strapping down flat roof

[Glanmor]

Hi all,

quick question...

warm deck flat roof being installed, approx 6mx6m. Just relaised I've forgot to install roof straps along the side walls (at 1m) where joists run parallel to the side walls. These straps should have attached above 3 x joists and over noggings and the other end built into the wall.
Well, thats not going to happen now - the walls are already built and the joists have firring attched to the tops and OSB deck screwed in.

There is no wall plate on top of the inner skin.
There is wall plate on top of external skin but thats mostly for the purpose of a nailer (100x50mm) as roof perimeter for fixings/profiles. It will be an EPDM roof.

Strapping at the other walls is simple as it would take twisted strap on selected joist.

Any advice on how to remedy this please.

Thanks
G

 

[^woody^]

Why would those walls need [restraint] straps?

 

[Glanmor]

I was thinking of strapping down roof from flying off in strong wind rather than walls being restraint.
Oh hang on, should there be wall restraints too.

 

[Glanmor]

stumbled on this via google..

http://www.buildingregs4plans.co.uk/guidance_flat_roof_structure.php

Looks like wall restraints are also required after all.

 

[^woody^]

The straps you described are lateral restraint for the walls - which you dont need.

A flat roof is held down at the joist bearings not the sides

That link should be www.halftheinformation4plans.co.uk/stupid_guidance.php

 

[Glanmor]

Hahahahaha... absolutely brilliant!

Woody, you pretty much always provide answer on the issue in your return questions. Thank you for that.

I'm self build hence obvious questions. I will ignore side restraints and strap down joists ends with twisted straps.

Roof taking shape now. This weekend it will be mostly finding top of joists with 235mm Tek screws. Only trouble is joists are hiding behind 150mm insulation and two layers of 18mm OSB3 T&G. Few misses and there will be no need for roof light!

Cheers.