Suspended timbers floor query

[Homerdoh]

I'm in the middle of some alterations on my bungalow and have a few dilemmas, here's one of them.

I've taken up all of the floor at the back as it needed lowering in line with the new concrete floor of the utility room, I've fixed 6x2 joists with hangers and am ready to start boarding with 22mm t&g caberfloor, I was going to tight fit with 100mm celotex and foam fill all remaining gaps.

I've cleared all of the old debris, rubble, soil etc from underneath so it's spotless and there is a between 200mm and 300mm gap below joists.

Do I need a moisture barrier?

Also is this space best for my new wiring or should I drop down from the loft to each new socket/switch?

Any advice appreciated

 

[geraldthehamster]

I'm in the middle of some alterations on my bungalow and have a few dilemmas, here's one of them.

I've taken up all of the floor at the back as it needed lowering in line with the new concrete floor of the utility room, I've fixed 6x2 joists with hangers and am ready to start boarding with 22mm t&g caberfloor, I was going to tight fit with 100mm celotex and foam fill all remaining gaps.

I've cleared all of the old debris, rubble, soil etc from underneath so it's spotless and there is a between 200mm and 300mm gap below joists.

Do I need a moisture barrier?

Also is this space best for my new wiring or should I drop down from the loft to each new socket/switch?

Any advice appreciated

You don't need a vapour barrier - having said that, the foil on Celotex will act as one anyway. I assume you have good under-floor ventilation from air bricks?

As to the wiring I would do whichever is the easiest. How much do you need to replace or extend, and where are you taking the power from?

Don't enclose wiring within Celotex or expanding foam. Any junction boxes should be accessible.

Cheers
Richard

 

[Homerdoh]

Ok thanks so no barrier required.

There are three air bricks but I might put a couple more in, is there a guide as to how much ventilation per square metre?

Power will be from new consumer unit in kitchen, thinking about it now it will be better down from loft in oval conduit which will make it easier to replace any cables.

Thanks

 

[oldbutnotdead]

Building regs suggest 1500 sq mm per metre of wall or 500 sq mm per square metre of floor, whichever is greater. Sounds a lot but you get 1200 sq mm from a bit of 40mm pipe. Ideally you'd have vents in opposite walls (so there's continuous air movement).