Loft installation methods

[adsmith]

So new build bungalow is to have 300mm loft insulation as told by building control. This means installation method 101 comes into place however as it's a bungalow all circuits including cooker ring mains etc will be installed this way as they come from the loft space down. This installation method 101 isn't ideal as cables will have to beefed up so much. So only other way is to use a different installation method. So I was just wondering what installation method you guys would recommend or a good way to install circuits in a loft that will have 300mm of insulation.
Thanks

 

[westward10]

Is this thread the same as this one?

Loft insulation and ratings

Hi guys New build small 2 bed bungalow to have 300mm of insulation in loft space. Obviously all circuits to be ran in loft and dropped. Circuits to be used are alarm circuit 6amp, lighting 25x 4w downlights 6amp, 2 x 32amp ring mains, 16amp boiler radial, 32 amp hob/oven circuit (undecided if...

www.electriciansforums.net

 

[adsmith]

Is this thread the same as this one?

Loft insulation and ratings

Hi guys New build small 2 bed bungalow to have 300mm of insulation in loft space. Obviously all circuits to be ran in loft and dropped. Circuits to be used are alarm circuit 6amp, lighting 25x 4w downlights 6amp, 2 x 32amp ring mains, 16amp boiler radial, 32 amp hob/oven circuit (undecided if...

www.electriciansforums.net

Yes I didnt get much reply on the last one so thought I'd try

Is this thread the same as this one?

Loft insulation and ratings

Hi guys New build small 2 bed bungalow to have 300mm of insulation in loft space. Obviously all circuits to be ran in loft and dropped. Circuits to be used are alarm circuit 6amp, lighting 25x 4w downlights 6amp, 2 x 32amp ring mains, 16amp boiler radial, 32 amp hob/oven circuit (undecided if...

www.electriciansforums.net

Yes I didnt get much of a reply on that post so tried posting a new one to a different area "wiring theories and regs"

 

[westward10]

Fair enough but having two threads along the same theme will confuse people. Do you want the other one closing as we can't have both running.

 

[adsmith]

Fair play I'll keep this one up then.
If I was to try change the installation method. For Instance fix a piece of wood across the rafters above the thermal insulation level and clip the cable direct to that then drop down through the insulation where the sockets are located would that be adequate as there would only be a small portion of the cable going through the insulation therefore I could use 2.5mm? Would that be adequate

 

[westward10]

I will close the other with a link to this one.

 

[Andy78]

Fair play I'll keep this one up then.
If I was to try change the installation method. For Instance fix a piece of wood across the rafters above the thermal insulation level and clip the cable direct to that then drop down through the insulation where the sockets are located would that be adequate as there would only be a small portion of the cable going through the insulation therefore I could use 2.5mm? Would that be adequate

See 523.9 and table 52.2 then use the factor as the value for Ci in your calcs.

 

[telectrix]

Fair play I'll keep this one up then.
If I was to try change the installation method. For Instance fix a piece of wood across the rafters above the thermal insulation level and clip the cable direct to that then drop down through the insulation where the sockets are located would that be adequate as there would only be a small portion of the cable going through the insulation therefore I could use 2.5mm? Would that be adequate

that's one way of doing it. it would be my preferred method. cables are above insulation and the drops could drop down in some short pieces of 2 x 2 trunking to give a bit of airspace around .

 

[Deleted account]

If your running cables through the loft where there is 300mm insulation which is normal for any house. Most efficient way is clipped direct. Nothing wrong with installation method 101.

Beefing up cables won’t be nessisary for the most part.

Do the calcs and you will see.

 

[PEG]

I would agree^,do the calcs,and see how far away it is....probably no worse than 10,000 other properties...

I would be surprised if they actually get 300mm put in,as it still means a bit of prep work.
It won't get above ceiling rafter height,at the eaves,due to ventilation requirements,so these are areas for loaded cables,if not a pain to access.

There also should be packing pieces and some boarding,as access for any future reason,would be troublesome,with 300mm of insulation,ready to be poked through a bedroom ceiling

 

[adsmith]

Thanks guys. I've decided to just clip direct up out the way of the insulation and obviously the drops have to pass through the insulation which is unavoidable. And all drops are attached to battons to prevent anyone pulling on them or kicking them out of place. Would you say that's sufficient.

 

[Zerax]

Thanks guys. I've decided to just clip direct up out the way of the insulation and obviously the drops have to pass through the insulation which is unavoidable. And all drops are attached to battons to prevent anyone pulling on them or kicking them out of place. Would you say that's sufficient.

Sounds fine to me... it's certainly far better than you'll find in most new builds !