yet another rafter tie vs ridge beam question
yet another rafter tie vs ridge beam question
(OP)
Hi folks,
Reading the IRC 2009, it sounds to me like a ridge beam, designed to carry vertical load and spanning to posts etc, is NOT required if rafter ties are used - only a non-structural beam is required to facilitate rafter connections. Is this correct? In other words, the vertical loads are then assumed to be taken at the walls, not at the ridge (connection details aside).
Interesting how little information there is out there of the basics of ridge beams, rafter ties, etc. And yes, I read through the archives before writing this.
thanks,
Linnea
Reading the IRC 2009, it sounds to me like a ridge beam, designed to carry vertical load and spanning to posts etc, is NOT required if rafter ties are used - only a non-structural beam is required to facilitate rafter connections. Is this correct? In other words, the vertical loads are then assumed to be taken at the walls, not at the ridge (connection details aside).
Interesting how little information there is out there of the basics of ridge beams, rafter ties, etc. And yes, I read through the archives before writing this.
thanks,
Linnea






RE: yet another rafter tie vs ridge beam question
The rafter ties spacing is critical here. If 2 feet as in normal truss spacing, yes. But not at 8 to 12 feet as some tied rafter systems are. There, ridge beams WILL be required, regardless of any code stipulation.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: yet another rafter tie vs ridge beam question
RE: yet another rafter tie vs ridge beam question
Nick Deal, PE, SE
Michael Brady Inc.
http://www.michaelbradyinc.com
RE: yet another rafter tie vs ridge beam question
If there are any untied rafters, they would require a beam at the ridge.
BA
RE: yet another rafter tie vs ridge beam question
Then you will be getting into the use of purlins transverse to the collar ties, which at the longsr spans, would actually be more like trusses. To construct such a system without the purlins depends on the ability of the plywood, or specific roof diaphragm material, to span the gap. A four foot span would be the limit, depending on the snow load, without purlins.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: yet another rafter tie vs ridge beam question
What is wrong with tied rafters at 8' centers and steel or timber deck spanning the gap?
BA
RE: yet another rafter tie vs ridge beam question
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: yet another rafter tie vs ridge beam question
EIT
RE: yet another rafter tie vs ridge beam question
BA