maximum joist spacing, at each end and 4" o.c. Connect with a cluster of 30-10d common nails (0.148" dia.), for a 55 psf total load at 16" o.c. Jack up the joists so that the new joist bottom side matches the cut joist bottom side. Personally, if it was my house given what I paid for it, I would remove the pipes and ducts to nail new joists (of the required grade and spanning from inside of bearing to inside of bearing) to one face of the cut joists. If i understand things correctly, I would expect the slope to be more or less centered RE: Fixing a 2x10 floor joist Stillerz (Structural) 10 Dec 09 09:05 I'm curious how the cut is in the middle but the slope is within 4 foot of the corner. (4 or 6 bolts each side of the cut or 8 to 12 bolts total on each 8 ft piece that is scabbed in place) I would start with 2 or 3 bolts at each end of the 4 foot distance of joist piece that is on each side of the cut. A similar connection would be needed on each side of the crack. The 8 ft pieces that are in place now MIGHT be sufficient IF they can be attached to the original joist in a manner that is sufficient to develop the bending moment that is present. MAYBE this can be accomplished with by jacking the joist up prior to installation of the strap. In addition, especially for the metal strap, I would think some form of "pre-tensioning" or other "pre-loading" to get the tension into the strap will be needed. Haven't done the calculation but just guessing. It seems that nailing a 2x4 or a steel strap to the bottom of a joist will be difficult to do so enough to achieve sufficient shear transfer. RE: Fixing a 2x10 floor joist racookpe1978 (Nuclear) 9 Dec 09 22:09 If option a), should I calculate my nail spacing such that the inverted "T" beam would have the same amount of deflection as a comparable 2x10 based on L/360? Would I need to add a 2x4 over the entire length (16ft)? Or how can I calculate the necessary length required for the 2x4? Would it be as easy as just decreasing the nail spacing by half if I would use an 8 ft long 2x4 as long as I am not splitting the 2x4?
Now I would like to repair it - appropriately.Ī) lift the joists (using a jack) one by one the appropriate amount and nail a 2x4 to the "notched" 16' long 2x10's from the bottom? (To make an inverted "T" beam)ī) lift the joists, slide in new continuous joists and remove the "old" ones? That would be rather involved since gas and electrical lines are going through the joists. Obviously not a good solution.Īnd shame on me for not noticing 4 years ago.
The builder "fixed" it by nailing one 8 foot long 2x10 next to each of those. Taking a closer look in the basement under this room, I noticed that 3 floor joists (16 feet long) have a cut in the center about half way through (on the under side). Well, only difference being instead of a generally cosmetic nail pop in a drywall issue, loose truss plates is a structural issue.While renovating a room in my 4 year old house I noticed that the floor has a slope of about 1" within 4' in one corner. Just doesn’t make sense for the plate to bow out from the center so smoothly when run over with a roller, unless there is some other method of truss assembly I’m not aware of? Moisture and heat makes more sense…I mean why do new construction have nail pops all the time? Cause the house settles, wood dries and gets wet again, HVAC gets turned on and dries framing, framing gets loaded, gaps/etc between framing members get compressed/open up, and so on. Think about it, trusses are pieced together on a flat platform, gusset plates are put over joints, then comes a roller(think steamroller but much smaller and longer) runs over the plates and voila its all connected together and the truss is done. Overall, I think it’s less of a manufacture/assembly issue than issues with the plate, wood, and the environment the trusses are in. I often see a short 2x4 scab nailed on that really doesn’t do much to reinforce the joint, a single framing nail is used to hold the members together with loose plates, or some other really inadequate reinforcement applied when framers attempt to repair loose truss joints/plates or damage during construction, or just hide it long enough from city inspectors to pass the framing inspection. Even the worst framer isn’t blind enough to let a large loose joint stand like this when built, so I believe this is something that gradually happened over time. I don’t think this truss was actually installed at the house with this splice joint loose. The bowed gusset plate and loose teeth that is present before the top truss chord twisted and busted the splice joint loose. This is what I’m referring to and I see way too often. See this enlarged picture from one of Kevin’s original pictures.
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