adaptor you have the following options:

- Single to twin wall adapter (also increasing adapters)

To be pushed into the stove opening; sits inside the spigot of your stove and then connect to other twin wall flue pipe above. Or push into the stove pipe.

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- Single to twin wall continental adapter

A continental twin wall adapter creates the easy connection of Twin walled flue pipe to any European model of stove.

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. 

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 a starter length or adjustable connector  (if you did chose one)  - Question 2

- 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.

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.