Building notice / flat roof?

pacman8

Hi forum peeps,

Just wondering whether anyone has been through this before, here's the situation.

I have a flat roof extension that I'm planning on having redone, specifically, overboarding and replacing the felt with rubber. I've been reading the building regs and it isn't 100% clear to me whether I need to get approval given I'm not replacing the entirety of the roof (joists and insulation are staying put). The statement on the planning portal website is a little ambiguous as I don't know whether "roof area" means all layers or just one layer of the roof. To me, it sounds like I'd need approval? You need approval if:
"You are replacing/ repairing more than 25 per cent of the roof area, in which case, the roof thermal insulation would normally have to be improved."

I spoke to the roofer and he says no notice is needed as it isn't the whole roof that's being replaced. Some other thoughts here would be appreciated. Last thing I want is for this to come back to bite me in the future.

Thanks,
P

Doozergirl

Upgrading thermal insulation - which is what building control are interested in - isn't reliant on any of the substructure being replaced.

If building regulations states 'more than 25%' then of course your roofer is wrong when he says 'it isn't the whole roof'.

It's the insulation they're primarily concerned with. Some roofers can self-certify but my personal preference is to have inspections.

stuart45

If anyone is ever concerned about whether or not that they need regs, I would advise them to give their local BCO a call. In some cases the interpretation of the regs can vary in different areas on certain issues.
Doozergirl is correct though.

parking_question_chap

Its a bit of a joke when it comes to replacing flat roofs. All the regs care about is the thermal element, rather than actually seeing if the new roof is going to keep the water out. Is the surveyor going to stand there on the roof observing the roofer the the duration of the job? Highly doubtful.

Is probably more important in terms of getting a bit of paper so the solicitors are not a pain in the harris when you come to sell, rather that ensuring the job is properly done.

pacman8

All good replies - thanks folk. Looks like I'll be on the phone to the council tomorrow.

Doozergirl

parking_question_chap wrote: »

Its a bit of a joke when it comes to replacing flat roofs. All the regs care about is the thermal element, rather than actually seeing if the new roof is going to keep the water out. Is the surveyor going to stand there on the roof observing the roofer the the duration of the job? Highly doubtful.

Is probably more important in terms of getting a bit of paper so the solicitors are not a pain in the harris when you come to sell, rather that ensuring the job is properly done.

I think at least knowledge of the regulations and a willingness to be inspected is good initial starting point for a sign of some quality, though.

pacman8

The thermal insulation currently fitted looked good to me (but what do I know). Not sure how much that’d bump the cost up by if it did need redoing under regs vs just overboarding.

Ozzuk

I've been looking into replacing my roof and it seems if your roofer is certified they can sign off their own work - seems an easier option than going for BC.

All the quotes I've been getting for roofing work I've stated must be able to certify the work and noone has said anything to the contrary so I hope this isn't wrong!

Doozergirl

pacman8 wrote: »

The thermal insulation currently fitted looked good to me (but what do I know). Not sure how much that’d bump the cost up by if it did need redoing under regs vs just overboarding.

Having decent insulation in a roof is always going to save money.

You should establish what you have and how it compares to required uVaules under Building Regulations - bearing in mind that they are a *minimum* standard!

traineepensioner

pacman8 wrote: »

Hi forum peeps,

Just wondering whether anyone has been through this before, here's the situation.

I have a flat roof extension that I'm planning on having redone, specifically, overboarding and replacing the felt with rubber. I've been reading the building regs and it isn't 100% clear to me whether I need to get approval given I'm not replacing the entirety of the roof (joists and insulation are staying put). The statement on the planning portal website is a little ambiguous as I don't know whether "roof area" means all layers or just one layer of the roof. To me, it sounds like I'd need approval? You need approval if:
"You are replacing/ repairing more than 25 per cent of the roof area, in which case, the roof thermal insulation would normally have to be improved."

I spoke to the roofer and he says no notice is needed as it isn't the whole roof that's being replaced. Some other thoughts here would be appreciated. Last thing I want is for this to come back to bite me in the future.

Thanks,
P

Is the roofer just overboarding the existing felt? or is he removing the felt and overboarding the existing decking?....or removing and replacing the decking?

I assume that your roof is constructed as a cold roof, where the deck is ventilated and the insulation is between the joists.... Not a warm roof where the insulation is above the deck.

See https://www.planningportal.co.uk/info/200130/common_projects/47/roof/4
"Some repairs to flats roofs will not require an application for approval under the Building Regulations. However, if the roof with integral insulation is to be replaced then you may be required to upgrade this 'thermal element' of the structure and reduce the amount of heat that was originally lost, by upgrading the insulation."


From the above I would have thought that unless you're actually exposing the insulation then no upgrade is required.
I suspect that if you did add a warm deck to your existing ventilated cold deck it would have little thermal effect.:o