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Thread: 2x4 main beam ?
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01-04-2013, 07:51 PM #1
2x4 main beam ?
Inspecting house today that was built in 2004 and I found an issue with the main beam (girder). The floor joist were supported with pressure treated 2x4's, has anyone ever seen this type of application ?? (I havent in my 7 yrs. of inspecting. Any advice would be appreciated.
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01-04-2013, 08:13 PM #2
Re: 2x4 main beam ?
The 2 X 4 in this case is not a beam. It is the top plate of a stud wall. Notice that the studs are lined up with the joists.
That stud wall support on a concrete footing is very common in crawlspaces here.
The addition of the 2 X 4 on edge is a bit unconventional. Usually the wall is constructed with a double top plate. And sometime diagonal bracing is needed. Sometimes plywood is nailed to one side of the wall. But the basic concept is OK. I can't speak for whether it needs more nails or bracing without more info.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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01-04-2013, 08:40 PM #3
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01-04-2013, 09:24 PM #4
Re: 2x4 main beam ?
Single top plates are allowed ... provided certain conditions are met.
- R602.3.2 Top plate.
- - Wood stud walls shall be capped with a double top plate installed to provide overlapping at corners and intersections with bearing partitions. End joints in top plates shall be offset at least 24 inches (610 mm). Joints in plates need not occur over studs. Plates shall be not less than 2-inches (51 mm) nominal thickness and have a width at least equal to the width of the studs.
- - - Exception: A single top plate may be installed in stud walls, provided the plate is adequately tied at joints, corners and intersecting walls by a minimum 3-inch by 6-inch by a 0.036-inch-thick (76 mm by 152 mm by 0.914 mm) galvanized steel plate that is nailed to each wall or segment of wall by six 8d nails on each side, provided the rafters or joists are centered over the studs with a tolerance of no more than 1 inch (25 mm). The top plate may be omitted over lintels that are adequately tied to adjacent wall sections with steel plates or equivalent as previously described.
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01-04-2013, 09:57 PM #5
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01-05-2013, 11:50 AM #6
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01-05-2013, 11:53 AM #7
Re: 2x4 main beam ?
I would say 'Yes, it applies to that too.'
This is new to me, I haven't seen this in my area at all.
We've got some stupid contractors, but they are probably too smart to do something that stupid - even though they would be allowed to, it would take too much planning to execute it properly and would, in the end, likely not really save them any money.
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01-05-2013, 04:34 PM #8
Re: 2x4 main beam ?
As Jerry said, it can be done. The practice isn't typical. You will find this (no tie plate, only top plate) to a degree throughout the framing of energy efficient (green) built construction. Less wood taking up space, better overall R value walls. Also less use of natural resources. Use metal connectors in place of tie plates. Unfortunately you also see it in just plane cheep building. Trying to use the least amount of material to meet code. Were the nail patterns correct? Or just 8d's toe nailed to the face of the studs. If it was treated lumber used were the type of nails used correct for this application. Were there anchor bolts used? I didn't see any in the photo's. It looks as though there is a pass through area in the wall without a header. The 2x4 which was on the face of the top of the wall, was probably tacked in place to use as (a tie plate) something to hold the wall together until it was fastened together with the floor joist. At this point I can't see it serving any structural purpose. I don't see any roll over blocking between floor joist.
Looking further at your photos (the last 2). It appears the top plate does not extend to the sill plate on the exterior wall. Do you get tremors in Tennessee?
Last edited by Mark Hagenlock; 01-05-2013 at 04:45 PM. Reason: incomplete
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01-06-2013, 09:03 AM #9
Re: 2x4 main beam ?
If that is a one- two- family site-built dwelling (however I suspect it is a HUD manufactured home set upon a block crawl foundation):
No it is NOT ALLOWED.
There IS NO BEAM.
This is NOT advanced framing simply of an intermediate joist support wall of continuous joists. This is a bearing wall with joist ENDS and is NOT properly executed ADVANCED framing. First BOTH joist ends must bear completely upon studs when the second (doubled) top plate is omitted.
Thus without those studs having been doubled up so as to be alined with BOTH of the meeting/staggered floor joists - the top plate MUST be doubled. The wall studs may NOT be of a lesser dimension than the plate - in advanced framing the load distribution must be exactly as prescribed.
Sawn lumber is NOT TIMBER. There is no beam present. The "stick" framing is incorrect.
The joist ends are not blocked they further are subject to spreading, roll-over, etc. are merely compressed.
Next - the top plate is x6, the "framer" cheated using a 2x4" long aside with a second 2x4 on its end to "capture" and fill in the shorted depth lacking from the wall's studs and as incorrect application of lateral stability, shear, etc. it further is merely "face nailed".
There are other concerns regarding the LACK of a floor plate - which was apparently meant (IF present) as the top of a site-built box beam.
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01-07-2013, 10:31 AM #10
Re: 2x4 main beam ?
This support system needs to comply with the requirements for an interior bearing wall per IRC Section R602.4 (which refers to R602.3). As such it must be sheathed (R602.3), wall constructed and joists anchored per Table R602.3(1) and/or (2), the joists must be centered over the studs (R602.3.2, exception), single top plate strapped (R602.3.2, exception), mudsill anchored to the foundation (R403.1.6), and the joists must be laterally supported (R502.7).
Thom Huggett, PE, SE, CBO
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01-07-2013, 11:24 AM #11
Re: 2x4 main beam ?
Am I the only one concerned with the bare copper water supply lines, not insulated in a crawl space (at times, probably) subject to freezing temperatures?
Comments, my dear Watson?
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01-07-2013, 01:11 PM #12
Re: 2x4 main beam ?
For one, because you are making assumptions that the distribution potable is subject to freezing. Frankly I'd be more concerned about the waste line parallel alongside the rim than that of a crawl containing HVAC system componants.
We have nothing to sugest that the crawl is open (I doubt that it is), nor that the foundation walls, rim, etc. are not insulated from the exterior (doubt as well, but not impossible), nor that the area isn't heated or otherwise controlled so as to prevent freezing temperatures from occuring therein.
The moisture at the lower half of the block wall, and what can & cannot be "seen" regarding elevation, exposed earth near wall, and black mat covering ?? are merely observations which may or may not be clues to what the OP chose NOT to share. The OP indicates the studs themselves are PT although we see no identifying marks in the photos.
As I mentioned in my first reply, I suspect from the appearance, that the crawl foundation is possibly supporting a HUD manufactured home , modular, (or for that matter, a home section having been "set upon" the foundation or "raised up/jacked up" for any reason - such as to effect joist replacement, to replace piers and BEAM, to build the block wall crawlspace foundation - replacing other system- , etc.) and that the pictured appears to be not more than a temporary brace/support while a more correct and permanent support was to have been constructed/re-constructed and put into place (and the existing pounded out from the 2x4 "cheater" nailed to the undersized "studs" wedged under the single 2x6 "plate" as the bond beam foundation is/was "off" regarding the joist ends the bearing support wall was/is to support.
The OP hasn't responded or indicated either way (HUD Mfg home, modular, or "stick built" (stick built/site-built is doubtful).
As this is in the Technical area, structural section, why is sticking with the OP's (as an HI!) topical concern/question a concern or problem for you?
As an HI the poster doesn't require instruction from an engineer as to how and what to inspect the plumbing, the insulation, or determine the 'subject to freezing - or not' status of the system componants in subject crawl space! Such is well beyond the solicited information requested.
Not sure why YOU felt the need to individually target, solicit and cross post OFF-TOPIC banter with your saracastic "my dear" non-endearing B.S.
Last edited by H.G. Watson, Sr.; 01-07-2013 at 01:24 PM.
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01-07-2013, 01:31 PM #13
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01-07-2013, 07:55 PM #14
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01-08-2013, 06:45 AM #15
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01-08-2013, 08:22 AM #16
Re: 2x4 main beam ?
I assume his location in California requires seismic over-building of the support wall.
No sheathing is required here, but a double top plate is standard. In my mind, that is the shortcoming in the OP's pics. The 2X4 on edge appears to be an add-on, and I am wondering if it was called for by a building official as an upgrade.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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01-08-2013, 11:42 AM #17
Re: 2x4 main beam ?
The wall is not properly constructed, un-restrained at wall ends or openings, braced, blocked, nor laterally restained to sustain/support a ribbon
Look carefully at the top right of this photo - note the voids at the right end of the wall plate and the void adjacent where insulation is not present see the void and see the sill plate upon the block wall. Note voids at the area above.
Not an intermediate bearing wall as joists are not continuous, is an interior bearing wall (supporting joist ends) must be built as exterior bearing.
Look carefully at this next photo - missing entirely a stud anywhere near joist at opening in wall (where the cable drapped across the bottom plate) to the left of the second stud from the right in photo, obviously for access no jacks, no header, no box beam, no girder
The exterior are six block courses. The weeping/moisture suggests reinforcement btn 3rd & 4th course, not bond beam in 6th course. Overall
Interior bearing wall (not intermediate) appears to be upon grouted or poured bond beam at first course exterior wall block, Making the framed wall/crib wall at least five courses high plus the 2x top plate (at least 42"-ish). May or may not be redesignated 1st story.
We do not have the specifics, can only go by what we have pictured.
The joist ends are lapped, not spliced.
R502.6 Bearing. The ends of each joist, beam or girder shall have not less than 1.5 inches (38 mm) of bearing on wood or metal and not less than 3 inches (76 mm) on masonry or concrete except where supported on a 1-inch-by-4-inch (25.4 mm by 102 mm) ribbon strip and nailed to the adjacent stud or by the use of approved joist hangers.
The (lapped) joist ends are not laterally restrained at interior bearing wall (502.7) note complete voids where potable & waste pipes pass above and voids at end of wall above wall plate between joist parallel to exterior wall (parallel to wall PVC present).
Requirements of both Ch. 5 & 6.
We do not know if crawl has been redesignated as 1st story, nor what is above same (for example, other than IRC construction, or if IRC construction - attic, brick veneer on stick framed exterior walls, block exterior walls...etc. etc.)
Bottom line, if IRC prescribed construction - required "things" are lacking from what can and cannot be seen and what we have and have not been told. We do not know the status of what lies beneath this wall or cripple wall, nor if it has been redesignated first story. Precisely what combination will accomplish, DEPENDS on the multitude of unknowns which we are not provided, including elevations, soils/seismic nor winds, etc. reinforcement, loads, etc. We do not know of engineering, or IF even IRC is or was applicable. As the OP has referred to as a "home" I think it is fair to assume that the platform floor system supports a sleeping room somewhere on or above it.
Last edited by H.G. Watson, Sr.; 01-08-2013 at 11:57 AM.
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01-08-2013, 03:13 PM #18
Re: 2x4 main beam ?
Bridgeman,
Erwin TN is in Eastern TN and while its in the mountains, its not likely to need insulation on the pipes in the crawlspace. At least they are not required to be insulated in the Knoxville area (an hour or so away).
As a side note, most of the manufactured homes around Knoxville area that were built around 2004 had I-joists for the floor framing.
Since Erwin is in an area where code enforcement is sketchy, I suspect the framer just made up stuff as he went along. There isn't much about it that's right IMHO.
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01-08-2013, 03:33 PM #19
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01-09-2013, 01:49 PM #20
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01-09-2013, 02:19 PM #21
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01-09-2013, 03:15 PM #22
Re: 2x4 main beam ?
Thanks for the feedback, Sam.
For your own info, where the stud is missing, this is often done, should be done for access, but they should have framed in a header, with jack studs under it, just like framing a doorway.
Some people mentioned the lapped joists as if this is a violation, when in fact that is standard procedure. Lack of blocking is not proven. There could be X-bracing, hidden by insulation. How often do you see 2 X10 or 2 X12 blocking between the joists? Maybe in a book.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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01-09-2013, 05:28 PM #23
Re: 2x4 main beam ?
Too funny. I do not agree, nope, no-way, no how, not for what you've described and photographed. You've not answered if plate, heck you copied both posts and just said it was single story above and truss roof, that's all ya said.
Shuda Coulda, wuda referenced '06, but IMO its still very wrong.
Doubt "the inspector" IS the B.O., but if same then guess shouldn't be surprised doesn't know better, it is east TN afterall.
John K.,
Its not that the joists are staggered which is a problem in and of itself, it is the lack of proper bearing and transfering of load of the first floor and attic above when using prescribed advanced framing for an interior bearing foundation wall.
Both joist ends must be supported and load transfered. A single plate the allowance is a mere inch with advanced framing (single top plate).
Originally Posted by exception
Last edited by H.G. Watson, Sr.; 01-09-2013 at 05:49 PM.
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01-09-2013, 10:35 PM #24
Re: 2x4 main beam ?
Agreed. The 2X4 on edge helps in a limited way. It looks like a bandaid that was added.
Here is a pic of a typical supporting wall, properly framed and secured to the footing with anchor bolts. For a taller wall, they will often go up to 2X6's for a few dollars more.
John Kogel, RHI, BC HI Lic #47455
www.allsafehome.ca
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01-09-2013, 10:42 PM #25
Re: 2x4 main beam ?
Yes the lack of blocking is not proven. It is conjecture based on the mechanical penetrations and the visual of the insulation batts, and the fact that we are dealing with a location in the floor framing were you would normally have roll over, or squash blocking. X - bracing, or bridging is generally found in the field. They are sold in pre-cut bundles. Based on joist depth and spacing of 14 1/2", or ( maybe) 22 1/2". You would have to individually cut all, to fit 13" space. Blocking goes in during floor framing. bridging goes in during floor framing, but doesn't finish till after floor deck is down.
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