Roof terrace and building regs

TheGreenFrog

ThisIsWeird said:

When was the extension built, and are the details shown on the LA's Planning Portal? If so, it'll hopefully indicate the roof structure used.
We had an ext built around 5 years ago, and french doors from the loft bedroom opens out on to them. No concerns at all about walking around on there, or taking beanie bags out for a sit.
What kind of decking is going out there, tGF?
And what material is the roof outer made from?

I don't know how old the extension is, but probably pre-war.   Roof was bitumen but was leaking so they put some rubber sheeting over it apparently.   Decking as yet undecided.

stuart45

If it's been leaking for a while there's a good chance that the joists are damaged and more likely to fail. 

travis-powers

I’d be uncomfortable about fitting any kind of decking on a rubber roof, even on fleeced backed.
 First port of call would be inspection of joists the increase of load is substantial, I’d be looking for a new builder.
 

FreeBear

TheGreenFrog said:

ThisIsWeird said:

When was the extension built, and are the details shown on the LA's Planning Portal? If so, it'll hopefully indicate the roof structure used.
We had an ext built around 5 years ago, and french doors from the loft bedroom opens out on to them. No concerns at all about walking around on there, or taking beanie bags out for a sit.
What kind of decking is going out there, tGF?
And what material is the roof outer made from?

I don't know how old the extension is, but probably pre-war.   Roof was bitumen but was leaking so they put some rubber sheeting over it apparently.   Decking as yet undecided.

Timber was in short supply between WWI and WWII. Joists from this period could be as small as 75x50 (3x2"), maybe as big as 150x50 (6x2"). If the ceiling below is still the original lath & lime plaster, it will probably crack and collapse within a few months of the terrace being used. Even if it is a more modern plasterboard ceiling, cracks along the board joints could develop, and nails "pop". The best way to avoid these types of problems is to install a completely new deck isolated from the roof below. This is where a structural engineer is essential - He/She will advise on the timber sizing if the roof deck is not suitable.

twopenny

How is the roof going to be maintained if there is decking and  joists over it?

If not installed properly it's going to keep the area damp which can lead to the roof wearing before it's time.

stuart45

You normally renew the roof covering and build the deck in sections that can be taken up from time to time for maintaining it.

Emmia

How do the downstairs neighbours feel about a deck on a roof/extension they've paid for?

thegreenone

Planning and Building Control are different departments who rarely, if ever, talk to each other.    Just because Planning has been granted, it doesn't mean you can plough ahead and it sounds as though it would most definitely need BR.  Who owns underneath?

I've told the story before:  Nephew wanted to completely gut and rejig his house and put three beds upstairs. 

His "mate at work" did the plans on the latest whizz-bang version of Autocad and planning was passed.  Nephew asked my husband (an SE) to do BRegs.  Husband declared the plans unbuildable and had to completely redraw, moving the staircase (not enough head height) and consequently had to drop to two beds upstairs.  Mate laughed that Husband only had Autocad 9 (he didn't need latest at home) but he redid and Nephew had to resubmit.  Planning and BR passed (on lowly AutoCad 9) but only after a lot of work by Husband.  

Please make sure your daughter is not a Nephew.  If you see what I mean?