Q:We are replacing a beam in an old ceiling/floor assembly. Some of the rough-sawn joists are a full 2 inches thick, others 3 inches, and these thicknesses vary plus or minus up to 1/4 inch. In one area, the joist ends are also notched for a ledger board. What would you recommend for hardware, since regular joist hangers won’t work?
A:Jake Lewandowski of Great Lakes Builders, a Chicago-based structural repair contractor, responds: Good question. We have encountered this type of scenario on numerous projects, and there are a number of ways to deal with it. Keep in mind that any solution we come up with, we always run by an engineer first.
A common problem we see is a large, heavy timber girder beam (we refer to this as a “beam line” in our area) with a small, continuous 2x2 board nailed along the side of the beam at the bottom. The joists were notched to sit on top of the 2x2 and the joist ends were toenailed into the timber beam. Regularly, we see the 2x2 missing (torn out somewhere along the way) or rotating and, typically, a horizontal crack right at the notch on the joist.
To correct for this when you are replacing the existing beam, you might consider increasing the width of the new beam. For example, if the plans show a three-ply LVL beam, you could make it four or five plies. Doing this often allows you to reduce the beam depth (explore options with an engineer), and I would consider that if a shallower beam is a benefit. Hopefully, then you would be able to cut the notches out of the joists, which would be ideal.
The easiest (though not my favorite) solution is to add solid blocking between the joists, fastening it to the beam with some sort of structural fasteners. Then you would install joist hangers, using 2 1/2-inch SDS screws for the hangers. You want the fasteners to go through your blocking and into the timber.
My preferred repair is to infill the notch with a fitted block and then install Simpson HTU hangers (made for trusses), which have an elongated heel. Unfortunately, this solution is not always possible due to the increased thickness of the joists.
In cases where I have a full 2-inch joist, I will install the fitted block to infill the notch. Then I will fasten a 1/2-inch plywood block full joist height on each side of the joist to make it a full 3 inches. We can then use a double 2-by hanger. Or we can make it 3 1/2 inches to accept a double LVL hanger. The width of the plywood can vary to accommodate variations in joist width.
If no notch is present, or you’re looking to install a flush-mount beam, or you have a ledger connection and your joists are irregular in width, the ideal solution is to have Simpson Strong-Tie bend a hanger to your width specifications. The downside is there are only a handful of hangers that you can select from, and it can take weeks or more to get them. As an alternative, I would look for rough-lumber hangers, which have an “R” at the end of the SCU number for “rough lumber” and are a true 2 inches wide. There’s always the single-ply LVL hanger option, as well, which is just over 1 3/4 inches wide. If the available hanger options don’t fit exactly, choose one that’s wider and pack it out with plywood running the full height of the joist. For example, for a 2 1/4-inch-thick joist, we would use an LUS28-2 (which is 3 inches wide and made for carrying double members at nominal 2-by dimensions) and add a full-joist-height piece of 3/8‑inch plywood on both sides of the joist.
