Neighbours gas fire flowing through flue in my property!

[Humdinger1970]

Hi all, complete and utter layman here trying to get some advice. Apologies for the length of post!

I live in a semi-detached dormer-roof house. There are two pre-cast flues along the ridge tiles of the roof, one on my side, one on my neighbours.

I have an electric fire and my neighbours have a gas fire on the other side of the wall. They have recently had a new fire fitted. My neighbour knocked on the door and advised that when his fitter was putting the new fire in and testing the flue, they discovered that their fire was venting through the flue in my wall and coming out of the vent on my side of the roof. He suggested that when the property was built (early to mid 1970's) it must have been that "somehow" the two flues were crossed over?

My neighbour asked was it alright if the fitter went up onto my side of the roof to check the vent, to which I said fine. Week or so later, neighbour called again and said because of this crossover flue issue, the fitter wanted to go into my loft to check that there was no issue re leaks etc. As far as I know, there are just breeze blocks separating the two loft spaces.

Noticed this evening that our living room wall and the bedroom wall directly above is getting very warm to the touch vertically along where the flue will be.

Need to call this fitter tomorrow about going in the loft but am now getting a bit worried that things are not right. Questions are:

1) Is it possible that these flues could have been "crossed over" when the property was built? If not, how else could the neighbours fire be venting through my flue?
2) Is it normal for a wall to be so warm to the touch along the vertical line of the flue?
3) On the one hand, happy for the fitter to go into the loft to check things out but is it more advisable to get our own engineer in too to check things over? Obvious safety concerns but whose responsibility is it if there was a problem with my flue caused by my neighbours vented gas, bearing in mind my fire's electric and so my flue should really be redundant? Could my buildings insurance be affected in any way?

Thanks for reading and any advice.

 

[Agile]

As an engineer it means little to me that you say it is warm as I have no idea what temperature that is.

The first thing to do in a case like this is for the gas fitter to put a smoke pellet into your fireplace and into the neighbour's to see which chimney the smoke comes out of.

Its quite common for flues to be joind together further up! Presumably as a builder's bodge or mistake?

Tony

 

[Humdinger1970]

Thanks Tony - do appreciate warm is not a particularly technical term!

Effectively believe that's what fitter did next door, but if there has been a bodge with the flue, must be very low down for the wall to be getting hot where it is!

 

[Agile]

He needs to do that test to ensure the safety of you and your neighbour's fires!

 

[mickyg]

it sounds very very wrong. If I looked at a fire and smoke came out of a terminal on a neighbouring property, it would get chopped off instantly. It sounds more likely the 2 flues are compromised somewhere which would be classed as a dangerous situation. I'd recommend getting someone else in yourself.

 

[sherbert]

As an engineer it means little to me that you say it is warm as I have no idea what temperature that is.

The first thing to do in a case like this is for the gas fitter to put a smoke pellet into your fireplace and into the neighbour's to see which chimney the smoke comes out of.

Its quite common for flues to be joind together further up! Presumably as a builder's bodge or mistake?

Tony

Tony

Please tell me how many times youve seen flues joined together ....... Have yet to see one in 30 years ...... totally fail to see how they can be joined together?? Have seen a few were the pug has gone between some bricks mean that flue gases can move across the individual flues ...
having spent a large part of the mid 80s fitting back boilers and copex liners never found the liner going down the wrong chimney .... So .. how many if its quite common??

 

[Agile]

Tony

Please tell me how many times youve seen flues joined together ....... Have yet to see one in 30 years ...... totally fail to see how they can be joined together?? Have seen a few were the pug has gone between some bricks mean that flue gases can move across the individual flues ...
having spent a large part of the mid 80s fitting back boilers and copex liners never found the liner going down the wrong chimney .... So .. how many if its quite common??

Thats what I mean by joined together!

Since I rarely encounter gas fires and only a very few back boilers now, I dont expect to see that problem myself and have to rely on others like you who were installing loads of them in the 70/80s.

Tony

 

[sherbert]

Tony

Please tell me how many times youve seen flues joined together ....... Have yet to see one in 30 years ...... totally fail to see how they can be joined together?? Have seen a few were the pug has gone between some bricks mean that flue gases can move across the individual flues ...
having spent a large part of the mid 80s fitting back boilers and copex liners never found the liner going down the wrong chimney .... So .. how many if its quite common??

Thats what I mean by joined together!

Since I rarely encounter gas fires and only a very few back boilers now, I dont expect to see that problem myself and have to rely on others like you who were installing loads of them in the 70/80s.

Tony

Be very careful what you write then .............. Joined together at the top and builders bodge are implying that they are joined togehter at the top due to a incompetent builder
Not due to the fact that some of the pug has gone between the bricks due to an old chimney and the effect that soot can have on mortar
The guy that asked the original question ...... ask that they put smoke bomb up each chimney but they may need to go up on the chimney when they do this as sometimes it will only be a very small amount that moves across if the chimneys integrity has been compromised
I think that your case maybe that the two chimneys lay side by side rather than back to back so you can feel the heat from the fire although it would have to have been running for a long time for you to feel any heat through the brick work
How old is the house by the way

 

[Humdinger1970]

Thanks for comments.

Sherbet - house built about 1973/4.

Complete layman as I say, so chimneys/soot makes me think of real fires(!), not gas. As mentioned, neighbour's fitter did establish ( I am assuming with a smoke test) that fumes going through the vent tile on my side of the roof.

Should each of our respective flues be in or own brickwork or would both flues be in the cavity gap between he two walls? Feeling hot air must be going through flue in my brickwork as it's feeling so warm all the way up on the bedroom wall.

All confusing, sorry can't be clearer. Calling the fitter today, will update with what he says.

 

[FiremanT]

All confusing, sorry can't be clearer. Calling the fitter today, will update with what he says.[/quote]

Make sure that the RGI has a gas fire ticket. Ask to see his card, and look on the reverse. It seems wrong and odd that he proceeded wih the install, knowing there was an issue with the flue. Early 70's precast flues are the least best flue types available.

 

[Agile]

On a 70s house I would not be at all surprised if the two flues went up side by side.

However, now you tell us there is a "vent tile". Sherbert and I had envisaged that it was a brick chimney !

There should be a flue connection between the top of the ( wall ) chimney and the ridge tile terminal.

I would expect they could easily have been crossed over by the builder. Not terribly important if you are on good terms with your neighbour but it does need to be understood.

Can you see your loft and maybe take a photo. Does the party wall extend to the loft?

Tony

 

[jj4091]

I've been told that ridge vents for gas appliances do not meet latest regs. Is that a myth or duff info. I just thought that if it is correct then this new fire should not be being installed whether the flues are crossed or not.

 

[Humdinger1970]

Hi again.

Spoke to fitter today. As Agile says, he reckons flues are indeed side by side. When they get into the loft space, reckons an angled block has been fitted the wrong way round, hence neighbours flu goes out of my vent.

Says the party wall will be so warm as when built, it would have been bricked right up against the flue with just a skimming of plaster inbetween, whereas now there would be a gap and plasterboard between the flue and the brick. Does that sound right?

Only in the daylight today have I inspected the roof and he has indeed fitted a new vent tile on the ridge without my knowledge or approval! It's like a ruddy bird house!

He's now coming on Saturday hopefully to inspect in the loft. To be continued...

 

[Agile]

I've been told that ridge vents for gas appliances do not meet latest regs. Is that a myth or duff info. I just thought that if it is correct then this new fire should not be being installed whether the flues are crossed or not.

I do know that they need to be carefully checked with the appliance makers to check suitability.

But apart from that I know that Gas Safe has not been happy with the number of problems in the loft space where the connection has been missing or wrongly supported and come away from the ridge tile vent.

Tony

 

[FiremanT]

I've been told that ridge vents for gas appliances do not meet latest regs. Is that a myth or duff info. I just thought that if it is correct then this new fire should not be being installed whether the flues are crossed or not.

Some fires specify that the flue must conform to the later BS EN 1858 rather than the earlier 1289. Later ones have a greater cross sectional area.