We've got folks here from every profession and trade.
They're building 3-story apartments next door. With lumber. It piqued my curiosity. How tall can you make a building out of lumber before it is either {a} structurally unsound or {b} cheaper to use another construction technique?
I'm sure someone here knows.
There are a lot of variables in that question. Structure use, apartments, retail, office space, etc. Also location with regards to wind loads, seismic loads and local building codes. Typically the highest you would usually go would be 3 stories, but depending on the design and market may be able to go higher.
A 6"x12' 16-gage metal stud is about $19 each. A 2x6x12' wood stud is about $7. That makes a big difference to a developer.
I'm designing a 4-story hotel right now in wood stud bearing wall with I-joists. All the bearing walls, which includes the walls between rooms, will be 2x6 wood studs at 16" oc. The ground floor will be double 2x6s at 16" oc.
It's cheaper to build the whole thing out of wood even though it effectively means that every interior wall and floor must have a 1-hour fire rating because it is combustible materials.
Five stories of wood over a concrete "podium" floor is not uncommon here in Atlanta.
Like Duke said, it's economic. But that many stories means a crapload of ganged studs in the load bearing walls to transfer all that weight and wind load down to the foundation. (Again, like Duke said
).
The ones I can't look at are the cantilevered wood balconies. These same cheapskates that used wood instead of steel use paper thin waterproofing and lousy detailing.
It's a game of musical chairs.. a trap for the sucker that owns it after the first four years.
In answer to the original question - structurally, you can go pretty high with wood framing, but effectively, 4 stories is the maximum. After that, it becomes a mid-rise building and a whole bunch of other code requirements kick in that either make wood prohibitive or not allowed at all.
Article on NPR yesterday about some new wood products that are allowing for much taller wood structures. Currently the one they are building is 148'.
This is going to engineered timber products though, not your usual studs and plywood.
OHSCrifle wrote: Five stories of wood over a concrete "podium" floor is not uncommon here in Atlanta.
Here in Delaware, too.
OHSCrifle wrote: The ones I can't look at are the cantilevered wood balconies. These same cheapskates that used wood instead of steel use paper thin waterproofing and lousy detailing. It's a game of musical chairs.. a trap for the sucker that owns it after the first four years.
There was a truly scary set of early-'90s condos around here that had tons of balconies and screen walls hanging off the side of the all-wood buildings. I used to drive by them a lot and over the years you could watch the balconies sag. And that was before the big postmodern pediment-screenwall-things started parting company with the rest of the building.
KyAllroad wrote: Article on NPR yesterday about some new wood products that are allowing for much taller wood structures. Currently the one they are building is 148'. This is going to engineered timber products though, not your usual studs and plywood.
I heard that as well, it was an interesting story.
This office building was recently constructed in downtown Minneapolis: https://structurecraft.com/projects/t3-minneapolis It uses large wood timbers, much like how they used to build buildings 100 years ago.
I see a lot of 4 or 5 story apartments around here built with dimensional lumber. However, the lumber for the exterior walls apparently has to be specially rated for that purpose - there was one apartment building here last year where the inspector found the lumber in the exterior walls didn't have the proper stamps, and the contractor had to tear the whole place down and start over.
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