Rafter Bracing

[Jackhammer]

I need some advice...... My building span is 16'. I have my 2X6 rafters spaced on 24"oc with 2X8 ridge board.

Do I need to use purlins or any type bracing on the 8' runs? If so could someone show me a illustration of how this should be done.

[giddonah]

8' runs? You mean the two slopes of the roof? Isn't that what the plywood decking is for?

[Jackhammer]

I have a 5/12 slope with the rafters tied into a 2X8 ridge board. The ceiling joist are nailed alongside the rafters on the top plate.

There is nothing between the rafters and ceiling joist but thin air. Do I need any support in this area?

[Cole]

Ridge Ties and you could put 1 purlin on each side.

[Jackhammer]

Ridge Ties and you could put 1 purlin on each side.

At what distance above the ceiling joist should I place the "ridge ties", is this the same thing as collar ties?

How far out would I place the purlins from the top plate?

[Cole]

Sorry, yes those are collar ties.

How tall are your rafters?

[Jackhammer]

5/12........... A bit over 3'

[Cole]

I wouldnt worry about it, but when you get playwood ( :D ) on the roof, walk on it and see if it bounces to much for your liking. If you think it is moving to much put some purlins on.

[Jackhammer]

10-4, over and out.......Thanks again

[Jackhammer]

I wouldnt worry about it, but when you get playwood ( :D ) on the roof, walk on it and see if it bounces to much for your liking. If you think it is moving to much put some purlins on.

Does that mean I can forget about the rafter ties and the purlins???

[Cole]

Put collar ties ion every other rafter.

[Jackhammer]

Put collar ties ion every other rafter.

What distance up from the ceiling joist should they be placed?

Should I use 2X6, the same as my rafters?

[Cole]

2x4 or 2x6 is fine. We usually just cut them 4'.

You can do whatever size you want.

[Jackhammer]

Cole, would it be alright to put these collar ties about a foot below the apex?

I would like to have a little room of there to store junk.

[Cole]

Sure.

[Rich]

The closer to the peak you get the less strength they have. If you're ovall height is 3' - 1' from top is probably ok. Rule of thumb is upper 2/3's.

[Cole]

Simple Engineering.

The higher you go the less the collar ties are brunting the outward thrust of the rafters.

The lower you go the more the collar ties are taking the force of the rafters from the plates.