Sistering Floor Joists

[hong0019]

I am remodeling my basement and I would like to remove a load bearing wall and reinforce the existing joists with sister joists. I would like to know if my method of sistering joists would be adequate to be able to remove the load bearing wall. My joists are 2x10, spacing of 16". There are 8 joists in the area of question and the area is 12'x18'. The current span of the joist with the load bearing wall is 18'. The load bearing wall is located 14' from the center beam.

[Doug Aleshire]

hong0019,

I doubt you can sister any additional 2x10 members to this to accomodate what you need. 18 feet is quite a distance so removal of the load bearing wall is going to increase the load on any "sistering". It may be possible to use LVL's but I would suggest a structural engineer to confirm such an application.

Is it possible, that a beam could be installed to replace the bearing wall? 12' span right?

Do you have the room to install posts or is there walls to left and right of this area to do this?

Hope this helps

[hong0019]

What are LVL's?

A beam spanning the 12' was my alternative. I didn't like this idea because it lowered the ceiling height. My current ceiling height is 93". How big of a beam would I need? How do I support the beam? Do I need to drill a hole into the concrete wall for the beam to fit into or can I install posts at the ends of the 12' beam?

The 12'x18' area is actually part of a 25'x14' area with the extra 4'x12' area jutting out of the 25'x14' area. The 18' and 14' are the joist span. Hopefully you can picture this. What was your idea around "install post"?

[Doug Aleshire]

hong0019,

LVL' are these,

http://www.apawood.org/level_b.cfm?content=prd_lvl_main

I would need more information to tell you want you need as well as a better idea of current layout.

The post idea was if the wall is being removed and if your planning concepts would allow it, the posts would support the ends of the beam. As you mentioned you now have a concrete wall on one side so I don't know what is planned for this room and if you would be OK with a post location (this means a pad of approx. 30x30x10 (as an example) depending on the load it must carry.

Unsure if the load bearing wall you mentioned has a "thickened slab" under it and this also makes a difference in what would need to be done.

[Doug Aleshire]

hong0019,

Thanks for sending that sketch.

You didn't say what the reason is to remove this wall but a beam for this short of a span could be made from an LVL. Option is a flush beam but to make things easier, I have come up with this.

Use either a 3 1/2 x 11 1/4" LVL (basically 2 - 1 3/4") or a 5 1/4" x 9 1/4" LVL. These could be placed underneath your floor joists. Since this is between 2 bearing walls that have footings - you only need to frame a support wall approximately 6" long. The footings are wide enough to avoid pad and post install.

Hope this helps!

[hong0019]

Thanks for all your help. We are planning on using that space to put a tv, home theater system and shelving units in the corner. It is hard to leave up that bearing wall and lose all that space.

For your comment about framing 6" long, I was planning on framing all the outerwalls with 2x4's. Is that good enough to support that beam? Also, how do I go about framing the wall to incorporate the beam? Do I need to sandwich the beam between two 2x4 and put 2x4's underneath the beam with a top plate to cover the width of the beam?

[Doug Aleshire]

hong0019,

You're very welcome!

I would recommend at least a 2x6 wall - It is best to have 6" of support for this beam. If you review the previous link of the manufacturer it will describe that in detail. You can make a pocket within this wall for the beam. Place 2x6 directly under this to ensure that the beam is fully supported.

You explained it well and already know what to do.

Good Luck!