Building regs for flat roof pitch?

17 Feb 2014
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United Kingdom
Having our garage converted at the moment and the builders have had to re do the roof in order to install the required insulation. They've put in a rubber roof but there is no fall line on the roof, it is completely flat (well actually it is quite uneven) but there is no pitch. Can someone tell me if building regs require a fall line or if it is only recommended that there should be one?
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So it’s being converted to habitable space and is being inspected by Building Control?

Why didn’t they add a fall during the works to redo the roof?

I’ve rarely ever changed the roof finish when doing garage conversions unless it’s been shot as usually BC will accept insulation between/under the existing joists.

I think, (someone else may care to pluck up) that it’s actually a recommendation to have a fall rather than being mandatory.
Yep habitable space. Building inspection was carried out early in the build. The redo of the roof was to allow for insulation as putting below roof would make the ceiling too low as the floor needed to be raised as well and also I assume to assist with the extension as we extended the garage by 1.5 metres.
If you have used a rubber system (EPDM?) then the inspector should require it to have been installed in accordance with the system manufacturer's instructions. Normally a fall is required. And if close to a boundary, it's suitability in terms of resistance to fire spread should be confirmed.
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Have just been told by the builders that they are going to redo the roof and ensure there is a pitch, they are saying an inch for every 40 inches, I assume that's correct, perhaps someone could tell me? Why they didn't do this in the first place I don't know!!?? Would have saved them a lot of money. They told me what the pitch should be this morning when I questioned it, my first thought was if you knew why didn't you do it the first time???!! Maybe they didn't know and only just found out from googling it. Doesn't fill me with much confidence. They seem to be conscientious though and wanting to sort out the things that I'm not happy with, which at least is good.
Yeah that's what I thought. I'd been bracing myself all weekend for a confrontation with them over it, but very glad they admitted fault with little effort on my part, although they haven't apologised yet, but I'm just glad they're sorting it. So how do you work out what 1:40 would be. Say the roof is 10 metres (not actually sure how long it is), what would the drop be?
1:40 is steep for a flatty and is gonna look horrendous from the side. 1:80 is more reasonable.
The garage can't be viewed from the side as it is joined onto our neighbours garage, but I see your point.

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