Strange Wood Framing | Concerns
Strange Wood Framing | Concerns
(OP)
See attached photo. I was looking at this building for something unrelated to the framing shown.
The photo is of roof framing: 3x10s @ 16" o.c., spans around about 15ft. from walls to center steel beams. To pitch the roof the original builder built a series of 2x4 stilts off the framing which in turn support flat 2x4 (@16 o.c.) to support the pitched sheathing. These 2x4 posts vary from 0" to about 12" in height. The building is a two story brick masonry residential, late 1800s but the framing shown is obviously much newer (1990s).
My work was not related to this framing so I am wondering what kind, if any, of upgrades to the framing I should recommend - or should I leave well enough alone? The joists are obviously not braced by the sheathing. There also is an issue of the diaphragm not being connected to anything. Since this is an existing condition I don't want to go overboard and recommend major fixes if they are avoidable. I was thinking of solid blocking between the joists, providing post installed ties from masonry to the joists, and was also considering some diagonal struts up from the blocking to provide a lateral path for the diaphragm. The roof/roofing is not being worked on so ideally all work is from below and does not penetrate the roof. Any thoughts/recommendations?
The photo is of roof framing: 3x10s @ 16" o.c., spans around about 15ft. from walls to center steel beams. To pitch the roof the original builder built a series of 2x4 stilts off the framing which in turn support flat 2x4 (@16 o.c.) to support the pitched sheathing. These 2x4 posts vary from 0" to about 12" in height. The building is a two story brick masonry residential, late 1800s but the framing shown is obviously much newer (1990s).
My work was not related to this framing so I am wondering what kind, if any, of upgrades to the framing I should recommend - or should I leave well enough alone? The joists are obviously not braced by the sheathing. There also is an issue of the diaphragm not being connected to anything. Since this is an existing condition I don't want to go overboard and recommend major fixes if they are avoidable. I was thinking of solid blocking between the joists, providing post installed ties from masonry to the joists, and was also considering some diagonal struts up from the blocking to provide a lateral path for the diaphragm. The roof/roofing is not being worked on so ideally all work is from below and does not penetrate the roof. Any thoughts/recommendations?






RE: Strange Wood Framing | Concerns
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RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
Mike McCann
MMC Engineering
RE: Strange Wood Framing | Concerns
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RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
Okay, replacing them individually would be kind of a pain, but maybe installing them that way in the first place was less so.
E.g., maybe the joists and stilts were installed to replace some prior support system, maybe a truss, without severely disturbing the purlins or the actual roof.
The stilts are short enough to be sort of self-bracing if they are cut square, and they could be used to adjust the local roof pitch by cutting them a hair oversize and hammering them into place.
In short, I think that we are looking at a specific solution to a specific problem, but we don't know what the problem was. There must be an interesting story there.
Before sending up a flare, I'd chat up the older or former tenants of the building, as informally as possible of course, and check with the AHJ for stored permits and plans. Okay, that last is a long shot, but somebody somewhere must get permits, once in a while, right?
Mike Halloran
Pembroke Pines, FL, USA
RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
Are you in a high wind area? Would uplift be a concern?
RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
I've learned to refrain from telling a residential builder, "that won't work", as he will have likely seen such a configuration "work" many times in the past and I then loose credibility with him. (Of course, for him "work" means that it hold together long enough to get the structure built, not hold up under full design load.) In any case, now I try to remember to say things like, "well, in order to fully brace it..."
RE: Strange Wood Framing | Concerns
I am thinking that I'll anchor the parallel joists to the wall, specify solid blocking @6ft o.c., and provide some diag 2x4 struts up from the new blocking to the 2x4 posts and purlins and call it day.
RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
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RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
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RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
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RE: Strange Wood Framing | Concerns
RE: Strange Wood Framing | Concerns
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RE: Strange Wood Framing | Concerns