air tightness and spots

M cebee

Does the electrician have to consider air tightness when installing spots?

Do spots have to comply with part L i think it is?

Thanks

BryanF

M cebee wrote: »

Does the electrician have to consider air tightness when installing spots?

Do spots have to comply with part L i think it is?

Thanks

I think it reads something like 'reasonable effort needs to be made' BUT you as the home owner or your arch should be looking out for such things and if your serious about air-tightness insisting the electrician use the sealed backing covers, and really carry round a role of tape to close any cuts made.
had you set an air-tightness level/performance spec?
is the main contractor liable if he doesnt achieve this standard?

M cebee

I am the electrician
im just wondering do i have to ensure air tightness

BryanF

M cebee wrote: »

I am the electrician
im just wondering do i have to ensure air tightness

yes you should

ensuring boxing for concealed services is
sealed at floor and ceiling levels and
sealing piped services where they
penetrate or project into hollow
construcions or voids

TDG L 2011 p29

gears

I would say talk to the home owner and/or architect that you are working for and work with them on this as you will need to make some allowance for down lighters. If they are using an air-tight membrane you will need to install the down lighters in an air-tight box which can be bought or made on site. Either way it is a detail which needs to be addressed and not something that would be covered in the average electrical quote or tender, I would imagine, so again talk to the home owner.

Tifosi

If the spots are downstairs do they require to be sealed airtight?

And if you build the spots in an airtight box, how will the heat from the light dissipate, especially with LV and Led Lamp sources, kind of curious that's all.

MicktheMan

Tifosi wrote: »

If the spots are downstairs do they require to be sealed airtight?

Generally yes unless the void has been made airtight by appropriate airtightness detailing/workmanship.

creedp

MicktheMan wrote: »

Generally yes unless the void has been made airtight by appropriate airtightness detailing/workmanship.

The only issue with this is that this area is supposed to be within the airtightness envelope and therefore there is no membrane on this ceiling which means its airtightness is not up to scratch in any case. I suppose the airtightness of the void depends on the airtigthness of the detailing around the joists or the hollowcore but unfortunately I don't think that sealing the spots will make that much difference unless you have put a membrane on the ceiling and then of course the upstairs floor as air will leak from the void up as well as down. Unfortunately, however, the airtightness to the cavity is often not what is desired ... I should know!

MicktheMan

creedp wrote: »

The only issue with this is that this area is supposed to be within the airtightness envelope and therefore there is no membrane on this ceiling which means its airtightness is not up to scratch in any case. I suppose the airtightness of the void depends on the airtigthness of the detailing around the joists or the hollowcore but unfortunately I don't think that sealing the spots will make that much difference unless you have put a membrane on the ceiling and then of course the upstairs floor as air will leak from the void up as well as down. Unfortunately, however, the airtightness to the cavity is often not what is desired ... I should know!

If the void space is within the airtight envelope (i.e. that the joists/hollowcore junctions are airtight and tested to be) then installing recessed lighting does not require any further airtight measures.
Imo, installing airtight membranes across intermediate ceilings shows a lack of understanding on how to airtight a building.
This is why deciding on and specifying airtightness detail before the building starts is v important.

creedp

MicktheMan wrote: »

If the void space is within the airtight envelope (i.e. that the joists/hollowcore junctions are airtight and tested to be) then installing recessed lighting does not require any further airtight measures.
Imo, installing airtight membranes across intermediate ceilings shows a lack of understanding on how to airtight a building.
This is why deciding on and specifying airtightness detail before the building starts is v important.

I agree and that's why I was thinking that airtightness concerns with spots on intermediate ceilings should not be a big issue. However, if the void isn't airtight then of course ........ but then will spots make it much worse? Its possible to purchase airtight spots but these cost about €25 each .. Ok if only have a few but a bit more problematic if you have 20 - 30 fittings or more.

Do-more

I don't think I can post the links here but if you Google for "Flanged Loft Cones" you should find products which are specifically designed for this task.

They appear to be made from fireproofed papier-mâché and can be easily sealed for air tightness and are designed to diffuse the heat from the down lighter and can be embedded in insulation. I'm not sure if in such circumstances you need to use IC rated (insulation covered) light fittings, best to check with the manufacturer of whatever cover you use.

I don't know which products are available in Ireland but when I enquired in the UK they were about £10 each!

On another forum I did see someone suggest the MacGyver-esque solution of using small terracotta flower pots but I couldn't find any with an Agrément Certificate.