Vaulted ceiling roof beam size

[martinsutton]

Hi -
first post so just like to say thanks for all the useful info I have been reading.
I am building a glazed extension with a vaulted ceiling, the roof will be triple glazed sealed units. The length of the roof beam between supports is 5.4m, the width between wall plates is 4.4m.
I intended running a timber ridge beam but I am now looking at a steel beam as timber was getting huge.
It's a long time since i completed my engineering degree and haven't used the knowledge since ! Anyway, I calculate that I need a 203x102x23UB ridge beam.
Running from this to the wall plate (no purlins) will be 125 x 75mm rafters @ 900crs. supporting the triple glazed units (using 30Kg m2).
Both ends of the ridge beam will be supported by brick piers.
Can anyone give me a thumbs up to these calcs??

 

[noseall]

you mention unsupported ridge beam length, the distance between wall plates and 5"x 3" rafters at 900mm centres. what is the actual length of the rafter, or at least the pitch of the roof?

 

[martinsutton]

hi,
thanks for the reply, the actual unsupported rafter length is 2.4m with a roof pitch of 25 degrees.
I intend birdmouthing the rafters over the steel at the ridge and at the wall plate.
cheers

 

[martinsutton]

anyone any ideas ????

 

[noseall]

where is shytalkz when you need him?

woody....!

 

[martinsutton]

just found this old post with shytalkz responding:

//www.diynot.com/forums/viewtopic.php?t=132592

ridge beam size quoted is a little leaner than i worked out but my span is slightly larger so it looks reasonable - I like the flitch plate idea for a full timber look.