Thread: Truss plates

Anybody have any experience with these old gusset plates? House is 50 years old. The metal gusset plates seem to have a circular twist type of connector (about 1" in diameter) holding the two plates to the trusses, and nailing on one side. There are 3 circular twist connectors on these in the photo, but there are 5 areas available (two were not in use). Trusses seemed to have gaps or separation at the joints of the lumber.

Similar Threads:

• Electrical Cables contacting truss plates
• Truss joists
• cut truss
• Truss Uplift Info needed
• Bark Pocket in Truss

While I have not seen those types of truss plates before, the circular inserts remind me of the circular shear connectors used before truss plates when connecting wood to wood. A shallow circular groove was cut into each piece of wood to be attached together, a circular shear connector piece was installed into one of the circular grooves, the other piece of wood matched up to the shear connector, then a through bolt inserted through the hole in the center of the shear connector (oops, I forgot to mention that the shallow circular groove was cut centered around a through bolt hole).

Looks that those truss plates were adapting the shear connectors which went from wood to wood to go from wood to metal truss plate. Looks like the nails were mainly there to hold the metal truss plates on, the loads were transferred through the circular shear connectors - at least that is my guess.

Dear Chris;

These plates appear to have holes for a bolts, which are missing. Just from looking at the metal plates it appears there is not enough nails to handle the forces and the bolts appear to be missing. You mention their are gaps in the wood connections. I would recommend a professional engineer evaluate these connections.

I have not seen these plates before either, but they look sound so I wouldn't worry about them, especially after 50 years. Gaps at the joints should be expected due to wood shrinkage, and are not a concern if all the joints are as clean as those shown in your pictures. I wouldn't recommend any alterations as it could cause more harm than good.

Originally Posted by Richard Burkard

These plates appear to have holes for a bolts, which are missing.

Look at the second photo - the holes do not go all the way through, the holes are only through one plate, not the other. I doubt that any bolts were intended for those.

Just from looking at the metal plates it appears there is not enough nails to handle the forces and the bolts appear to be missing.

The nails are not there for strength of the connection, for the most part, if any part, the nails are there to hold the truss plates to the wood - at least in my opinion, and the transfer of loads is done through the shear connection pieces - those round pieces shown locked into the circular slots in the truss plates.

I'm with Thom, I see no reason for a structural engineer to address those plates.

OOppss. Sorry to have left the board for so long. I appreciate the feedback from you guys for your responses. Jerry, Richard and Thom I got a good sense of support from you and what looked to be an unknown and odd type of fastener to me - apparently is one of those long forgotten attempts at new methods of fastening trusses. Why isnt it still in use? and why have I never seen this before? after 10k inspections I've seen alot, but I know now and then there will be one more weird trick somebody is trying out.
Those old gusset plates were holding the roof framing together, no worries....just interesting to speculate why this kind of thing did not take - probably too much time and complicated steps to put this together vs the press on types of gusset plates.

Just saw another weird truss plate - gusset plates with one side with asbestos (it looks like asbestos) plates affixed to the metal. Why one side? Why even put this on the plate? If anybody knows about this, or want to take a stab....

Total stab in the dark: it almost looks like DIY from pieces cut out of duct work, hence coated on one side.

Originally Posted by Chris Weekly

Why isnt it still in use?

just interesting to speculate why this kind of thing did not take - probably too much time and complicated steps to put this together vs the press on types of gusset plates.

You got it.

Cost factor and time factor, the press on truss plates are less costly and quicker to install.

Just saw another weird truss plate - gusset plates with one side with asbestos (it looks like asbestos) plates affixed to the metal. Why one side? Why even put this on the plate? If anybody knows about this, or want to take a stab....

I have no idea, I've never seen those before ... are the asbestos/whatever sides facing the garage? (Just kidding - 'the fire side' you know. )

Mark - Total stab in the dark: it almost looks like DIY from pieces cut out of duct work, hence coated on one side.

Its really old stuff, and too regular of a square cut to be a home DIYer. Plus the metal appears to be 10 gauge - heavy stuff for the average Joe to cut with tin snips. Must of just been another attempt to see what works by another company getting in to the home construction, or truss fabricating biz. Still stumped at the asbestos on one side of the plates.

I like your idea Jerry. Got a good chuckle out of it. Heck, it might even be right!!!

Might the more recent home in question, and/or the earlier one, be of similar construction/appearance/size as the one you inquired about three years ago with the wood foundation crawl-space/floor truss system? (I recently "bumped" it with information and a link to another thread wherein I posted informtion on the truss design and construction type of same.

Material installed over plates at critical junction to maintain critical performance for a short time in fire event.

The metal plates would fail before the wood did in a fire. Gyp, plaster, other sheilds on same in past when mechanicals installed in attic or whole house fans, where ceiling below (membrane protection - gyp, plaster) for roof structure was compromised (suspect ridge vent is later ammendment. See often as detail for HUD or VA approval "back in the day". Did you indicate age of most recent home's photos? perhaps mid 60s to early 80s?

Clues in photos suggest water entry ridge vent (perhaps wind-driven rain?) Suspect ridge vent was not original, perhaps ammendment in re-roofing. Lack of insulation anywhere in attic space is concerning.

Originally Posted by H.G. Watson, Sr.

Might the more recent home in question, and/or the earlier one, be of similar construction/appearance/size as the one you inquired about three years ago with the wood foundation crawl-space/floor truss system? (I recently "bumped" it with information and a link to another thread wherein I posted informtion on the truss design and construction type of same.

Me -- No. All are different homes. That truss foundation though was a real piece of work. Just my particular run of luck to have weird truss configurations.

Material installed over plates at critical junction to maintain critical performance for a short time in fire event.

Me -- Maybe, just dont know why one side vs both sides.

The metal plates would fail before the wood did in a fire. Gyp, plaster, other sheilds on same in past when mechanicals installed in attic or whole house fans, where ceiling below (membrane protection - gyp, plaster) for roof structure was compromised (suspect ridge vent is later ammendment. See often as detail for HUD or VA approval "back in the day". Did you indicate age of most recent home's photos? perhaps mid 60s to early 80s?

Me -- 1960's for sure on the twist-on connectors; and 1972 for the asbestos plates

Clues in photos suggest water entry ridge vent (perhaps wind-driven rain?) Suspect ridge vent was not original, perhaps ammendment in re-roofing. Lack of insulation anywhere in attic space is concerning.

Yep, got that . Thanks HG for your observations.

I don't think the plates are gussets. A lot of people use all types of materials to serve as truss plates. We have all seen them at one time or another, such as wood, ducts, cut-out tin sheets etc.... This is just some other material the guy probably found and used. The bottom line is, as an inspector, I ask the question "does it serve the purpose?"

I do have a question of my own. Here in Canada, (northern ontario) the truss plates that a worker just hammer's on are illegal and the plates that are supposed to be used are, in my opinion not very good. They are about 1/8 inch thick are 3" wide by maybe 6" long, bassically the same size as the gussets people have been using for years. these plates have 32 holes for nailing but this is where I don't feel confortable. A person cannot put many screws without compromising the 2 X 4 rafters and not having enough screws will not strenghtened the splices as they should. I can sure use some feedback here guys, the city inspectors I spoke to are basing they're ruling on codes, "That's what the book sais to use, that is what you use", and I'm one-of-those where "if it don't feel right" there as to be more to it.

Gilbert,

Trusses are engineered products and must be designed by an engineer. The joints are a part of that engineered product and must be constructed according to the design. Connection plates must be of recognized materials and construction methods, or be of materials and methods from an approved ICC ESR (International Code Council Evaluation Services Report). This is covered under Section R802.10 of "the book" (The International Residential Code). All truss joints and connections must be evaluated based on the stresses/loads in the joint, also taking into account end and edge distances and spacing of the individual fasteners. However, what is "acceptable" depends on the competency of the local contractors and AHJ.

Is the fibrous material present to prevent the fastener from bouncing and ricocheting (off the metal plate) when it is being driven from a pneumatic (assumed) driver? It appears the fasteners are placed randomly and not installed in a rigid pattern.

Must trusses be designed by an engineer?......back in the day we built our own trusses when needed......nothing bad happened.

Thanks Thom. In just one paragraph you were able to answer any and all questions. Basically, when faced with contradictions and/or problems use common sense. People can still build they're own trusses (or anything else for that matter) as long as they know it's intended purpose and when in doubt call someone who knows. All inspectors know when they look at the different house components if they were installed by competent workers or not. Thanks....

Originally Posted by Ray Thornburg

Must trusses be designed by an engineer?......back in the day we built our own trusses when needed......nothing bad happened.

UL Listed Lighting Systems for installation into disco lighted floor and ceilings?

Not back in the day I designed, helped construct and install those floor and ceiling systems in discos ... nothing bad happened to any of those either.

BUT ... something bad did happen to some in, I believe it was New York City ... a fire started and when the plastic used for the floor system translucent (and clear) panels with the lights below started heating up and smoldering, the toxic gases given off cause, as I recall, several deaths.

Fortunately, discos, like the clubs of today, were always remodeling and replacing their 'stuff' with the newest and latest stuff, which means that all the floor and ceiling systems I designed and help construct and install were all removed and replaced with different fads ... so I no longer had to worry about anything bad happening because of those systems.

Just because something bad did not happen "back in the day" does not in any way mean it was okay or that something bad will not happen at some time in the future.

Originally Posted by Chris Weekly

Anybody have any experience with these old gusset plates? House is 50 years old. The metal gusset plates seem to have a circular twist type of connector (about 1" in diameter) holding the two plates to the trusses, and nailing on one side. There are 3 circular twist connectors on these in the photo, but there are 5 areas available (two were not in use). Trusses seemed to have gaps or separation at the joints of the lumber.

Like the others, I've never seen this type of gusset, but it almost looks like those are knock-outs; perhaps designed for through-bolts. Even stranger, when you look closely (200%) at these metal parts there are 'no nails' in the holes. In-fact, it doesn't even appear to have any type of fastener connecting the metal plate to the wood truss parts. The raised parts appear to be "bumps" in the metal, not fastener heads.

Although unrelated, The Kangaroo Island Council (Australia) published an article 04/23/2008 in "The Islander", in which they reported that toothed-nail connectors (truss nail plates) were failing, and some roofs had collapsed causing death. Their finding showed that certain toothed-nail connectors were "working their way loose over time." The time frame they identified was between 1970 through 1997 (a particular type of nail plate was no longer manufactured after 1997). But that's 27 years of buildings with potentially dangerous roofs.
Kangaroo Island Council - Potential Roof Truss Failure
(I apologize if this has been discussed here before, I just now read about it, and thought I would add it to the discussion.)

I still think it is a design of the split ring and shear plate combined into a truss plate connector. And the photos show that many of the split rings were not installed.

Those are, I think, an older version of something like this, with the steel truss plate acting as the shear with the split rings notched to fit the metal truss plate slots:
- Split Rings & Shear Plates
- http://www.g-lumber.com/pdf/HeavyConnections.pdf
- http://www.most.gov.mm/techuni/media/CE_05012_9.pdf
- http://www.timber.net.au/images/down...nt_design3.pdf

Here is another truss failure site: Donan Engineering :: Trusses and Truss Failures

Originally Posted by Chris Weekly

OOppss. Sorry to have left the board for so long. I appreciate the feedback from you guys for your responses. Jerry, Richard and Thom I got a good sense of support from you and what looked to be an unknown and odd type of fastener to me - apparently is one of those long forgotten attempts at new methods of fastening trusses. Why isnt it still in use? and why have I never seen this before? after 10k inspections I've seen alot, but I know now and then there will be one more weird trick somebody is trying out.
Those old gusset plates were holding the roof framing together, no worries....just interesting to speculate why this kind of thing did not take - probably too much time and complicated steps to put this together vs the press on types of gusset plates.

Just saw another weird truss plate - gusset plates with one side with asbestos (it looks like asbestos) plates affixed to the metal. Why one side? Why even put this on the plate? If anybody knows about this, or want to take a stab....

Replying to an old thread. The purpose of the fiberboard type material on those truss plates was to provide room for the nails to "mushroom" out. The nails were driven in against a steel backing plate and then the nails distorted to trap the plate below the fiberboard in place.

Originally Posted by Mark Reinmiller

Replying to an old thread. The purpose of the fiberboard type material on those truss plates was to provide room for the nails to "mushroom" out. The nails were driven in against a steel backing plate and then the nails distorted to trap the plate below the fiberboard in place.

Thanks for keeping up with this Mark. It sounds like you have seen this before and may know some its history. I think Franz was also onto the right track back in post # 14.
Well this truss method is history now and standards certainly have changed as Thom the engineer has stated in his post. Thanks all for your on-going interest. We get a sense of the progression of framing and construction when looking at what methods were used back in the day and how it was improved to modern day standards. Like JP said earlier " Just because something bad did not happen "back in the day" does not in any way mean it was okay or that something bad will not happen at some time in the future."