Boarding Loft

I am having loft insulation going in and before they come I had to remove all my personal belongings and boarding from the loft.

I have discovered that the boards are laid on top on the cabling for the upstairs lighting circuits which as i understand could cause the wires to eventually break which would be a right PITA. I assume it's OK when I come to relay the boards to just use a chisel to put some small channels in the joists so the boards are not laid directly onto them.

Any advise greatly appreciated.

[Fallout]

Can't imagine it'd be a problem, so long as: you keep the channels to the absolute minimum, the wood doesn't split and you don't intend to put a grand piano in the attic. Assuming you're screwing the boarding onto the beams, you're reinforcing them anyway, so any channels would be at the centre of the structure and therefore not under much stress.

Edit: Kind of assuming you'd only be cutting at most 1/10th into the beam though.

DOubt you'll be able to relay the boards. if the insulation is being done to new standards it will be significantly higher than your joists.
Mines getting done next month and i fully expect to have to raise the floor level if i want to re floor it.
However technically you are not supposed to chisel joists to run cables any more, supposed to drill through the joist. Sure some mech tech could explain how a hole through a joist weakens it less than a notch out of its side.

It would literally be a notch the depth of 1.5mm lighting cable, so next to nothing.

Can you not relay boards over the insulation as my loft is tiny height wise and i don't have the option of raising the floor.

[Luckypants]

Originally Posted by daveyrach

Can you not relay boards over the insulation as my loft is tiny height wise and i don't have the option of raising the floor.

If the boards squash the insulation, then it loses much of it's efficiency and so becomes rather pointless. There is a reason it is all soft and squishy (hint: it's not so you can nail your loft boards down)

[Balky001]

I usually go through the middle joists for wires and notches for pipes but when the wiring is already done it's a pain especially if you can't get to one of the ends.

This old article is quite useful giving distances from support. Make sure your water pipes are insulated whilst you are there

http://www.telegraph.co.uk/property/...oorboards.html

[Wideboy]

On a professional project no I'd drill holes and rewire, on a personal project I'd make a small grove with a gouge or trimmer as obviously its not getting inspected and scrutinised so its my fault if anything happens

I'm not re-wiring, its only actually two cables (for the two front bedroom light fittings that are a problem and only a fraction of the loft is boarded, its a 4 bed house and there's only 12 boards up there just for a little storage, just to give u an idea. May just grove the joists and lay the 12 boards I have back down.

The maximum bending stresses in any beam are at the top and bottom surfaces so cutting a notch out of a beam top will have a bigger effect than drilling a hole in the mid height.
If you did not want to cut the beam, use a chizel and take a piece out of the underside of flooring board.
The main problem I see with either is to ensure that you mark the top face with a warning that live cables underneath.

I also predict (if not already in place) that there will be soon a restriction on running a cable surrounded by insulation. To me it looks a fire risk.

PS when I did mine, I moved the cables to the edges of the boards, cut a small bit out so that cable was not squashed and was visible from above.
It did not come above the finished floor level.
This also gave visual proof that insulation was below.
I use loft for storage and is not a room

Stephen McG. in Glasgow

[SoulKiss]

Originally Posted by Luckypants

If the boards squash the insulation, then it loses much of it's efficiency and so becomes rather pointless.

Originally Posted by daveyrach

May just grove the joists and lay the 12 boards I have back down.

If doing that - reboarding over the new insulation IF the new insulation is thicker then why bother.

You'll just reduce the efficiency of the insulation to that of the old stuff.