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Position of Wago Lightbox in loft conversion
Anonymous user 01/03/2024 - 3.00 PM
In the middle of a loft coversion, I'm installing 100mm PIR in the roof with 50mm airgap roof side. Building control have specified they want the layers to be: 1. 100mm PIR 2. Foil quilt 3. Batten 4. Plasterboard I have LED downlights, each with a Wago Lightbox, should this junction box sit on the roof side of the PIR? If so does that mean I then need a 2in hole in the PIR and foil quilt, so that it can be accessed? But then weaken the insulation and vapour control? Is there a junction box that is less than 1in in height to sit in batten layer?
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2 Answers
Anonymous user
The junction box should be located behind the ceiling, for future access.
This junction box measures 22mm in height, so should fit ok in a 1 inch gap.
https://www.cef.co.uk/catalogue/products/460754-5-amp-lighting-connector-box-white
Answered27 January 2023
3
StrangLX
Rating: 5 out of 5
The last time I took the time to research this I found guidance directly from celotex and kingspan the manufacturers of PIR boards instructions say that recessed lights should not be installed in or touching the insulation board…. In fact they don’t want you cutting holes in it for down lights at all., with that in mind you will need fit a false void by battening off and plaster boarding, the void should be deep enough to accommodate the recessed lights and junction box according to the light manufacturers instructions.
Here’s a link to kingspans guidance on the subject of recessed lights.
https://www.kingspan.com/gb/en/knowledge-articles/how-to-fit-spotlights-recessed-lights-and-downlights-in-insulation/
Answered26 February 2023
1