Flue distance from structual opening

[basildog]

My mate (structual engineer ) wants his new boiler in the kitchen but the distance from the window reveal to the wall is only 220mm now I know the flue will be elbowed up and away from the opening so that is not the question he has in his head that there should be 150mm clear before forming flue opening I always thought it was 100mm which is still pushing it !
Any thoughts ?

 

[basildog]

That is the answer I expected but the question is the opening not the termination ?

 

[Dotty]

300mm termination to opening, above, below or beside.

 

[basildog]

Yes I know that I am not explaining it very well the flue will be terminated away from the opening it is how close to the window the core can be I suppose is really the question .
combustion air can be drawn 150 mm from an opening I know but again in this case that will not work either as I have seen a plume kit used in that case this is about purely the hole ?

 

[Atouchofgas]

How close can you core to the structure of the window is what your asking?

 

[basildog]

How close can you core to the structure of the window is what your asking?

Yes why didn`t I think of that ! Doh

 

[AlexGas]

Natural or fanned draught?

 

[basildog]

Fanned but that is not the issue it is the proximty of the core to the edge of the structual opening ?

 

[AlexGas]

Fanned but that is not the issue it is the proximty of the core to the edge of the structual opening ?

That's right! 150mm
Your mate is right!

 

[dancinplumba]

And not under the lintel

 

[AlexGas]

And not under the lintel

Unless one really, really wants to. Have to stand way back though!

 

[Ermintrude]

Or through it

 

[basildog]

Unless one really, really wants to. Have to stand way back though!

We all think that but the funny thing is I was talking to him about just that and actually it can normally be proved that the weight i.e the load above will be cantilevered to the opposite side even if you removed the bricks below one side .
He is a bit of a whizz with calcs as you would expect often doing silly calcs when bored ,down to proving an vertical broom stick wil carry a load of more than a tonne ! Why would you bother ?

 

[AlexGas]

We all think that but the funny thing is I was talking to him about just that and actually it can normally be proved that the weight i.e the load above will be cantilevered to the opposite side even if you removed the bricks below one side .
He is a bit of a whizz with calcs as you would expect often doing silly calcs when bored ,down to proving an vertical broom stick wil carry a load of more than a tonne ! Why would you bother ?

You are the Boss. Go for it.

 

[Scott_D]

Get him to core the hole for you?

 

[basildog]

I am not even doing the job he is a mate and another mate was there this morning to do platering etc they wanted advice on where the flue will be going I am now thinking he will have to take another route which then throws up a whole new set of problems !!!!!!

 

[myles]

From what I understand if for example it states 300mm from an opening then the actual core hole needs to be 300mm away not the flue terminal. Im sure it was in the June 2014 edition of Registered Gas Engineer not long ago about it, Basically it stops you being able to use a plume kit to get the terminal the required distance away etc.

 

[tamz]

Dimensions A, B and C are 300mm for a fanned flue

 

[basildog]

In reply to Myles
That is not how I understood it and have seen a few installs not complying with that then !
It was alaways 150 mm for air and yes 300 for poc but a flue could be elbowed externally or as you say a plume kit used .
Is this another rule change ?

 

[myles]

Just checked tb016 says plume management kit must not be used to circumnavigate standards. My lecturer pointed it out and he is a gs inspector too that was his take on it so I stick to that lol

 

[basildog]

Just had him on the phone again after I gave him the good news !
2 options now as window opening to patio door only 560 mm so going between not an option .
Ist option is wall mounted boiler below window which I doubt will fit
2nd option flue into ceiling void trimming out 2 joists
Original boiler was wall mounted below window and sounds like an old balanced flue from his description

 

[basildog]

My take on it is that you are ok forming or coring 150mm from a structual opening but as you say a plume kit cannot be used but an elbowed flue termination can as long as the termination point is 300mm from opening ?

 

[myles]

I think the main point he was making was the actual core hole being the required distance away as that is classed as the flue termination from the building. I just make sure the hole is required distance away that way nothing can be said! It may have been updated in BS after TB016.

 

[basildog]

I get what you are saying but am sure that is not the case as the termination is where the poc`s` are discharged surely ?
Better tell him to get night storage heaters I think !
I can see why a plume kit is not allowed but surely a purpose made flue elbow is ?

 

[myles]

I think it could be to do with if the flue failed at the exit point then the 'outlet' could then end up too close to an opening, you should install the flue with the hole at minimum distance as though it would be a horizontal terminal in the first place and then route it along whichever route is required.

 

[basildog]

I have just read the technical data for vaillant variable termination kit and that seems to blow all the regs and rules out of the window ??????
Confused . com

 

[myles]

Manufacturers instructions overide everything

 

[basildog]

Yes a phone call to them may be in order I think !
Has anyone ever used one when in a fix then ?

 

[basildog]

You have to love all these so called rules and regs as this all seems to make a total nonsense of them all ?
My mate now says core it 25mm from opening and sleeve flue through 150mm steel pipe or box section that will now carry load not there really is any .
This all ok until Mr I go by the standard rules and that is 150mm and 300 mm respectively turns up to do a service or gas safety check this will do his bonce in ?????

 

[AWheating]

some manufacturers allow you to be 150mm from a structual opening if you plume away. Worcester bosch being one.

 

[kozak1968]

As said already, check the manufacturers instructions on a particular boiler. You can download most installation instructions.

 

[basildog]

some manufacturers allow you to be 150mm from a structual opening if you plume away. Worcester bosch being one.

That is what I mean you get so many mixed opinions on all these regs it seems that they all think they are right ?

 

[GrahamM]

That is what I mean you get so many mixed opinions on all these regs it seems that they all think they are right ?

As mentioned the Manufacturer instructions is king here then you look to regs.
Worcester to name one allow you to put your core 150mm from building fabric as long as plume kit takes the flue discharge at least the standard 300mm from the opening.
This is not a complicated issue to grasp.

 

[basildog]

No not complicated but then you get those that say they will only do as regs state and gsr state in tb`s etc nothing is ever simple .

 

[tamz]

Bas you know as well as i do what will be structurally safe. Sometimes i think they write the regs for the brain dead but at the end of the day we need to follow them.
In my own house (cobblers bairns) i do as i please and know what is and is not safe but out in the big bad world i'll clamp down on anything that isn't as it should be in the books.
Btw look at an Ideal logic or a Glow worm with a rear flue.
It will save a lot of hastle in the future as they can be stuck below the window:wink: