Floor/Roof Framing Plan...help

extremeregime · 发表于 2022-7-7 18:51:55

Hey there,

I hoping I could get some help please and thanks.  I am working on a Floor and Roof Framing plan for my design class.  Doing a mixed use builing...retail and residetial.  However; I feel that I am stuck or doing this all wrong.  All I've done is been putting in my headers over the doors, and next I am planning on putting in my alpha joists.

However, I am unsure of a few things.

1) Was is the depth of an aplha joist?  Is it your regular joist 2x size?  Ive chosen to use the A314E with a 2x6 Strongback

2) Would someone be able to check over my drawings if they dont mind?  or at least post a dwg example file if they dont mind.  I know asking if a dwg would be too personal, just looking for some help to boost my confidence in myself.

**Note:  I did not draw the dwg file I am working on, it was given to me by the prof, and the wall thicknesses are pretty thich not your usual thickness**

SuperCAD · 发表于 2022-7-7 19:10:29

I have no idea what an "aplha" joist is, but the closest I could find is Alpa joists. If that's what it is, it's really just an I-joist with a mechanical chase down the center. Very similar to the Open Joist system which are trusses with ends that you can trim to fit. The size of the required joists depends on factors such as span, O.C. spacing, code required load capacity, bearing walls or loads from the roof or floors above, etc. For a layout, you typically start at one side and lay them out according the O.C. spacing until you reach the other end. You have to take into account the location of any toilets, plumbing stacks and mechanical chases unless you can get them to fall between the joists or shift the joists in a way that would allow for them to fit between the floor system.

I would be willing to take a look at what you have so far.

EDIT: I just looked up the A314E joist. This is a 2-1/2" wide by 14" tall solid lumber flange I-Joist with a 3/8" OSB web. That's a pretty big joist. What factors did you use to pick that size, or were you just taking a stab in the dark?

Tankman · 发表于 2022-7-7 19:24:27

Aren't joists selected depending on the weight they're required to support?

If this is residential, roof joists five [5] lbs per sq ft?

Look around here for sample *.dwg files: http://www.cadforum.cz/catalog_en/?cat=66&page=1

SuperCAD · 发表于 2022-7-7 19:34:33

Yes, but the local codes dictate how much weight they need to take. For instance, in my corner of Wisconsin, we need to support a load of 30 PSF of live load (live loads are like snow and furniture, in that they are not permanent loads and can be moved or adjusted at any time) and between 5 to 20 PSF of dead load depending on if you have storage space in the attic or not (dead loads would be for the building materials or, as the name suggests, items that are being stored in an attic that you may not move for a really long time).

Roof trusses here are typically designed to take a 30-7-10 loading. That means that the top chord can hold up to 30 PSF live and 7 PSF dead, and the bottom chord can support up to 10 PSF of dead load (pretty much just drywall and insulation). If there is a storage space in the attic, the bottom chord load will either be increased to 20 PSF or the truss will be designed as a "room in attic" truss and then it is increased to 30-40 PSF live and 10 PSF dead load to be more like a floor load.

Tankman · 发表于 2022-7-7 19:47:43

Don't know much 'bout joists, can build 'em, but know local codes vary from location to location.

A table is attached, I might have found it on this website, forget.

A nice table for your library. Jenny'O for lunch today?
Floor_Joists_Limiting_Spans.pdf

SLW210 · 发表于 2022-7-7 19:58:01

What design class are you taking? Post some of the info you were given to complete the assignment.

[综合讨论] Floor/Roof Framing Plan...help

发表回复

精选推荐