Beam structure to support two joists

13 years ago

Hello, this is my first time posting. I have a load bearing wall that I want to remove. The critical load it is carring is two sets of neighboring joists, a span of 32". Having concluding that I can't successfully replace or reinforce/splice these joists so their load can be carried by other walls, what I would like to do is replace this wall with a beam below the joists, about 4' long. The ends of that beam would be attached with hangers to 8' long members, running perpendicular to the beam. These 8' members are supported by posts/studs at each end (a total of four posts). Where the posts are located can easily be integrated into existing walls, so that I have a clear area where the bearing wall used to be.

Here's a sketch of the current situation, showing the framing: joists, brick wall and the supporting wall. The far ends of the joists are properly supported (not shown). All joists are full 2" thick by 7-1/2" tall. The light wood colored joists are the ones the need support. The black cylinder represents a toilet drain above -- presumably one of these joists was cut to allow for this drain, way back when.

And here's a sketch of what I'm proposing to do:

Questions that I have are:

1. what should be the dimension of the 4' long beam

2. what should be the dimension of the two 8' long carrying beams?

3. is there a better way to do this?

- John

Sort by:Oldest

Comments (4)

austinspace
Original Author
13 years ago
... my thought was to use double 2x6's as the beam, attached by beam hangers to double 2x8's at each end. Looking for validation on size of lumber here, and the design overall. Thank you.
macv
13 years ago
Without a floor plan it's impossible to say if the post placement makes sense but the loads from the posts should be carried to the foundation through appropriate structural elements (beams, joists, etc.).

The beam connections to the free standing posts are unstable; perhaps parts of the posts could go to the roof.

Without knowing the spans (unsupported lengths) of the cut roof rafters and the roof loading it is not possible to size the beams other than by guessing.
Related Discussions
Beams and joists
Q
Comments (4)
Jacqmar, did you get a full set of blueprints with the house? You should have blueprints for the plumbing, electrical, structural, and yes, the support. I believe that your home is built with specific locations for the support beams. I did not put my home on a basement, but I got the blueprints needed to do so. The posts are not all equidistant on the plans for my home, but vary from 8 to 16 feet. I know nothing whatsoever about the beams.
...See More
Need help with beam support- what company/speciality can add beam
Q
Comments (2)
How big is the addition? If the area is sinking it sounds more like a foundation issue. You dig too deep. Back fill and don't compact. Set the footing forms and pour. After the weight of the whole building is assembled, the soil settles. Along with it, you're addition. A competant contractor should be able to direct you. I have a daughter in Charlottesville. Great little city. Ron
...See More
Removing load-bearing walls - cost for recessed beam vs. under joists?
Q
Comments (34)
Live_wire_oak, I certainly wouldn’t dispute that most contractors would not use double 2x4’s for a header despite what the code allows (and therefore what is safe). I suspect that you and I know there are many things a contractor does when framing a house that has more to do with just meeting code. It’s much easier to tell your employees to frame every door and window with 2x12s to be safe and not have to do code checks for every opening. I will say though, the better framers in the small minority will take the time to understand what the actual header requirement is so as not to overbuild and create unnecessary thermal bridging.
...See More
Shed roof extension/support beams/old wall, when is it safe to remove?
Q
Comments (3)
Thank You for the comment it does look like a hack job ..ametuer hour at its finest. Dimesnions are 8ft Height , high side against house. slopes to 7 ft on low side, outside wall. Outside wall spans 8ft in L, width if u may. its a 3/12 pitch roof so its not an issue. Listen im new at this stuff i really like it , i get how things go but sometimes i run into a quandry here and there. This was one of em. The beam size's on the outside wall joist are actually 4x4 posts in concrete. so and also 2x6 as the ledgers, i installed 1. along house 2. middle where new roof meets old. and on the outside wall the 3 4x4 post into cement as outside support so i kinda get the whole support structural idea. Its solid 0 give anywhere. flush, level, squared, its just was rebuilt w used wood not new lumber . so i just wasnt sure if removing those older wall joists is ok. and the window isnt going where ur thinking its going next to door where there isnt a roof butt so. yeah looks like a double a..s..s i understand but im just not as sseasoned on some structural techniques and what bears what load etc sorry but thanks so much for at least responding i really do appreciate it. Heres some pics of a bit better build i just did on a 8x8 shed. thats gotta be better i hope lol. let me know what u think it was my first real build of a substance structure. lol this what i just asked u about and what it was previously as u see lean to attached was just too low and so i thought it be easy to just pop the roof up and on it and extend the roof for head space but just got a little unsure structurly on how far out is ok for this low slope roof.
...See More
execon
13 years ago
John,

In the first picture you have the right idea of a temporary supporting structure while you do the work. If the existing joists are 2x8's then you should double or even triple the ones that will stay on either side of the proposed opening (known as "trimmer joists"). Of course the span of the existing joists will dictate whether you need to double or triple the trimmer joists. The trimmer joists will have to be supported on both ends to carry the weight of the load. The ends of the trimmer joists nearest the brick wall can have a 2x ledger board attached to the brick to provide support but should also have a number of 2x's layed flat against the brick under the ledger from floor to ledger to give additional proper support to the ledger.

The "cross beam" also known as a "header" or "girder" should be a double 2x8 header supported by joist hangers. This should eliminate the need for any supporting posts underneath giving you a true clear area.

Hopefully this helps.....
sombreuil_mongrel
13 years ago
You could save a lot of effort by installing a flush header between the two solid joists, and then notching 2 posts to the joists as near as possible to the header. As has been said "something" needs to carry the load to a suitable girder and ultimately the ground. IOW it won't do to support this on just flooring or just another joist beneath the flooring. I would investigate a second header at the brick wall, and removal of the old inadequate (cut) joists, and installing new short joists placed to miss the plumbing.
If you are resigned to having posts, there is no real need IMO for four of them, two would suffice if they have bearing on structure.
Casey

Beam structure to support two joists

Comments (4)

austinspace
Original Author

macv

Related Discussions

execon

sombreuil_mongrel

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Beam structure to support two joists

Comments (4)

austinspaceOriginal Author

macv

Related Discussions

execon

sombreuil_mongrel

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

austinspace
Original Author