cable run perpendicular to loft joists.

[ianphilip007]

hi just been to look at a job, have to get a cable accross 4 joists ( perpendicular) now i know drilling loft joists is a no no, the cable run will be in an area of the loft not used for storage and the customer has no intention to board out the loft is there anything wrong with laying the cables accross the joists, neatly and secured under the existing insulation? ( 1.5mm 6amp lighting)

 

[MarkieSparkie]

Notching and/or drilling ceiling and floor joists are both allowed under the Building Regulations Part A.
Notching joists in top edge only, in the zone 0.07 to 0.25 of the span, maximum size 0.125 x depth of joist.
Drilling joists on the centre line only, in the zone 0.25 to 0.4 of the span, maximum size 0.25 x depth of joist, holes in the same joist should be at least 3 diameters apart.
No notches or holes should be cut into roof rafters, other than at supports where the rafter may be birdsmouthed to a depth not exceeding 0.33 x rafter depth.
See EGBR 2.3.2 and 10.1.1 for details.

 

[DaveyD]

Can you not put into trunking and clip out the way under the eves. Even if boarded it can butt up to the trunking.
That's what I do.