Wood burning stove flue liners

[joe90]

Without opening a can of worms on the merits of wood burning stoves and pollution, like a few of you on here, we are having a small, efficient wood burning stove ( room sealed ) but have the following question. Our builder was going to use concrete liners in a brick and block chimney but I see that pumice or clay liners are more expensive and so I presume more "efficient". My question is if the liner is insulated with Leica within the brick/block build is the extra expense of pumice or clay worth it?. 

[PeterW]

I've gone for Dunbrik ones - decent calculator on price on their website too

[Temp]

Are you talking about putting an SS liner inside concrete? I'm sure I read somewhere that SS liners are not allowed on new builds? or perhaps it was "not recommended" rather than not allowed?

 

 

Edited December 20, 2016 by Temp

[Temp]

Ah this is what I was thinking of....

 

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/468872/ADJ_LOCKED.pdf

 

Use of flexible metal flue liners for the relining of chimneys

1.40 A way of relining a chimney would be to use an independently certified flexible metal flue liner, specifically made to suit the types of fuels to be burnt. Flexible flue liners should only be used to reline a chimney and should not be used as the primary liner of a new chimney. They can be used to connect gas back boilers to chimneys where the appliance is located in a fireplace recess.

 

 

[joe90]

Yes mate, I had read this. The Dunbrick site is great Peter, a good place to start. But I would still like to know if clay or pumice is worth the extra expense?

[CC45]

Ours is clay pipe & insulation between it and the chimney. Draws well.  We held it all up with lintels & blocks but a far better idea is to cast the bottom slab with the pipe in it & use B&B set up to 'roof' of the fire place.  Not got a pic unfortunately..

[ProDave]

10 minutes ago, CC45 said:

Ours is clay pipe & insulation between it and the chimney. Draws well.  We held it all up with lintels & blocks but a far better idea is to cast the bottom slab with the pipe in it & use B&B set up to 'roof' of the fire place.  Not got a pic unfortunately..

We have the same flue liners.

 

I remember the bricklayer fiddling around a bit with some lintels to try and support the flue liners. Then he said "nah, that's not going to work" He then went outside and came back with one of those really thick 600 by 900 paving slabs. Cut a hole in it to match the flue liner, and put that on as a "roof" to the fireplace and for the flue liners to sit on.
 

[Declan52]

http://www.hughesprecast.co.uk/Building/Flue-Gathering

Always used something like this to start. Gets built in and the liner then sits in the groove. Gets back filled with a vermiculite mix as you build it up. 

[joe90]

Thanks guys, is there any statistics that show clay or pumice is worth the expense?

[Temp]

It's an interesting question. You want an insulated chimney so it runs hot and draws well but on the other hand that means you get less heat leaked into the rooms upstairs and more lost up the chimney.  Our chimney used pumice but does seem to leak a lot of heat into the room upstairs.

[joe90]

1 hour ago, Temp said:

It's an interesting question. You want an insulated chimney so it runs hot and draws well but on the other hand that means you get less heat leaked into the rooms upstairs and more lost up the chimney.  Our chimney used pumice but does seem to leak a lot of heat into the room upstairs.

Hi Temp, did you have pumice liner and insulation , then did you have concrete/brick around that? I can see that a pumice liner would not suck heat out of the gasses so much and so presumably the fire would draw faster. We are only having a small stove and not have it lit for extended periods so wonder if it's not worth the expense ( double that of concrete liners).

[Temp]

To be honest I wasn't there when the chimney went up. I think we have round pumice liners, insulation and blocks. However the insulation can't be very thick due to the overall dimensions.