putting in a support brace

[bomberns127]

hello all, i have had a kitchen built, block outside and timber frame inside, how big can you go before the roof needs a brace in the middle to stop spread?
the ext is 5m x 5m ext size, but the kitchen area is 3.7m along 1 side because i have a timber framed wall going to the middle of the ext which will be a toilet/utility room on the same side which is 2.4m x 1m.
effectively i take this means i have reduced the size of the kitchen roof to 3.7x 5m, is this correct?
i know putting 1 in wont hurt but open ceilings look the dogs danglies.

it is a normal tiled roof with 4 velux windows in, do i need to brace the roof/walls, need to know before plasterboard goes up.

thx for looking

 

[jeds]

You either need a ridge beam or the rafters need to be collared. To be effective a collar needs to be fixed to the bottom third of the rafters.

 

[bomberns127]

hi jeds, thx for the reply what do you mean by collared?do you mean fitting a beam a third up from the wall going from 1 side to the other?
the roof has a gable end, the rafters have a ridge beam running front to back, do you mean doubled up underneath the one in place already?
the joists around the velux windows are doubled up so its strenghtened at those points
thx again for the reply,

 

[jeds]

do you mean fitting a beam a third up from the wall going from 1 side to the other?

Yes.

the rafters have a ridge beam running front to back

If the ridge beam is structural and properly designed/calculated you don't need anything else.

 

[bomberns127]

Thanks jeds, just to be on the safe side gonna put in some braces, had a roofer take a look and he said even though the ridge installed looks OK he would install some if it was his place, so I'm gonna install a couple and make a feature of them, thanks for your help jeds.