Chimney building regs query

Sticky toffee

We built a new house and moved in August last year. Our only heating source is a stratford arrow solid fuel stove connected to solo rads and it works very well. We built a double flue chimney with the 2nd flue not in use, but we would be able to connect to it if we ever wanted to put a range in kitchen.
Around the end of November we had problems with smoke in the sitting room. There is a 90' bend coming out of back of stove up into chimney, I detached the cover inside stove and cleared bend and this solved for a while. I seen small bits of what looked like concrete but thought it must be left over from build.
Every now and again we would hear stuff falling down and I would clear neck of stove. We knew there was a problem but because of weather being so cold decided to put up with inconvenience of clearing it every day and get problem solved when weather improved. We also had a chimney guy look at it in Feb, problem appeared to be one of the clay flues had somehow broken and bits of it and micafil insulation were falling down, again because chimney would be out of action for almost a week during repair we wanted to wait for milder weather.
In July/Aug we got a couple of more chimney companies to look at it and give us quotes. We also spoke to builder as it looked like a faulty flue liner went in. He agreed to open up chimney and reline it, but we never heard from him again.
We had to get it fixed so hired a professional chimney company who opened chimney at bottom and cleared everything out and put up a new flue. It turns out the builder had not put a firewall between the set of flues and one of the flue stacks about half way up and leaned over so instead of being stright up it bent and had collapsed on itself.
My query is should the builder have put a firewall between flues and was he right to use micafilas opposed to sand/cement/lime mix? What are the building regs with chimneys and if he got it wrong should my engineer have picked up on it?

We are very annoyed as this was a brand new house. According to the chimney company the house could have gone on fire because of lack of firewall and we had a carbon monoxide alarm which went off several times over winter.
Any advice much appreciated!

sydthebeat

yes there should have been a minimum of 100mm blockwork between the two flues.

paragraph 2.14 of TGD J 1997 clearly states this. see here

"The thickness of the walls of a brick or blockwork chimney, excluding the
thickness of any liner should be at least:

(a) 100 mm thick between one flue and another,"

Trying to find liability is another story completely.

Yes, by right the engineer should have spotted it because they are the ones stating that it is constructed in 'substantial' compliance with building regulations. its a matter of opinion as to what substantial actually means, but in this case i think its clear that the de facto compliance was not met (but who am i to say so?). The whole 'opinion on compliance' certification system we have has been viewed as inadequate and defective as far back as 2008 by teh national consumer agency. see here especially pages 4, 23, 27 and 28

secondly, its the responsibility of the builder to build in compliance with the building regulations. So i would see this as being the builders fault in the majority.

however, thirdly, ultimately the onus is on the owner to ensure the build is being carried out in accordance with the building regulations. If this is a contract build then the clauses of the contract will clearly state that is the contractors responsibility to comply with all current building regulations. this would be a legal documented 'handing over' of responsibility to a nominated party.

Is this the case here?

Sticky toffee

Thanks Syd, no this was a self build where I built a timber frame and hired very reputable blocklayers to do the block work.
I paid an engineer to oversee the build and make sure all the building regs were adhered to. I don't have any contracts between ourselves and builders or with engineer. Big mistake I now know, but assumed these guys have been working many years and would be professionals in their respective specialties.

Slig

Sticky toffee wrote: »

Thanks Syd, no this was a self build where I built a timber frame and hired very reputable blocklayers to do the block work.
I paid an engineer to oversee the build and make sure all the building regs were adhered to. I don't have any contracts between ourselves and builders or with engineer. Big mistake I now know, but assumed these guys have been working many years and would be professionals in their respective specialties.

Self regulation is no regulation. Contracts between builders/professionals and clients have been largely ignored in many cases as everyone has relatives and friends in some field of the building industry that can be called on to do the odd job. As mentioned above Engineers/Architectural Certs are only issued on "substantial compliance" and is a very loose system.

igilvarry

Is this also specified somewhere in Building Reg's as I would like to reference this.

sydthebeat

igilvarry wrote: »

Is this also specified somewhere in Building Reg's as I would like to reference this.

yes

chimney heights are referred to on page 6

igilvarry

sydthebeat, I read p6 but still unclear for me.

So if I look at p6 it indicates for a flat roof that the height of the chimney should be a minimum of 1,000mm but then what about the minimum height of pot on top of chimney?

sydthebeat

why is there a question regarding the pot on the chimney?

Theres only so many different pots available on the market. The building regulations doesnt influence these products fitness for use.

The chimney must be a certain height, the pot is simply a means to exhaust the smoke and finish the flue.

interestingly, HOMEBOND suggest more stringent chimney heights to ensure proper 'draw' from the heat source. These can be found in the homebond manual.

igilvarry

sydthebeat: the background to the question is a chimney pot was selected without my involvement by the builder & architect. I would prefer to cut it so that the pot is not as high but I don't know how much I cut it back to without contravening the regulations.

sydthebeat

igilvarry wrote: »

sydthebeat: the background to the question is a chimney pot was selected without my involvement by the builder & architect. I would prefer to cut it so that the pot is not as high but I don't know how much I cut it back to without contravening the regulations.

The regs refer to the 'outlet' of a flue pipe not being less than 'x' m above roof level.

Therefore it doesnt matter what you cut the pot down to.
The regs dictate the point at which the chimney stops and the pot (or outlet) starts. This measurement must exist on site, regardless of the pot.