Hang floor joists on beams or run them over the top?
joenorm
| Posted in General Questions on
Hello.
I will be laying my joists on top of the sil plate and using a rim board around the perimeter wall.
I have two beams running wall to wall inside the foundation that the joists can either hang off of, or run over the top, depending on what heat I put the beams.
The downside to running over the top is it gives less head room in this part of the crawl space making access a little harder. But this method would require less hangers and better insulation.
Hanging them on the beam gives the extra headroom but makes for thermal sinks where those beams contact the subfloor.
Any thoughts?
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Replies
Some of it depends a little on what type of materials you are using. If using I-joists, run as long a joist as possible on top of the beam: you'll get a stiffer floor. You'll also get a slightly stiffer floor with conventional lumber by overlapping over beam. You'll get even shrinkage by running over beam if you are using a LVL type beam. Running conventional joists into an LVL beam may cause some uneven shrinkage. A lot easier to run branch ductwork in the joist space with drop beam.
If it's just affecting the clearance in the crawl space, which isn't going to be accessed very often, then I'd go for running the joists over the top of the beam for the stiffer floor, fewer hangers, and better insulating ability.
If you were looking to raise the beam up to gain clearance in an OCCUPIED space, then I'd prioritize the headroom in the occupied space over the other issues.
You won't be in that crawl space very much. Most people try to avoid working in crawl spaces as much as possible. Do a neat job on the mechanicals to minimize your chances of needing to do maintenance in there, and install a decent amount of lighting (code minimums is NOT a "decent amount") to make future work easier. Painting the bottom edge of the beam and an inch or two up each side with bright orange paint can help to minimize bonked head pain later.
Bill
Hi Joe,
I think you have your answer. The flush beam is typically used when trying to create headroom and/or a flat ceiling, less of issues in a crawl space than in a living space. Otherwise the drop beam is advantageous for numerous reasons, as you and Joel noted.