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engineered/laminated wood joist specifications

engineered/laminated wood joist specifications

engineered/laminated wood joist specifications

(OP)
I am attempting to draw my dream home in 3d using a CAD software and intend to use laminated beams/joists to span a 52'4"x20' wide sub-basement and an adjacent 58'x30'wide  main basement.
To make use of the joist space for HVAC / piping I am thinking 16" deep laminated joists and was wondering what their span-ability is and their on-center separation.  Also, is a 16" depth lam-beam actually 16" or is there some industry difference allowing for sub-floor materials etc (e.g. 2x4)

The home is a 4 split level home designed to reduce the overall height above grade with the main basement including a garage at grade on one side .

RE: engineered/laminated wood joist specifications

For the HVAC layout contact your HVAC contractor for requirements.  

For the span-abilty and OC seperation, contact a local lumberyard / truss shop and let them help you workout the most cost effective system.  Consider open wed floor joists.

RE: engineered/laminated wood joist specifications

(OP)
Last time I checked there weren't any lumber shops that would generate a joist or truss or any other plan unless they were getting paid.
This is just an experiment with drawing in 3d and I was hoping that someone knew where I could get a laminated beam spec sheet that would provide a table of spans supported for each width/depth combination and at what recommended OC distance.

what's an open wed?
I've heard of open web, but that doesn't sound like something that would support a lot of weight at more than 16" separation.  Using the 16" depth, I was hoping to get away with 24" OC

RE: engineered/laminated wood joist specifications

If you dont want to try discussing you design with a truss shop for free, consider hiring a proffesional engineers to do the layout and design.

RE: engineered/laminated wood joist specifications

GLULAM and Weyerhauser both have websites. start the search there.

Richard A. Cornelius, P.E.
WWW.amlinereast.com

RE: engineered/laminated wood joist specifications

(OP)
I found some good information from a few sites for the 20' span, and ended up using a 24" oc for a 16" deep joist with 2x6 chord and 1-1/2 web
However, I have become a victim of information overload for the adjacent space that has a ~30' span.  I would like to avoid putting in columns and did see at least one spec for an 18" deep i-joist, but the differences between a simple vs multiple or even a continuous span were never spelled out, so I wouldn't know how to draw it without seeing it explained.
Although, the acrobat files I have found have been for stock joists, I imagine these i-joists could be custom made.
For now I went with an 18" deep i-joist with sim chord and web on a 16" oc.

RE: engineered/laminated wood joist specifications

Be careful as your spans get longer your supports get significantly larger loads.  The walls may not be able to support the loads.  Get a structural engineer involved early in the process and you will find that it will save you lots of grief.  If you aren't experienced in structural matters all the complex intricacies of having load path to ground get lost.  A mechanical engineer who is a friend of mine built a house.  He made sure he supported his ridge with a post but left the post unsupported below the second floor.  He came to me when he came back after a large storm and found his floor had sagged 2" in the center under the post.  It was much harder to fix after the fact than if I had looked at it before he built it.

RE: engineered/laminated wood joist specifications

(OP)
OK, it looks like its time to provide some more details on my dream home design.
It is a 4 level split level home, but only two levels are stacked on each other as the split puts the two halves of the house offset at half each level's height.
So the '2nd' level (bedrooms) sits on top of the main basement (garage/laundry/family room) and the '1st' level (kitchen/dining/LR) sits on top of the sub-basement (electrical/utility/computer servers/storm safety).  
With the exception of the sub-basement the other levels will be on sloped ground so all have at-grade egress.  
That said, there should be very little load problems, but then that's why I am here, just to make sure.
I mean if I have to, I'll put a row of 8" lally columns down the middle of my basement and install a mid-span beam for the the joists to sit on.  Course that means I can go to a shallower joist, but I'll probably have to beef up the slab underneath.
also, the location of the house will be at least below 40° latitude, preferable below 35°, so there won't be a need for a steep roof either.

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