Putting a flue through a timber shingle roof

[mikeyt1968]

This season I will be putting a timber framed roof over my oven with a cedar shingle top.

Does anyone have any experience of using a 6 inch single wall vitreous with a wooden roof structure?

I have all the timber for the frame from various building jobs, and apart from buying the cedar shingles want to keep the costs low. My oven flue is removeable and my initial plan is just to leave a hole on the ridge, probably square with a couple of inches of air gap around the flue with some sort of cover over the hole when the oven is not in use.
The main reason for the roof is to stop water ingress into the oven when not in use, the wet winter has not been kind and the oven will need a lot of drying out before use this year!
Any advice or thoughts welcome

Mike

[burntcrust]

Hi Mike,

You might want to consider a cast iron collar-we used them on our narrow boats for passing the flue from coal stoves through the wooden roof. Can be found in most canal side chandlers.

Good luck,

Burntcrust

[mikeyt1968]

Hi there

Sounds interesting, Is there an online canalboat chandlers?

[burntcrust]

Mike,

Try www.midlandchandlers.co.uk and search for roof collars, have various diameters 4.5"/5"/6" all around the 40-50 quid mark.

Best,

Burntcrust

[mikeyt1968]

Thanks. Will have a look

[cannyfradock]

Mike

As much as I admire roofs with cedar shingle (seen them in France on "Pigeoniers" and windmill conversions)...I have no first hand knowledge of these....along with suggestions from burnt crust. The only input I can give is to make sure that when you set your wall plate and roof truss/ridge board ...you leave enough room for at least 3" of loose vermiculite to protect the timber. The crucial part will be chimney area. ??

Terry

[mikeyt1968]

Thanks Terry

The plan is to just just build the roof on four 4x4 posts that sit on each corner of the plinth the dome is sat on, a bit like a dutch barn just so the roof protects the dome from the elements so their should be no heat transfer issues as the dome is well insulated and is cool to the touch even when running at full temp, its just the flue through the roof that will be a challenge.
I will post some pics when underway.

Mike

[mikeyt1968]

Had a free afternoon and managed to get started on the roof (in between showers)

The four uprights were a 4 inch square fence post and the rest of the timbers are 4x2, the plan is to finish the trusses and then clad with cheap 6 inch treated gravel boards and then a cedar shingle finish.
The battens on the front are just stopping the front from spreading and not permanent! I am going to tie the front together with a custom made square section wrought iron tie fixed at each end to the timbers. I have chosen iron as the area above the entrance is subject to a bit of heat escaping and won't hide too much of the brick arch.
I may also add some hangers on the tie for peels etc, but will see how much the blacksmith charges and also how the tools will sit.
The interesting bit will be the flue (not shown in picture) that will have to go through the roof.
Will post the next stage when time, work, family, money and weather prevail.

Mike

[mikeyt1968]

After a productive Good Friday the roof is on.

Already having a removable flue the plan was to put the flue through the roof when needed and then cap the ridge when not in use. In the end I used some scrap stainless steel mesh to keep the hot flue from touching the timber roof and then some scrap aluminium sheet with a cedar ridge as a cap when not in use. I also got a local blacksmith to make up a steel square twist tie to stop the front of the roof from spreading.

All in all I was very pleased with the results.
Mike

[blackcat]

I have an oak pergola with shingle tile I’ve bought a wood burning hot tub and need to put single flu through roof but to make sure it does catch fire need a solution to how to do anyone done before ? Also how do I add pictures to show you all ?

[redwood]

Jun 21, 2018 14:59:30 GMT blackcat said:

I have an oak pergola with shingle tile I’ve bought a wood burning hot tub and need to put single flu through roof but to make sure it does catch fire need a solution to how to do anyone done before ? Also how do I add pictures to show you all ?

Hi blackcat I have a similar issue, how did you resolve please? I have a european 5.5 inch flue single but ideally needs to be a double skin to absprb the heat. I have spoken to a couple of companies that suggested to put an adapter on and then buy a 6inch double skin. Ideally I need a high temp waterproof shroud, as the ones I have seen only go up to 200 degrees.

Any ideas?

Thank you

[devontiger]

Guys, I did this with my oven.
I built a gazebo with polycarb sheets.
I then made a square batten frame the size of the chimney collar, from ebay.
Screwed this to the polycarb & place a twin wall chimney through that.
The twin wall doesn't get that hot so the heat proof collar is well ok.

You will find the single wall chimney gets very hot. Too hot really, so if pos use twin wall, you only need a meter, max.

[Thomobigands]

Just to be a killjoy, check you are not in a smokeless zone as passing the flue through a roof tips it from a BBQ to being governed by DEFRA I think. That's what my local Council told me a few years ago anyway.

[redwood]

Sept 5, 2018 10:07:23 GMT devontiger said:

Guys, I did this with my oven.
I built a gazebo with polycarb sheets.
I then made a square batten frame the size of the chimney collar, from ebay.
Screwed this to the polycarb & place a twin wall chimney through that.
The twin wall doesn't get that hot so the heat proof collar is well ok.

You will find the single wall chimney gets very hot. Too hot really, so if pos use twin wall, you only need a meter, max.

I have a single wall 140mm flue at the mo so struggling for a resolution, any ideas? please

[devontiger]

I would suggest you take the Temp of the chimney when alight & then check to see what Temp the chimney collar will take.
The Red one, as in the photo is the hottest one they do.