stove cooking roof

[glider pilot]

I have just bought a canal boat with a squirrel stove fitted

If the stove has wood burnt in it the roof gets really hot and an acrid smell comes under the roof linings and into the cabin 

it is not a smoke smell but more a melting plastic smell

 

any ideas of reason before  I start tearing the ceiling down 

 

many thanks

Neil

 

 

[Bee]

Dunno but I would investigate pretty quick. Could be badly routed wiring, could be all sorts of stuff but something is too hot and close to going up in flames.

[Tony Brooks]

A photo of where the flue goes through the ceiling may help see how char proof the ceiling is. The smell could be the glue used in plywood or any composite board. It could also be products of combustion leaking into the void between ceiling and roof. maybe your boat has expanded polystyrene insulation that is melting.

[tree monkey]

39 minutes ago, glider pilot said:

I have just bought a canal boat with a squirrel stove fitted

If the stove has wood burnt in it the roof gets really hot and an acrid smell comes under the roof linings and into the cabin 

it is not a smoke smell but more a melting plastic smell

 

any ideas of reason before  I start tearing the ceiling down 

 

many thanks

Neil

 

 

What the others are saying is really important but I am curious about how hot it's getting, are you unable to control the rate of burn, squirrels are very very controllable unless they have some problem, poor seal maybe, it really shouldn't matter what you burn you should be able to control it

[Ianws]

Is there a gap between the flue and the regular roof lining and what’s filling it? 

[glider pilot]

thanks all

will get photos tomorrow

its defiantly not smoke so flue isn't leaking 

I suspect there is an air gap after the flue enters the roof section and the outer skin of the boat 

 

 

 

[Tony Brooks]

3 minutes ago, glider pilot said:

thanks all

will get photos tomorrow

its defiantly not smoke so flue isn't leaking 

I suspect there is an air gap after the flue enters the roof section and the outer skin of the boat 

 

There usually is but it is often full of thermal insulation.

 

How do you know its not fumes?  Have you had the roof or flue trim down to look? flues are known to rust through at the base of the flue collar. It could be tar that has not leaked down the outside of the flue yet. make sure the ceiling wood is at least 1" away from the flue and any thermal insulation in that area is incombustible like Rockwool

[Tracy D'arth]

Is there a cast iron collar on the roof where the flue pipe terminates?  There should be, or at least a welded in flange. 

[bizzard]

Has it a GRP top ?

[glider pilot]

yes cast Iron top 

 

[Tony Brooks]

6 minutes ago, glider pilot said:

yes cast Iron top 

 

I think Bizzard was talking about the boat roof, not the stove top.  There is much we don't know about your boat. it could have a steel, a GRP, or a wooden cabin top. All could react to heat in different ways. Most of us assumed that you have a steel roof and a cast iron roof collar but it may well not have. its the same with the possible roof insulation etc.

[glider pilot]

yes steel roof with cast iron collar

 

[ditchcrawler]

1 minute ago, glider pilot said:

yes steel roof with cast iron collar

 

And do you have any type of trim ring round the flue attached to the ceiling? 

[glider pilot]

yes a brass one

 

[ditchcrawler]

Just now, glider pilot said:

yes a brass one

 

And can you drop it to see what is above it against the flue above the ceiling?

[glider pilot]

pictures attached

[Tony Brooks]

The second photo seems to show the cast iron roof collar is nearly flush with the underside of the ceiling and I can not identify any thermal insulation in the roof void.

 

I cant see any signs of packing rope or sealer between the flue and collar so it might be a failed seal at the top of the collar allowing fumes into the roof void. It might also be thermal insulation too close to the flue collar, especially if it turns out to be polystyrene.

 

It looks like a weld or casting line in the flue about level with the bottom of the collar, what is this?

 

Any chance of a photo of the top of the collar without the chimney in place so we can assess the seal between flue and collar.

[glider pilot]

i did not install this so if there is something missing please don't be shy on pointing it out 

will take picture tomorrow of the top

many thanks for help

 

yes it is polystyrene

 

Neil

Edited December 8, 2020 by glider pilot

[Tony Brooks]

9 minutes ago, glider pilot said:

i did not install this so if there is something missing please don't be shy on pointing it out 

will take picture tomorrow of the top

many thanks for help

 

yes it is polystyrene

 

Neil

How large is the air gap between the insulation and the roof collar?  Seeing how close the collar is to the ceiling board \i fear it may be all but touching. I cleared all mine away for six inches all round the flue and collar and replaced it with Rockwool.

[glider pilot]

did you have the same problem?

 

 

[Tony Brooks]

10 hours ago, glider pilot said:

did you have the same problem?

 

 

No, I was fitting the stove as a new appliance. If you have ever seen a stove run away, especially not long after fuelling, you would be far more careful about the distance between all potentially hot surfaces and combustible material. A stove and bottom of flue roaring and glowing red hot is impressive and in a wooden structure scary. Where you have a metal ceiling trim disk I have a 12" plus rectangle of fire board painted black. Tha was to give access to change the insulation as well as ensuring it can't catch fire.

[ditchcrawler]

2 hours ago, Tony Brooks said:

 . Where you have a metal ceiling trim disk I have a 12" plus rectangle of fire board painted black. Tha was to give access to change the insulation as well as ensuring it can't catch fire.

That is how I did mine and its only a little back cabin stove, yes I have seen the flames roaring out of a chimney like a big blowlamp.

[David Mack]

2 hours ago, ditchcrawler said:

That is how I did mine and its only a little back cabin stove, yes I have seen the flames roaring out of a chimney like a big blowlamp.

Many many years ago, I had no chimney, and it was very cold, so I improvised with a sheet of corrugated cardboard rolled around the chimney collar, reckoning it would never get that hot so far above the stove.

I was wrong!