200mm/ 8" Roof Collar Morso Squirrel Instalation

[mooter]

Can anyone advise,

 

I am busy sourcing the parts to instal a 6" twin wall flu onto a Morso Squirrel stove, the twin wall flu is 200mm external diameter has anyone any experience in sourcing a roof collar to accommodate the 200mm external diameter flu pipe? I have seen a twin wall kit but the roof collar seemed flimsey and I was hoping to find something quite chunky can anyone help. In advance many thanks!

Edited May 27, 2015 by mooter

[blackrose]

If you want a proper cast iron flue collar of that size you might need to have one made. Most people on boats only use twin wall chimneys - the flues inside the boat are normally single wall. If you want twin wall thoughout it starts to create these issues.

Edited May 28, 2015 by blackrose

[pophops]

Surely much of the efficiency of a multi-fuel stove comes from the considerable amount of heat radiated from a single-walled flue. With a double-walled flue, won't you just be piping much of this energy straight out of the boat?

[mooter]

Thanks for your comments, I believe that a new build installation requires a double skinned flu to be installed without a flu joint in the roof space, I think you are right regarding the heat radiated from a single wall flu but rules is rules if you want a safety cert. Does anyone have any experience with this sort of installation under the new rules using a double skinned flu through the roof?

[westweala]

you get a "lead slate" its actually tin or ally with the cut to size rubber seal and sticky bitumin mastic sealant around the edge.goes on the same as it would a dwelling, simples. about £30ish off ebay.its what ive got for my 200mm flue.ttrust me, im a roofer:-)

[pophops]

Thanks for your comments, I believe that a new build installation requires a double skinned flu to be installed without a flu joint in the roof space, I think you are right regarding the heat radiated from a single wall flu but rules is rules if you want a safety cert. Does anyone have any experience with this sort of installation under the new rules using a double skinned flu through the roof?

Fairy nuff

[westweala]

and if you want to make it look nice on the inside, use a 9" brass porthole as a collar, again about £30ish off fleabay.looks great against the stainless twin wall flue :-)

[mooter]

That's great, thanks for the info ...... sorted

[onionbargee]

My Squirrel flue is single skin 1 mm stainless, it belts out a ton of heat as soon as i light the fire, I only put it in as a temporary one, but I'm convinced its the best flue I've ever had, im not going back to thick wall steel tube.

 

What is the purpose of an insulated flue on a short run of 1500 mm or less ?

 

How much heat are you going to waste with an insulated flue ?

 

And why do you think you need one ?

[mooter]

I agree with everything that you state, however the new build regs for the safety certificate expect twin wall insulated with no joint in the roof void, so I am assuming that I would need to follow these instructions to achieve a safety cert, as I said earlier rules is rules!

[Neil Smith]

I agree with everything that you state, however the new build regs for the safety certificate expect twin wall insulated with no joint in the roof void, so I am assuming that I would need to follow these instructions to achieve a safety cert, as I said earlier rules is rules!

I cant find anything in the bss guide that says you need double skinned flue pipe, or are you building to rcd regs to sell on within 5 years?

 

Neil

[blackrose]

My Squirrel flue is single skin 1 mm stainless, it belts out a ton of heat as soon as i light the fire, I only put it in as a temporary one, but I'm convinced its the best flue I've ever had, im not going back to thick wall steel tube.

 

What is the purpose of an insulated flue on a short run of 1500 mm or less ?

 

How much heat are you going to waste with an insulated flue ?

 

And why do you think you need one ?

How long will a 1mm wall thickness flue last? Stainless chimneys of similar thicknesses don't seem to last very long in my experience. Personally I'd want something a bit thicker.

Edited June 2, 2015 by blackrose

[bizzard]

The thin stainless flue will not last long unless vigorous sweeping is avoided. Let a skin of hard, dead sooty clag build up in it, this will help prevent the acids and corrosive chemicals in the fuel from attacking the metal. Then sweep lightly in future trying to leave a thinnish layer of clag behind. It should last a good few years then.

[rjasmith]

I agree with everything that you state, however the new build regs for the safety certificate expect twin wall insulated with no joint in the roof void, so I am assuming that I would need to follow these instructions to achieve a safety cert, as I said earlier rules is rules!

 

Where did you get this from? It is not correct!

 

The BSS does of course recommend that new installations take account of the British Standard Code of Practice BS 8511 but even this is not mandatory. BS 8511 recommends a twin wall flue but even in there it is OK to have the lower section of flue in single wall if you prefer.

 

The BSS uses other criteria for pass/fail of the BSC in respect of a stove installation but full compliance with BS 8511 (NB this is not a BSS document) is not a requirement.

 

It is also (surprisingly perhaps) not a requirement of the RCD either. The RCD has never "heard" of BS 8511 and has its own Fire Protection Standard which is ISO 9094. That does not mention a twin wall flue either!!

 

The Morso flue system seems to be based on household style components (eg Selkirk flue or similar) and my worry about these would be how well the external bits stand up to the rough treatment they are going to get on a canal boat.

 

There are very few suppliers of "proper" boat friendly flue systems IMHO that comply with BS 8511. One is made by a little outfit called Warstock Developments but it sounds like you've already gone for the Morso set up.

 

Richard

[mooter]

Thanks for your replies, the information was sourced from the Boat Safety Scheme web site which directs you to the following link, http://www.soliftec.com/installation.htm I haven't decided on any system as yet but I do have a Morso stove ready to go. I am merely asking the question of those that will have much more experience than myself. I take the points fully regarding single skinned installations and actually have one installed on a sea boat that we are selling, but when we install the Squirrel I want to make sure that I tick all the boxes just in case.

[rjasmith]

Thanks for your replies, the information was sourced from the Boat Safety Scheme web site which directs you to the following link, http://www.soliftec.com/installation.htm I haven't decided on any system as yet but I do have a Morso stove ready to go. I am merely asking the question of those that will have much more experience than myself. I take the points fully regarding single skinned installations and actually have one installed on a sea boat that we are selling, but when we install the Squirrel I want to make sure that I tick all the boxes just in case.

 

The Soliftec sketch is a precis of BS 8511 and therefore gives a subset of 8511's recommendations ie not all the possible arrangements that 8511 recommends. You have to read the full doc to see which would work best for you, assuming you feel you want to work to it, as recommended, not required by BSS.

 

Unfortunately getting to read BS 8511, as with any standard published by British Stds is not straightforward. You could buy a copy or borrow one if you know some organisation that will lend it. The way I do it is to join Manchester City Library. It's free and anyone in UK can join (I live in Sussex!) Once you've joined (simple online procedure), MCL allow you to link to British Stds Online (BSOL) via their website for free and then you can read almost any BS or ISO (you can't download or print them). Very few libraries now do this because of the costs and rules imposed on them by BSOL.

 

Richard

[Neil Smith]

I am just doing a new build to bss and I am using a 4mm thick wall steel pipe for the flue from stove to collar in one length then a twin wall chimney, the single wall flue should get nice and hot to radiate heat that would be lost on twin wall, the bss inspector I met at crick said it will pass ok and should last years and the bonus it was an of cut so only cost me a drink.

 

Neil.

[mooter]

Forum members have been more than helpful, thanks for all your responses. Obviously there is a little leeway in the installation options in order to meet the requirements. I will study the relevant docs and make a decision, I certainly would prefer the cheaper option. Many thanks.

[canals are us?]

Rather than a lead slate for the collar I would cut a circle out in the roof steelwork a bit bigger than the twin wall and have welded into place a 3 inch steel upstand rolled into the circle. This would look neater and be leak free.

The twin wall flue from stove to just above upstand height, then storm collar to weatherproof joint from upstand to flue. Then another twinwall length joined above upstand and storm collar to use as the chimney above the boat. You could have a short piece for just cruising and longer when stationary. This would enable you to make it from standard household parts.

 

James