Advice on gas flue inspection hatches please

jennifernil

Our daughter will be renting out her flat soon and has been advised that she needs to fit some inspection hatches as she has a concealed flue pipe.

The pipe runs below ceiling level from the boiler, which is in a cupboard on an internal wall, to the external wall of the room, a distance of around 3.8 metres.

The pipe is then boxed in, giving a plasterboard duct that hangs below the level of the ceiling in the rest of the room.

We have read that the hatches should be at least 300 x 300mm, but the boxed in bit is not quite as much as that on any face, and behind the plasterboard there must be some timber on which the PB is fixed. This therefore limits the size of access hatch which could be fitted.

Will it be acceptable to fit oblong hatches instead? With the smallest dimension being limited by the available space on the existing duct?

On that length of flue, we presume 2 hatches evenly spaced would be suitable, is that correct?

Do the hatches need to be fire rated? The flat is a ground and lower ground duplex, the boiler is on the lower floor. The kitchen sits immediately above. We presume the PB ceiling above the duct, at the level of the rest of the ceiling, is intact, but would be able to check that out if it makes a difference.

diywhynot

jennifernil wrote: »

Our daughter will be renting out her flat soon and has been advised that she needs to fit some inspection hatches as she has a concealed flue pipe.

The pipe runs below ceiling level from the boiler, which is in a cupboard on an internal wall, to the external wall of the room, a distance of around 3.8 metres.

The pipe is then boxed in, giving a plasterboard duct that hangs below the level of the ceiling in the rest of the room.

We have read that the hatches should be at least 300 x 300mm, but the boxed in bit is not quite as much as that on any face, and behind the plasterboard there must be some timber on which the PB is fixed. This therefore limits the size of access hatch which could be fitted.

Will it be acceptable to fit oblong hatches instead? With the smallest dimension being limited by the available space on the existing duct?

On that length of flue, we presume 2 hatches evenly spaced would be suitable, is that correct?

Do the hatches need to be fire rated? The flat is a ground and lower ground duplex, the boiler is on the lower floor. The kitchen sits immediately above. We presume the PB ceiling above the duct, at the level of the rest of the ceiling, is intact, but would be able to check that out if it makes a difference.

Contact fluesinvoids@gassaferegister.co.uk

jennifernil

Any other advice?

vaio

Covers are so gas man can visually inspect flue, the 300 x 300 is recommended but if the duct is smaller than that then best endeavours will apply and say 300 x 150 will be ok so long as it allows inspection.

Likely problems are at joints so I think the guidance calls for inspection access within a metre of any joint

Johnandabby

Access hatches have to be within 1.5m of any joint, but have to be realistically installed to give sight of the joint from the hatch. If it was me, I would make a series of penetrations along the boxing in order to establish all joints and then install hatches right where they are.

Also ask the opinion of the person who will be servicing the boiler, as the hatches are there for them - no point going through the hassle by yourself only to find that they mark the boiler as 'at risk' and turn the boiler off because they don't agree with you. Not the best way to start a rental agreement...

vaio

Depending on the construction & decorations it might be worth thinking about making the entire side panel removable

jennifernil

Thanks for all the info and suggestions.

Reluctant to mess around too much with the boxing in, which is made of plasterboard, as the decorations are otherwise perfect, so deciding on the position of the hatches is the tricky bit.

With a length of 3.8 metres, if we put the first hatch 1,2 metres from the cupboard, and the second one in the middle of the remaining 2.6 metre space, that would mean no part of the pipe would be more than 1.3 metres from the centre point of a hatch.

With a long thin side to the duct, I doubt having the whole side removable would be wise.

We do have a "thing" with a little camera on the end which can look into small spaces, so we could try using that to see if we can better locate any joints before making any holes.

Does it matter whether the hatches are on the underneath of the duct or on the vertical side of it?

vaio

It's seems it's subjective so as Johnandabby mentioned above it might be worth getting your chosen gas inspector's views on number & placement of hatches

jennifernil

Yes, good plan.

Seems we may be looking for a new boiler now as the current one needs a repair which may not be worthwhile/economic on a 12 year old boiler.

Need some pointers as to best/most reliable make.....or those to avoid! Will start a new thread.