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Old 08-07-2008, 11:55 PM   #1
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ridgebeams, need some help


i have a few questions on ridgebeams, if a person is building a new house, lets say 40 foot long not counting lookouts, and is using 20 foot long members to make the ridgebeams, can the members just butt against each other or do they have to be fastened to each other? do they have to be 2x12s? im assuming a house has to have a ridgebeam if there are no trusses

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Old 08-08-2008, 07:40 AM   #2
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ridgebeams, need some help


If the ridge is forty feet I will order a 42' LVL for the ridge. but if using conventional lumber yes the ridge must be butted and a rafter should be placed over the seam. I have seen butt seams in a rafter bays with some blocking along side. I my self would never do it.
as far as the width of the beam ,I always order the next size up from the rafter. 2x10 rafter i would order 2x12. reason? the rater cut should have full bearing on the ridge. BOB

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Old 08-08-2008, 08:10 AM   #3
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ridgebeams, need some help


The condition you're describing occurs in nearly every home I inspect. In most cases it is not a problem.

To consider a home "conventional" construction, the ridge is basically self-supporting, because the rafers are tied together at or near the plateline by the ceiling joists. With the rafters tied, the ridge isn't working very hard at all.

However, when the ridge is taking load or when it is spliced, the loads must be transferred to a bearing location, usually a bearing wall. Typically a doubled or T'd 2x6 is installed under the splice. A rafter is not required at the splice.

Most homes I see built are not following the prescriptive measures in the code for roof framing because the roofs are not "conventional" throughout. The engineers are normally requiring their ridges to be supported to bearing at 48"oc. LVL/PSL ridges are normally not used unless a vaulted ceiling prohibits installation of struts to mid-span bearing points.
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Old 08-08-2008, 08:28 AM   #4
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Quote:
Originally Posted by thekctermite View Post
The condition you're describing occurs in nearly every home I inspect. In most cases it is not a problem.

To consider a home "conventional" construction, the ridge is basically self-supporting, because the rafers are tied together at or near the plateline by the ceiling joists. With the rafters tied, the ridge isn't working very hard at all.

However, when the ridge is taking load or when it is spliced, the loads must be transferred to a bearing location, usually a bearing wall. Typically a doubled or T'd 2x6 is installed under the splice. A rafter is not required at the splice.

Most homes I see built are not following the prescriptive measures in the code for roof framing because the roofs are not "conventional" throughout. The engineers are normally requiring their ridges to be supported to bearing at 48"oc. LVL/PSL ridges are normally not used unless a vaulted ceiling prohibits installation of struts to mid-span bearing points.
I think this reply might be better in the contractor forum, but here is my thinking anyway. We use LVL for there ease and straightness of the ridge.
as for splicing the ridge, why not when marking the ridge lay it out so the rafter covers the seam . then you install a collar tie under said seam?. there for eliminating the purpose of the post. Most offen the seams never fall over a bearing wall for the post to rest. there for the use of the LVL. Here on the Island its is not uncommon to have to set scaffolding up to set the ridge's up. being some are 14' height. its Just easier for us.
but probably does not pertain to his situation. BOB
like you stated on an older post building practices very from state to state.

Last edited by buletbob; 08-08-2008 at 08:38 AM.
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Old 08-08-2008, 08:52 AM   #5
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ridgebeams, need some help


Quote:
Originally Posted by buletbob View Post
I think this reply might be better in the contractor forum, but here is my thinking anyway. We use LVL for there ease and straightness of the ridge.
as for splicing the ridge, why not when marking the ridge lay it out so the rafter covers the seam . then you install a collar tie under said seam?. there for eliminating the purpose of the post. Most offen the seams never fall over a bearing wall for the post to rest. there for the use of the LVL. Here on the Island its is not uncommon to have to set scaffolding up to set the ridge's up. being some are 14' height. its Just easier for us.
but probably does not pertain to his situation. BOB
like you stated on an older post building practices very from state to state.
I can drive 3 hours from here and they frame homes completely different than they do here. Different regions definately have different methods. The code requires a ridge in a non-conventionally framed roof to be supported/sized as a beam if the pitch is 3/12 or less, which mandates the ends of the beam be supported by a nominal 4x thickness of bearing material with loads transferred down eventually to the foundation. I'm with Bob in that the collar tie under the splice would be similarly effective as a post in a steeper pitched roof. The newest I-codes have become much more tolerant and accepting of placement of collar ties, and I imagine that most inspectors might be reasonable in accepting that method. Ridge beams serve very little actual structural purpose in steeply pitched roofs...They simply facilitate attachment of the rafters.
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Old 08-08-2008, 09:17 AM   #6
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ridgebeams, need some help


Quote:
Originally Posted by thekctermite View Post
I can drive 3 hours from here and they frame homes completely different than they do here. Different regions definately have different methods. The code requires a ridge in a non-conventionally framed roof to be supported/sized as a beam if the pitch is 3/12 or less, which mandates the ends of the beam be supported by a nominal 4x thickness of bearing material with loads transferred down eventually to the foundation. I'm with Bob in that the collar tie under the splice would be similarly effective as a post in a steeper pitched roof. The newest I-codes have become much more tolerant and accepting of placement of collar ties, and I imagine that most inspectors might be reasonable in accepting that method. Ridge beams serve very little actual structural purpose in steeply pitched roofs...They simply facilitate attachment of the rafters.
AHHH!!! understood I thought those 3/12 pitches where then thing of the past. here 12/12 is very common. a few Thanks.

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