Wood burning stove shed chimney kit Silvacore Duraflue PRO DTW 2.5 Metre (shed, garage, gazebo, home-office or small room): 5", 6", Silver, Black.

What's in the kit?

Choose between black or silver...

Shed kit FAQ

Why fit a wood stove in a shed or other small building?

If like many people, your shed or garage is your refuge, then you want to make it as comfortable as possible. This means finding a way to keep it heated during the colder months. A small wood burning stove is the perfect solution. It can completely transform a cold and unwelcoming shed or garage into a warm and cosy retreat.

What size stove for a small room?

For most small spaces, a small 4-5kW logburner is probably the right choice. You can use a calculator to check what heat output would be best (you’ll find the very gizmo on our home page). This is based on the space inside your shed.  However, unless you have a huge shed or garage, a 4kW or small 5kW stove is probably the right size for you. While small, it will produce a lovely cosy fire and plenty of heat. Or choose a smaller 5kW stove and put less wood in it! Some stoves have integrated log storage which can be handy, as it will save you from going out in the cold when your stove needs topping up with combustibles.

How close can my stove be to the walls of my wooden building?

Best to read our distances to combustibles article. A stove will often need be 60cm to 100cm from wood without a shield.

Do I need a hearth for my shed?

A simple slab from the outdoor yard of your local builder’s merchants will suffice (ideally 84x84cm minimum as this is what building regs says). It is important, if your floor is wood, you choose a stove that can sit on a 12mm hearth (most of ours can - see specifications or use our search filters.

What is twin wall flue?

Our kits use clip-together insulated flue pipe which is generally referred to as "twin wall". It is two skins of metal with about an inch of insulation (Rockwool usually) sandwiched in between. Is a twin wall chimney safe in a shed? Twin wall pipe generally gets no hotter than a radiator. Because it is insulated the clip-together insulated flue pipe can be as close as 5cm to wood and is completely safe (7cm if the flue is boxed).

Can I legally fit a wood stove in my shed, garage, gazebo, caravan?

Regarding permissions or certificates you do not need permission if the property is not "habitable". Who defines whether something is "habitable"? We do not have an answer to this. As a general rule Building Control are not interested in garden rooms, sheds, garages, boats, vans and caravans etc. Of course if your garden shed is the size of a small bungalow with bedrooms and carpets then you might wish to talk to them :-)

Is this job an easy DIY task?

Installation is probably a lot easier than you might think. DIY wood stove install is not a difficult task as the chimney system is "clip-together" and because it is a shed we are not working at a great height. The twin wall is super easy to install - the chimney parts just clip together and the bottom of the chimney inserts into the stove with a wrap of sticky-back fireproof stove pipe webbing (supplied). Ever heard of Meccano kits ? You get the picture.

Can I use the thinner uninsulated pipe called vitreous pipe?

Single skin vitreous pipe must be kept at least 15-18" away from any combustible materials so is not usually suitable. This gets very hot indeed and can set fire to combustible materials if they get too close and hence we do not sell this within our kit (we can as a bespoke design). Because twin wall pipe has clip-on locking bands a chimney made only of twin wall (without vitreous pipe at all) is very strong structurally. Hence only one wall bracket is required. We often get asked if we can use vitreous pipe instead of the insulated twin wall for the first metre above the stove. We can BUT the joint is weak (wobbly) and this can only be rectified by having multiple twin wall brackets instead of one (chimney strength comes from at least two points of contact with the building).

What diameter hole will I make in my shed roof?

Twin wall has an outer diameter of 192mm and 6" has a diameter of 217mm. If passing through a combustible surface (felt/wood etc.) your hole diameter in the roof will be 300mm for 5" twin wall and 325mm for 6" twin wall. This provides an air gap of at least 50mm all round your flue. If you are going to box in the pipe where it passes through the roof (create an enclosed space where heat can build up) please ensure you have a 70mm gap around the flue)

Which kit should I choose?

Click the more info button next to the different options as it explains all.

What if I need more height?

Go to Product Addons and add extra lengths in 25cm, 50cm, 80cm or 100cm. Add one narrow locking band for each part purchased.

How high above my roof surface must my chimney be?

A minimum of one metre. Also worth watching our 6-minute chimney design video.

The part that seals the hole in the roof, the flashing - what type of roof is is suitable for?

It is an Ezi-Seal EDPM flashing for felt, metal, GRP, rubber. Almost any flat or undulating surface except tiles. It has a pliable flange suitable flat or undulating surfaces (e.g. a corrugated metal roof).

My roof is tiled - what flashing to choose?

If you have tiles then find the product “Customise Your Shed Kit” and upgrade your flashing to “aluminium or rubber for tiles” (two separate flashings).

How do I hide any hole from the inside?

Choose a Finishing Plate from Product Addons on this page. We do not include it in the kit as some do not need this part.

What exactly is in the kit?

1x stove to twin wall adaptor, 2x 1000mm twin wall straights, 1x 500mm twin wall straights, 1x twin wall weathering cowl, 1x roof flashing EDPM ezi-seal, 1x adjustable bracket 95-135mm, 4x narrow joint clamp (connects parts together), 1x fireproof webbing (for adding to snout of twin wall where enters stove).

I am worried about my roof leaking, can you reassure me?

The flashings we sell are easy to install and leakage is zero when installed properly. Everybody worries - then we hear back that all went well.

How do I connect the Ezi-Seal flashing to my roof?

Very simply you screw it or bolt it. Most use screws. If screwing into wood use wood screws. If into metal use roof ing screws. No Silicon adhesive required.

The adaptor that fits to the stove - tell me more.

This twin wall adaptor is supplied with the kit and is the lowest part in the system and connects directly to the stove. The snout of this part can be cut shorter so it is all hidden within the stove collar. Wrap fireproof webbing (included with the shed kit) around the snout before sliding the snout snugly into the stove, No fire cement then required. This part is always a loose fit. Manufacturers undersize the snouts to fit ALL stoves. Stove makers oversize the collar to fit all pipes and snouts. Best to use fireproof webbing wrapped around snout. Fire cement works but cracks and falls out over time.

Is 2.5m enough for a chimney?

In an ideal world we would have 4.5 metres. But modern materials allow us to push the limits and go shorter whilst retaining the required amount of draw. Think about adding an extra half metre if it will not look silly.

Customer's installs

First, you choose the location. A heat resistant base is placed on the floor (the hearth). Hearths should be a minimum of 12mm thick (or 125mm thick with some stoves) - please see a stove's product page.

If you are following building regulations, the hearth must be a minimum size of 84cm x 84cm square (one large slab or a jigsaw of smaller pieces). That can seem overkill in a small room but if choosing to go smaller then make sure there is a minimum 30cm of hearth in front of the stove door (if a stove asks for more then follow what it says but more than 30cm very rare). The 84x84 is building regs size for inside a habitable room. Non habitable rooms (e.g. sheds) it is up to you but we recommend 6" around the stove minimum and 30cm in front of the stove to catch any embers that may drop out the door (also the floor in front of the stove can get very hot).

It is best to bed your hearth down on a thin sand/cement mix. You can though just lie the slab straight down on the floor (more chance of a slab cracking without the sand/cement mix though - but unlikely unless undulating surface under flat slab).

If choosing slate or granite go for 2.5cm or 3cm thick for strength so it does not crack under the weight of the stove. Visit your local builder's merchants "outdoor yard" lots of slabs and slates and tiles to choose from (some very cheap but can look really great - shabby chic and all that).

Next, heat shields are placed on any combustible wall/s near the stove to protect the wall/s from getting too hot. Follow the distance to combustibles link for more... It is the air gap that protects the building and not the shield. Quick read of this subject matter is further down this page. Stoves, Vitreous Pipe and Twin Wall pipe all have different distance to combustibles requirements.

Place the stove in situ.

A hole is made in the roof (or wall) for the flue pipe. In the wall or sloping roof this will be an eclipse (egg shape) but a flat ceiling it is a round hole. Leave an air gap of a minimum 5cm all around the flue pipe (7cm if boxed in e.g. when passing through a void). Hole size should be diameter of pipe plus 50mm air gap all round for safety (70mm all round if pipe boxed in and not open to the air). So that's 100mm extra on the diameter, or 140mm extra on the diameter.

5" twin wall has an outer diameter of 192mm and 6" has a diameter of 217mm. You can leave any void as just an air gap or fill any wall or ceiling void/air gap with Rockwool afterwards. Use Rockwool as it is A1 fire-rated (will not catch fire).

To work out which way up your flue pipes go (which is the top and which is the bottom?) attach the cowl to one of your lengths (cowl is the witch's hat that stops rain entering the chimney). The cowl will only fit to one end and once done you know which is the top of a length of pipe (it is the end that happily fits to the cowl!).

Twin wall parts connect to each other using narrow locking bands. That is it. No sealant or glue of any kind required. No sealant or glue is required anywhere on this install.

The first part into the stove is the "stove to twin wall adaptor" - that is the part above the cowl in the picture of all the parts). This adaptor is usually 4" to 5" or 5" to 5" or 5" to 6" or 6" to 6" (if the snout does not fit INTO the stove hole then you have the wrong size). It can insert into a stove or into vitreous pipe and acts as the 'transition' to twin wall "clip-together" chimney parts. You might wish to have a play and clip your adaptor to the first length of twin wall "clip-together" pipe with one of the supplied narrow locking bands (choose a 500mm length or a 1000mm length up to you - we supply both so you can juggle around to avoid having a joint hidden in a ceiling void which is not good practice).

The adaptor is a loose fit in the stove (they always are) "like a pencil in a bucket" (exaggeration). The adaptor has a "snout" that goes inside the hole on top of your stove. The snout can be cut down if too long using a grinder and 1mm thick metal cutting disk (wear goggles and gloves). You can smear Fire Cement around the snout to seal the gap if you wish (the old way). This is water soluble so you can wipe away any excess using a damp cloth. It will not harden until many hours have gone by or the stove is lit. But fire cement dries a horrible light grey colour and cracks and falls out the gap over time. We recommend wrapping fireproof webbing (supplied) around the snout (one layer should be enough but double-layer if required) and sliding the snout into the stove. Do not over-worry how airtight this is - imagine an open fire in your local pub: a great gaping hole open to the room . Chimneys suck from the top: smoke does not escape through gaps unless the chimney is blocked or a sudden downdraft and if that happens the smoke would pour out the air vents of your stove! You can drill a hole the size of a 50p in your flue pipe and it will suck air into the flue and not the other way around.

Fit your flashing. This is, by default, an EDPM Eaziseal flashing: screws to a roof using wood screws (if roof is made if wood) or metal roofing screws (if roof is made of metal). You will drill pilot holes in the EDPM flange to take the screws. With the Ezi-seal flashing no glue/silicon/sealant is required.

If you have roof tiles then you will likely have chosen an "Aluminium Rubber Flashing" or lead aluminium flashing. Installation of this flashing involves removing tiles, fitting the flashing and then replacing the tiles. Best bet here is Google the subject. With both flashings you will have to cut your required hole size in the black rubber "nungy" (a word from schooldays I think... hope it's not rude).

Hide the hole inside the building with a finishing plate (not supplied) or make your own out of Hardiebacker board from all good building merchants. A few dots of silicon will stick this to the wall or ceiling.

If passing through a wall it is the same with the outside of the building (if outside is not completely flat you may have to create a flat area using Hardiebacker board or similar. There is no "defined method" for outside as so many different surfaces.

If your chimney has more than 1.8m unsupported flue then add a Wide Locking Band to the lowest unsupported joint (in addition to narrow locking band and it goes over it so two locking bands on one joint).

Fit your bracket/brackets.

Fit a Carbon Monoxide Detector.

You should have a small bag with the fireproof webbing. If not we messed up and forgot to send it - arrives in the post.

Any questions Julian is usually on Live Chat (hours at top of website). Or you will get Julian's right hand man... Henry.

Easy peasy! Okay there's a few things to think about - but it is not rocket science.

Heatshields

You can fit any non-combustible board to a wall to protect it from heat. It is not the board that protects the wall but the 25mm air gap between the wall and the board (prevents heat transfer and the gap refreshes itself with cooler air due to the fact heat rises).