Flat roof repair

Seasalt3

We've got an extension on our house added in 1987 with a flat roof.  The roof is showing signs of deterioration with cracks in the felt. The boards are still in good condition.  If we just have the felt replaced to repair the cracks do we need building regs?    All the roofers I've spoken to say if we just replace the felt this would be considered a repair but if the boards needed replacing then we'd have to upgrade the insulation and obtain building regs.  Any advice please?

Tucosalamanca

Find better roofers?
You almost certainly don't need building regs approval unless the extension forms a significant proportion of the entire roof. Building Regulations: Work to an existing roof - Roof - Planning Portal
It's always good practice to upgrade insulation if the opportunity arises (you now have this opportunity).

It's routine work and any good roofer should be giving you this advice.
You probably have a cold roof design (insulation under the deck). These frequently have ventilation problems leading to condensation and damp.
Warm roofs (insulation above the deck) are now standard practice and what Building Regs would generally expect.
Sheds and garages are the only flat roofs that we don't insulate as standard.
For the modest uplift in cost, you'd be crazy not to, imo.

Doozergirl

Why would you not upgrade the insulation?  A roof from 1987 probably has none to speak of.  

You want to save money on building control but not on the heating bills for the lifetime of that roof? 

Seasalt3

Thanks for your comments.  The cost of a warm roof is significantly more than just replacing the felt and not sure if it's worth it.  We don't have any problems with the heating.  The room holds the hest perfectly well. I've no objection to paying for building regs if needed and just wanted to know if it's necessary if just replacing the felt.