So I accompanied a friend to see the new house she’s having built (don’t get me started on the idea of building an expensive house in this economic climate, that’s a whole 'nother issue). Anyway, the 2x4s being used are these crappy looking pieced together sections maybe a foot and a half long. What’s the name for this type of lumber?
I hadn’t seen these but I understand all the builders are using them nowdays and that some people (including Bob Vila) think they’re actually stronger than regular 2x4s. They really did look like rotten pieces of wood with lots of knots and tree edges and I can’t believe thay’d have the same strength of a better piece of wood.
Yeah, I’m less concerned about the glue (glulam is pretty well tested and strong as crap) than the quality of the wood. I’ve done structural calcs for wood and knots, etc. ding you for strength. Plus, some of these pieces didn’t even have a full cross section. Anyway, know what this lumber is called so I can google it?
Are you talking about smaller pieces of wood glued in between two full size pieces, or one piece being used to lengthen two other pieces. The latter is called a “scab”.
A general contractor friend of the family uses finger jointed studs whenever he can. I think the idea is that dimensional lumber is so bad nowadays that any sawn wood studs are likely to warp the walls. The sheathing sort of turns the whole wall into a series of box beams.
I’m not sure if I agree for load bearing walls–the inside is sheathed in drywall and the outside is almost always OSB which will fall apart if any water gets inside the envelope. I could see an advantage for interior walls since roofs are almost always truss-built nowadays and the interior walls should never see any loads.
In addition to finger-jointed, there are a few variants of oriented-strand techniques being used for dimensional lumber. In 4x8 foot sheets, it’s called OSB or oriented-strand board. I have no idea what it’s called in the form of a 2x4.
A similar material is called glu-lam, but that’s been primarily used for making 4x8 (or larger) material for beams and headers, and is made of long strips of wood, rather than small chips. One really neat thing about glu-lam is that exotic shapes such as large arches can be pre-fabricated at the plant.
The oriented-strand or finger-joined lumber looks horrible to those accustomed to long clear pieces of pine or fir, but it’s every bit as strong, and overall, better than traditional lumber as it enables a much higher usage of a tree, and it’s much less likely to exhibit the usual problems of lumber such as warps and twists.
If you happen to catch a rebroadcast of the This Old House episode that was shown on 11/3, they had a good, though short, discussion of the manufactured dimensional lumber that they are using. Studs as well as beams.