Insulation added after second fixing!

[nomadicsoul]

Hi everyone.
I need a little advice please. Several months ago I first fixed and second fixed a timber frame loft conversion ( open plan living area and kitchen) for a friend /client. I haven't signed it off yet as I was waiting to install I new CU for him and for him to fit the kitchen. I fitted a kitchen ring final in 2.5mm, socket radial 2.5mm, 2x 6mm hob/oven supplies, a radial, and 2 lighting circuits in 1mm. And smoke detector.1mm. At the time it was simply kingspan with cables through timbers mostly not touching the insulation I used Reference method 102 for calculations. I have however returned to connect up an electric skylight and noticed that every cavity including the 18 inch floor space has been packed with wool insulation changing the reference method to 103. As we know a ring final should not be installed when using ref meth 103 and the radial 2.5m current carrying capacity will be reduced to 13.5A, the 6mm cables to 23.5A. The walls have been plastered and the tongue and grove flooring down and glued. Does anyone have any suggestions on what I can do to remedy this situation? Many thanks in advance.
Si

 

[ImpededLoop]

All you can do is derate the circuit breakers providing that the connected loads will not then exceed the rating of the circuit breaker.

It sounds like you've put plenty of thought into designing the installation which is great to hear

 

[littlespark]

Derate the breakers….. after producing a back dated test cert to say it was all right when you second fixed.

 

[timhoward]

I feel the pain on this one - lots of thought went in and they stuffed it up (almost literally) for you.
The other problem is that this is a loft conversion, and building regs will have been inspecting it. So this isn't really one to bend the rules too much on.
One creative thought - the merits of which can be critiqued!
If you change the first and last socket on the kitchen ring to a 13A FCU, split the ring in the middle, and feed from two 16A breakers on the basis of downstream overload protection..... then if the loads are neatly divided you get the max 26A of design current out of what is there then.

 

[nomadicsoul]

Tim Howard. I like that idea. Certainly an idea to consider.Thanks very much.

 

[Petej999]

Hi everyone.
I need a little advice please. Several months ago I first fixed and second fixed a timber frame loft conversion ( open plan living area and kitchen) for a friend /client. I haven't signed it off yet as I was waiting to install I new CU for him and for him to fit the kitchen. I fitted a kitchen ring final in 2.5mm, socket radial 2.5mm, 2x 6mm hob/oven supplies, a radial, and 2 lighting circuits in 1mm. And smoke detector.1mm. At the time it was simply kingspan with cables through timbers mostly not touching the insulation I used Reference method 102 for calculations. I have however returned to connect up an electric skylight and noticed that every cavity including the 18 inch floor space has been packed with wool insulation changing the reference method to 103. As we know a ring final should not be installed when using ref meth 103 and the radial 2.5m current carrying capacity will be reduced to 13.5A, the 6mm cables to 23.5A. The walls have been plastered and the tongue and grove flooring down and glued. Does anyone have any suggestions on what I can do to remedy this situation? Many thanks in advance.
Si

Were you aware of work undertaken whilst you were first fixing, if son down to you to sort the problem, I THINK.

 

[Petej999]

Hi everyone.
I need a little advice please. Several months ago I first fixed and second fixed a timber frame loft conversion ( open plan living area and kitchen) for a friend /client. I haven't signed it off yet as I was waiting to install I new CU for him and for him to fit the kitchen. I fitted a kitchen ring final in 2.5mm, socket radial 2.5mm, 2x 6mm hob/oven supplies, a radial, and 2 lighting circuits in 1mm. And smoke detector.1mm. At the time it was simply kingspan with cables through timbers mostly not touching the insulation I used Reference method 102 for calculations. I have however returned to connect up an electric skylight and noticed that every cavity including the 18 inch floor space has been packed with wool insulation changing the reference method to 103. As we know a ring final should not be installed when using ref meth 103 and the radial 2.5m current carrying capacity will be reduced to 13.5A, the 6mm cables to 23.5A. The walls have been plastered and the tongue and grove flooring down and glued. Does anyone have any suggestions on what I can do to remedy this situation? Many thanks in advance.
Si

Advice for what its worth study the entire spec for the building before you start any work.

 

[nomadicsoul]

Were you aware of work undertaken whilst you were first fixing, if son down to you to sort the problem, I THINK.

No i only discovered the insulation by chance. I didnt know it was going in . He added it for sound proofing apparently. But I am trying to sort the issue.

 

[nomadicsoul]

Advice for what its worth study the entire spec for the building before you start any work.

Thanks. We discussed insulation . The home owner added it after my work was done but as hes a friend i feel obliged to sort it.

 

[ipf]

Thanks. We discussed insulation . The home owner added it after my work was done but as hes a friend i feel obliged to sort it.

I'd say he's the one obliged to sort it out. Being a friend, it should be easier to get the point over to him........just how he's cocked your work up and how it needs to be put right. Good luck.