Installing a wood burner in my workshop advice needed

[Dreadhead]

Winter is here, and I'm freezing my dreads off.

I've got my hands on this nice wee wood burner and a few lengths of single wall flue. I could do with some advice on the fitting. I need to buy a couple of extra bits but can't afford much so trying to work out what I need bare minimum.

Hearth: I have concrete floor so I'm planning on just making a simple hearth from paving slabs or slate. Any advice on what to use to level paving slabs onto my concrete floor? Should I just bang some sand down or do I need sand/cement mix or would a wee bit of stove cement do the trick just to stop any wobbling.


Flue: I know I need to get some extra lengths of flue and some bends. I'll avoid 90 bends and laying anything horizontal.

As the flue comes out the back, I'm planning a 45 bend on there, run the flue out the wall, then another 45 bend to run it vertical outside. (I can't touch the roof of the workshop so it has to be out the wall).

Am I OK running single wall flue through my wall?

I reckon if I cut away all my insulation around there, and cut a much bigger hole than the flue, I can then insulate the space around the flue with something non combustible to stop heat transferring. This would save me having to fork out on twin walled flue hopefully. Any advice on this would be great.

Heat shield: I should be getting my hands on some boards to line the wall behind the stove so no worries there. My workshop walls are chip board. Can I lay boards straight onto that or do I need to leave an air gap between them?

Any fitting advice and where to source stuff would be mighty handy!

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[Dave Budd]

by the time you've made the extra large hole, insulated it with non-combustable stuff and found a cowl that won't burn or leak.... Just buy a short length of twin wall mate, you can get 0.5m to go through if you are feeling poor/tight.

In addition to the not burning your shed down, the insulated flue on the outside will help the chimney to draw better and your burner to work more efficiently/cleanly

 

[Dreadhead]

by the time you've made the extra large hole, insulated it with non-combustable stuff and found a cowl that won't burn or leak.... Just buy a short length of twin wall mate, you can get 0.5m to go through if you are feeling poor/tight.

In addition to the not burning your shed down, the insulated flue on the outside will help the chimney to draw better and your burner to work more efficiently/cleanly

Aye I thought that, but got to gey a connecting collar to go between the single wall up to the twin wall, and don't think it works the other way to go twin wall up to single wall again as nobody is as daft as me, so would have to go twin all the way up which looks like I may have to just bite the bullet and do that but trying to avoid if I can

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[Buckshot]

Is there something strange about the fitting or can you just turn the adapter around to go from twin to single and back?
obviously you would need one at each end of the twin!

we have a wood burner in our conservatory and you can get metal tube a few inches wider than the chimney and cut at 45 degrees. we then just plugged the gap with fireproof rope and put a plate on the outside to seal it. works well.
perhaps you can make something similar from an oil can or similar?

 

[gonzo_the_great]

I have a couple of workshop burners.
One, made from a gas bottle (so similar to yours) I just propped on an old steel wheel rim. That separates it from the ground and lifts it to a more accessible height. Also the holes in the steel rim, allow some airflow.
The other, which is a square domestic one, sits on a slab. And the slab sits on some 3x2 bits of timber. Given the design of the stove, it doesn't do more than warm the slab.

My flues are just single wall galv steel spiral ducting. 5" and 6". They are just cemented through the walls, but my walls are 4" concrete block.
Possibly more work... But how about replacing the workshop wall section, just behind the burner, with brick/block? Put some insulation on the outside and you have a storeage mass, and nolonger need to put fire board around the burner. Then you can take the flue straight through.

Otherwise, as suggested already, just make a collar to go through the wall, with some insulation. So effectivly a homebrew insulated section.
New twin wall stuff is bloody expensive. Possibly see if there are any sections cheap on ebay etc.?

As an aside, I have found that the spiral ducting works for a few years. But the heat/rain rots it after a while. But in my case, I don't mind £20-ish for 5yrs service. It will be interesting to see if the lower temps of the new rocket stove exhaust will last longer. It is cooler, but far wetter. Swings and roundabouts? I'll report back in 5yrs.

Also, with single walled stuff, I am never comfortable lighting it, unless I've first been out to check that the flue is clear of anything combustible that may have falled against it. That may be worth thinking about.

 

[Dreadhead]

Is there something strange about the fitting or can you just turn the adapter around to go from twin to single and back?
obviously you would need one at each end of the twin!

we have a wood burner in our conservatory and you can get metal tube a few inches wider than the chimney and cut at 45 degrees. we then just plugged the gap with fireproof rope and put a plate on the outside to seal it. works well.
perhaps you can make something similar from an oil can or similar?

Because the flues mate in a particular way, it's not possible to just switch the adapter round as the fittings would be the opposite way round.

But your way of making a liner in the ewall is what i'm thinking aye

 

[Dreadhead]

I have a couple of workshop burners.
One, made from a gas bottle (so similar to yours) I just propped on an old steel wheel rim. That separates it from the ground and lifts it to a more accessible height. Also the holes in the steel rim, allow some airflow.
The other, which is a square domestic one, sits on a slab. And the slab sits on some 3x2 bits of timber. Given the design of the stove, it doesn't do more than warm the slab.

My flues are just single wall galv steel spiral ducting. 5" and 6". They are just cemented through the walls, but my walls are 4" concrete block.
Possibly more work... But how about replacing the workshop wall section, just behind the burner, with brick/block? Put some insulation on the outside and you have a storeage mass, and nolonger need to put fire board around the burner. Then you can take the flue straight through.

Otherwise, as suggested already, just make a collar to go through the wall, with some insulation. So effectivly a homebrew insulated section.
New twin wall stuff is bloody expensive. Possibly see if there are any sections cheap on ebay etc.?

As an aside, I have found that the spiral ducting works for a few years. But the heat/rain rots it after a while. But in my case, I don't mind £20-ish for 5yrs service. It will be interesting to see if the lower temps of the new rocket stove exhaust will last longer. It is cooler, but far wetter. Swings and roundabouts? I'll report back in 5yrs.

Also, with single walled stuff, I am never comfortable lighting it, unless I've first been out to check that the flue is clear of anything combustible that may have falled against it. That may be worth thinking about.

Thanks for the reply lots of good information on there. It's the collar idea im thinking of going for as will be simplest for me. putting in new wall would be a bit much for me i reckon

as to the flue outside, my workshop is on a farm with plenty of open space around it so i should be fine on that account but i'll still check it regularly. I have my whole life in my workshop, so last thing i want is an accident with the fire

 

[Dave Budd]

A good reaso to spend on the right stuff then i would say

I got the flue bits for my last set up from here, they were cheapest and have all the bits (also good solid stainless pipes unlike the pipes i got for my other burner) https://www.fluedirect.co.uk/twin-wall-flue-stainless-black.html

 

[Tomteifi]

Hi D.
You need to have or make a steel, 45 degree register plate. Google will show you what they look like but basically; they are two separate

halves of an elliptical shaped plate. When put against each other and slid in or out you will see the shape they can achieve to accommodate your

45 degree up sloped pipe from the back of your fire as it will go through your workshop wall. You could search online for a template to make your

own. The plate itself does not need any insulation as such around it-you just need to cut away enough wood to be clear of heat transfer from the

pipe passing through your wall. Mine is simply pushed together so it almost touches the pipe and is fixed in place with a couple of small bolts and

plenty of heatproof silicone. You should use a short length of single stove pipe from your stove to a point where you can join it to twin wall, which

you should use to the top. You should aim to get the top of your chimney to be at least 4 feet above the apex of your building- helps with draw and

keeping any smoke clear of you or others. The top of mine is 15 feet above ground level and works fine. The hearth underneath the fire is not so

important however, I do not see any legs on your burner so if that's true, you need to get it off the floor by around 4 inches. Some simple steel legs

welded on would be ideal. If your floor is at all uneven, three legs are always better than four.

When you say Heatshield for your walls, are you referring to masterboard, a fire retardant board or something else?

Tom.

 

[demographic]

If its going against a timber wall I would want the heatshield to have an airgap behind it that allows airflow.
Having it tight against the timber means it can transfer heat into the wood and you don't want that.

 

[Dreadhead]

I can't believe it's now November and I still havent fitted my stove. Other things in life have just taken over, but now it's getting cold again the pressure is on.

So I now have all my pipes. (a 90 bend on the back of the stove which will connect to a metre of straight pipe to keep a good deal of flue inside, then a 45 connected to a straight bit to go out the wall, then another 45 to bring it verticle again with enough straight pipe to get it several feet above the workshop). Annoyingly the 45 bend i have fits rather loose onto the stove so it looks like i'll really have to plug the gap with a lot of fire rope.

I also have very good quality thick heat board for behind the stove.

So next weekend i'll build a simple hearth from paving slabs and slate which arent that important as my floor is concrete. it's more to raise it up more comfortably and regs say to have a visible hearth anyway.

I think i need to make a metal plate for both sides of the wall where the pipe comes through? Going to see if i can just buy something with the 45 degree hole in it as that would be easier as i dont have the tools to make one at the moment.

Some advice on my wall/insulation. As my pipe is single wall, I'll get a wider peice of pipe and cut it to fit around and insulate the gap with fire rope and fire cement etc. And the hole it goes through will have to be much larger. So my wall is stuffed with polystyrene insulation. Is it enough to just remove a good section around the hole, or should i rip it out of the entire wall section just incase of heat transfer?

 

[Everything Mac]

I can't believe it's now November and I still havent fitted my stove. Other things in life have just taken over, but now it's getting cold again the pressure is on.

So I now have all my pipes. (a 90 bend on the back of the stove which will connect to a metre of straight pipe to keep a good deal of flue inside, then a 45 connected to a straight bit to go out the wall, then another 45 to bring it verticle again with enough straight pipe to get it several feet above the workshop). Annoyingly the 45 bend i have fits rather loose onto the stove so it looks like i'll really have to plug the gap with a lot of fire rope.

I also have very good quality thick heat board for behind the stove.

So next weekend i'll build a simple hearth from paving slabs and slate which arent that important as my floor is concrete. it's more to raise it up more comfortably and regs say to have a visible hearth anyway.

I think i need to make a metal plate for both sides of the wall where the pipe comes through? Going to see if i can just buy something with the 45 degree hole in it as that would be easier as i dont have the tools to make one at the moment.

Some advice on my wall/insulation. As my pipe is single wall, I'll get a wider peice of pipe and cut it to fit around and insulate the gap with fire rope and fire cement etc. And the hole it goes through will have to be much larger. So my wall is stuffed with polystyrene insulation. Is it enough to just remove a good section around the hole, or should i rip it out of the entire wall section just incase of heat transfer?

I installed my wood stove in the house. Think there was a thread about it on here as I was nervous initially. In hindsight I should have left a much bigger gap between the stove and the walls. But everything I’d read suggested it was fine but never mind. Haven’t had any issues as yet.


Not sure what boards you’ve got but cement board is an acceptable non flammable barrier. And it’s about £6 in b&q for a sheet.

Ideally you want as much space between the pipe and anything flammable as you can practically get away with. I forget the minimum distance now. 12” comes to mind, but you’d have to check.
where it goes through the wall I’d use a double layer of the cement board, cut at a suitable angle to allow it to pass through. You can work the stuff with normal hand tools.

If you fill a gap between the pieces use something like ceramic fibre blanket ideally but a fire blanket would do.


With regards to the loose fitting pipe, that’s not ideal. How loose is it? Is it loose both sides of the connection? if so it might be best to save up for the right size fitting. They can be had on eBay relatively cheap. Cheaper than a stove shop for sure.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/112588737144

All the best
Andy

 

[Dreadhead]

cheers Andy.

Got a nice solid hearth built in now. And I came across a guy selling brand new twin wall pipe dirt cheap so i've gone and bought that to make life easier and safer. The fire boards i have are expensive good quality ones a friend kindly gave me as he had a surplus left over. I plan on cutting a strip off it and making washers from it. I'll fix it to the wall with a 20mm air gap using washers from the same material. And behind my chipboard wall there is actually a 20mm air gap between the wall and my insulation too so im hoping that's all pretty safe. when i cut the hole for the flue though, i'll dig out as much insulation as i can around the whole and still fill it with something, even with the twin wall flue passing through. I read it's recommended to still use a wall sleeve even with the twin wall flue so i'll pick one of those up too i guess. taking no chances!

Aye flue distance from the wall is a pain, because the pipe join comes out the back of my stove at 90, so i've got a 90 bend on there to bring it vertical, but it still sticks out the back a fair bit so my stove has to be quite far in front of the wall. my hearth is almost a metre square, so plenty of room behind the stove im sure.