Woodburner

[Gunner]

Please help.

We have put a woodburner in our small converted barn that goes through the lounge ceiling and up through the bedroom and out through the roof. To miss the central beam upstairs we have had to put two 90° bends in with a 60 cm straight piece in between. As we were trying to find 72° bends to use instead of the 90° ones I have not sealed the sections so as I can take it apart again. Not sure if I was being a bit dim in thinking that as smoke rises then I shouldn't have a problem ?.

Anyway the problem is that we have dirty coloured water (condensation ?) leaking out from the top joint of the flue where it runs down the 90° bend and drips off into a bucket (as you can imagine my wife is not to keen on this smelly bedroom accessory). The joint is about 80cm down from the roof. 

What I need to know is if I seal the joints so I don't have a leak is it going to be a problem later on with this black slightly sticky water running down the inside of the flue.

[Gp]

Hi

You should replace the 90 degree bends with 45 degree bends, installing with sockets uppermost to prevent any condensation from leaking out.

 

Graham

[Gunner]

Thanks for your prompt reply Graham. Not too sure what you mean about 'installing with sockets uppermost'? Could you maybe clarify? We wanted 45° angles initially however Bricomarche did not stock them. Unfortunately we bought all of the other flue from them in black and no other store seems to stock the same colour, hence buying the 90° angles. I thought that this was probably the problem though.

[bigjimbishop]

I had exactly the same problem and solved it by fitting the pipes the other way round. This means cutting a small section to fit on the back of the stove so the "plug" end of the pipes point towards the stove and the "socket" ends towards the roof.

Also if the whole length of pipe is uninsulated right up to the tiles then it may be cooling too much hence the condensation of resin (dirty brown fluid) you experienced. The cheapest way I found to insulate the pipe where it goes through my attic was with Laine de Roche (aluminium backed rock wool).

The resin is nasty stuff if it gets to a hot bit of pipe and will make you ill!

Bon Chance

[Gunner]

Good advice fitting the pipes the other way round, however it is a bit worrying thinking of all the resin staying on the inside of the pipe and maybe clogging it up. The problem we have with insulation is that the pipe runs straight through the middle of our bedroom and out through the roof so we cannot put anything around it. I think perhaps the wood we are using is not that great either.

[Gp]

Hi

The female end (socket) of the bend/pipe should face upwards - this prevents any condensation leaking from the joint.

Graham

[Deimos]

I believe there are strict regulations about chimneys and flues inside the house. I don’t know if chimney flue and boiler flues are different and I am no expert but I had an architect round to look at an attic conversion I am considering and he saw a flue running up the corner of what would be one room and he told me that I must box it in airtight so it is not in the room. He was also going on about minimum gaps between the flue pipe and the floor boards, etc.

Again I am no expert but be careful about the regulations, not only for your safety but also that if you had a fire or anything, then your insurance may easily try to blame it of your installation and declare you not covered.

You may be a professional and fully aware of all this, in which case my apologies.

Ian

[Gunner]

No worries, Ian. Professionals we are not, so will bear your comments in mind! Perhaps someone else may know the answer to this?

[bobwils]

We had the same tar residue problem with our log burner for the first year then, it stopped and has not re-appeared. The only thing I could think of was that a 'coating' had built up on the flue-pipes which stopped the condensation. Also we turned the piping around as the other respondant suggested and this stopped the leaks.

 

Bob Wilson

[LesFlamands]

To comply with regulations you must use double skinned flue where the chimney passes through the roof and where it passes through any intermediate floors. You would be much better off using double skinned pipe for the entire installation as this will prevent the condensation forming in the first place.

[Ernie]

Thanks for the tip, Charles. Our Villager stoves supplier and fitter, fitted the flue the wrong way up and condensation poured out of it. Pity you weren't there, to have told him that this double skin jobby would have done the trick. We must tell him, when he comes back to re-fit it properly. I'm assuming he at least did the double-skin when it went through the roof. Any way of checking?

 

Best

Ernie

[Tag]

Are we talking about simple wood burners or inserts on this thread? The former seem to work almost anywhere whilst the latter are a positive menace unless installed properly