Sealing boiler flue through wall 3 storey high flat

[johnnyplumb]

Anyone know of a combi boiler with a flue that can be fitted/sealed through wall from inside only, ie 3 storey high flat with another flat Above so no access through roof.

 

[SimonJohns]

Any concentric flue

They were designed for that very reason

You drill a 5" hole, put the rubber seal on. And pass through wall

 

[johnnyplumb]

The flats are timber framed so 4 inch flue needs 6 inch sleeve ie 1inch clearance all Round. Would be difficult to seal with rubber seal.

 

[SimonJohns]

Speak to a decent manufacturer like Worcester or main or Baxi. I'm sure they will have a kit for it

 

[johnnyplumb]

I Thought about drilling a 6 inch hole from inside and stopping an inch short of Going through wall, then drill 4 inch hole through remaining brick, fit sleeve, then Only a 4inch hole outside which can be sealed with rubber seal provided. I know Regs say sleeve should be continuess and the whole thickness of the wall but what can you do if no manufacturers kit available.

 

[AWheating]

i would personally never leave a flue un sealed even with rubber dress fitted. its not air tight and water proof. I dont really do much private work but i know all contract work i have been on you would never be allowed to leave it un sealed.

3 storys high is not that high, use a ladder + apprentice.

 

[johnnyplumb]

never used to be a problem before condensing boilers arrived, as you could slope the flue downwards towards the ground. With flues now sloping back to boilers any weaknesses now show up.

 

[gasmarc]

some flues have the slope built in so no need to raise up . bosch recommend just using the rubber seal on the outside from memory , not an issue if sealed from the inside on a wall with no cavity. I would drill a 4 inch hole and put a small coke bottle on a piece of rope and lower to ground then attach flue ,then pull rope up with bottle at end of flue ,pull into situ and then lower bottle of coke ,works a treat

 

[GQuigley67]

I had a similar problem when contracting this week, ladders wouldnt reach and there was no way i was over stretching to seal it as he said to do so i just popped it through and pulled back with rubber weather collar and sealed from inside, some of the external wall broke off on the outside of the wall but nothing much i could have done to seal it without the proper equipment

 

[gasmarc]

If there is not a cavity and it is sealed inside it is not an issue , regarding flues in voids it could be argued that one should not have joints inside a wall cavity