Insulated roof sheets/panels Class Q conversion

[Smith31]

Looking at converting a shed into a dwelling, it is currently roofed using standard 0.7mm corrugated steel sheets, which are fixed into steel purlins.

In order to meet building regs;

1) Could we simply overclad the existing roof with insulated steel sheets, screwed down directly to the existing sheets or would we have to fix a spacer bar between the existing sheets and the new insulated roof sheets to allow for air circulation?

2) Has anyone tried to build up an existing roof with rockwool type insulation before resheeting it with 0.7mm corrugated sheets?

The architect is suggesting we remove the existing roof sheets and replace them with insulated sheets, however this adds labour, netting and higher scaffolding costs to the project, so trying to avoid this route if possible.

TIA

 

[grainboy]

Do it once, , do it right,
Over cladding could create problems in the future,

 

[The Arable Farmer]

Overclad is a very standard practice, that's how a lot of the real big sheds are done. Can work out cheaper than composite panels even when new roofing. Trimform supply techbar system which is very good. Done plenty of it.

 

[The Stig]

I didn’t think you could alter external dimensions of the building under class q?

 

[Nearly]

I didn’t think you could alter external dimensions of the building under class q?

Can't go bigger footprint.
Upwards is open to abuse.

 

[designanddetail]

If the roof is in good condition then you could turn it into a built-up cladding system. You buy a specific ash grid system, fix it down and then rockwool and then fix a top sheet. Very common practice on new builds.

 

[Smith31]

If the roof is in good condition then you could turn it into a built-up cladding system. You buy a specific ash grid system, fix it down and then rockwool and then fix a top sheet. Very common practice on new builds.


View attachment 1091380

Thank you, do you know of any companies which sell the materials for the built up system? TIA

 

[designanddetail]

You could speak to someone like Luke @ https://www.evtekconstructionsolutions.co.uk/

They will come and survey your roof, then detail you the system and flashings etc, and supply you a full kit to install yourself.

 

[Smith31]

You could speak to someone like Luke @ https://www.evtekconstructionsolutions.co.uk/

They will come and survey your roof, then detail you the system and flashings etc, and supply you a full kit to install yourself.

Thank you, much appreciated