Flue liner and installation

[Barbel Bob]

Hi all,

I have decided due to the problem i had with 'no draw' (earlier post) in my chimney to go ahead and buy a log burner, to reduce the costs we have decided to install the burner ourselves, so will need your help with some questions please [8-)]

I am fitting the log burner into the fireplace, I have read in several places that a lot of heat will be lost up the chimney, and I wonder if any of you have done the same and regretted it.......we plan on using a register plate with rockwool above.

We were thinking of buying flexible flue liner, though as our chimney is quite straight would a straight one be better? easier to fit etc?

We were going to insulate the flue liner, and noticed on a uk website that they sell insulation jackets, the only thing i can see here is 'vermiculite' at brico depot? another site suggests wrapping it in rockwool and securing with wire, is this more trouble than its worth, and what is the french equivalent for rockwool, and has anyone any idea were to buy the insulation jackets?

Thanks

J

 

[HoneySuckleDreams]

i wouldn't use rockwool. Capping of the chimney you have to use "Pink" plaster board (unless you want to go the steel route). This is the stuff that is fire retardent. (it's a bit heavier and a bit more expensive). The insulation above the capping has to be special stuff as well. I wouldn't bother insulating the flue. Although you can buy double lined insulated tube for the flue. Flexible is OK as I bet your chimney is not perfectly vertical, there's normally a kink in it which is a pain. (but you can buy stainless steel mutli joint thingy to get round that problem). Flexible is OK, but supporting it at the top is a pig, especially if your chimney is very old and 10' high!

[Jacqui Too]

Hi Bob/Julie

Wood burning stove is your best bet to solve your lack of draw.

What you need is a flexi liner with a special collar to attach to the top of the chimney, you need to fire proof and seal off the chimney about 1- 1.5m above the burner, this must be strong enough to hold up the flue and the filler, (not just fire resistant plasterboard its not strong enough) we use either a concrete shuttered slab or a steel plate.

Pull the liner up from the bottom with the use of a rope and secure with the securing collar, back fill all the chimney with vermiculite(sp) then all you need to do is finish of the top of the chimney with a pot or as you are in France one of those fancy little tile things.

Dont use any thing other than vemiculite, its perfect for the job.

Good luck

[clarksinfrance]

While vermiculite is the right product for the job, think on to the future, flexi liners are designed to last 10 years, that said, depending on type and quality and humidity of the wood, the condensates are very corrosive, so liner may need replacing in as little as 5 years, it may also last 15 years. Areyou going to still be living in that property when/if it becomes necessary to change the liner? If yes, what will you do with dozens of bags worth of loose vermiculite when it comes cascading down the chimney, as you remove the old liner? Can you postthe web-address of the company with an insulating jacket? Flue has to be supported top and bottom, exit from chimney should be at least 60 cms above ridge line (though it isn't always possible, so other distances from neighbours/rooves etc are recommended). Does your burner evacuate from the back or top? If from behind, the horizontal run should not be more than 150mm. You need solid tube to sit between fire and flexi-liner, IIRC at least 40cm. Need permanent airsupply to room, amount depends on fire rating. Hearth has to be certain size.

If you have to use bends, no more than 2 and both 45degrees or less. NEVER REDUCE DIAMETER OF FLUE FROM FIRE EXIT.  Fire needs to be sat on a suitable heatsink. Need an installation plate describing the type of installation. Plus a myriad or other rules and regs.

If you have plenty of space around your woodburner, may I suggest 2 things, firstly don't store logs there, as the side of a burner can quite easily reach 500degrees, and set light to the stored logs (personal experience), and secondly we have used high density foil-backed insulation to line the old fireplace, that allows nearly all the heat to be refected back into the room, instead of heating up the immediate wall area around the fire, which can be 1m or so thick.

Have a doc on our website, which shows distances of combustible materials from flue:

http://www.gite-maintenance.co.uk/Home/UsefulDocuments/tabid/96/Default.aspx

Hope it helps

Nick

[jondeau]

Excellent stuff Vermiculite.........however so fine and light are the granules that they flow almost as well as water, any tiny little gaps around your register plate and it will trickle out all over the place.

For the initial few buckets of fill it is worth mixing it with cement and water (Vermiculite Concrete...as it is known) this will provide a solid base and good seal around the flue and over the register plate.

[BIG MAC]

As for controlled removal the vermiculite will compact in time in any case but all you do is push the liner up above the register plate and slightly to one side having created a hardboard chute. into a  1 tonne jumbo bag (Hippo bag for those who don't get bulk deliveries) by moving liner back and forth above register plate the flow of vermiculite can be controlled and mess minimised.

Take tonne bag outside (Vermiculite is very light although this may be slighlty heavier than normal as some moisture will likely be present) and bag up into smaller bags ready to go again.

I would suggest using paper overalls a nuisance dust mask and eye protection just in case.

 

[HoneySuckleDreams]

Make sure you know what your doing.

No 1 son got us out of bed this morning (he leaves at 6:45 for school on wednesdays) and pointed to our neighbours chimney which had 4 ft flames coming out of the top. "Is that a problem" he asked.... only a 14yr old can make that sort of understatement