Modifying a Load Bearing Wall
Summary: Modifying a load bearing wall with the addition of archways or openings is usually possible. Creating the proper support in the weight bearing wall for the shifted load is a task best left to the professional structural engineer. Follow these tips and tricks to craft your desired opening with the proper supports and beams.
I remember the first load bearing wall I modified. I was in my early twenties and had never done it before. It was in a massive old home in Clifton, an inner city suburb in Cincinnati, Ohio. I was working as a sub-contractor for a remodeling company and knew just enough to be extremely dangerous. Fast forward . . . The house didn't collapse and in fact the enlarged opening I created has not sagged to this day. But I must tell you I had lots of luck that day. All sorts of things could have gone wrong.
Knowing the Loads
Creating archways or openings in bearing walls can almost always be accomplished. It simply becomes a matter of where the loads are going to be concentrated. A typical bearing wall tends to transmit a fairly equal amount of load down to the floor below via the wall studs. If you decide to create a large opening in the wall, then the loads above the opening must be shifted to the sides of the opening using a properly sized beam. Will a double 2 x 6 be enough? How about a single 2 x 12? The truth is, only experienced carpenters who have successfully installed beams, or structural engineers who are trained to size and specify beams, should make the call. Do not try to conjure up your mystic powers and guess.
Temporary Support
If you want to install a beam in an existing bearing wall, there are all sorts of tricks and methods. If it is an interior wall, there is a cool way to install a beam without building any temporary support walls. You need to have access to both sides of the wall into which the beam is going to be placed. All that you do is simply install half of the beam at a time. You make 1.5 inch deep notches at the top of one side of the wall and slide the beam into this recess. Add the king studs at each end of the beam that run from top plate to bottom plate. You then add the jack studs next to the king studs. These framing members actually support the load from the beam. If the rough opening of the new beam is 72 inches or less, you generally only need one jack stud at each end. Once all of this is in place and the jack studs are solidly supported from beneath, you can take out the remaining old notched wall studs as the weight of the wall will be carried by the one half of the beam that is secure and in place. Be sure to have the second half of the beam already cut and ready to slide in place!
When You Need One
Often you can't do the cool trick I described. Perhaps you are working on an outside wall and want to salvage the wall finish on the exterior side of the new beam. You need to build a temporary wall 3 feet back from the existing bearing wall.
But stop! Before you start to build the wall, you must build the beam and lay it on the floor next to the existing wall. Why? Many a rookie carpenter has built the temporary wall, created the hole in the existing wall only to find out they can't get the beam threaded into the narrow space between the old and temporary walls!
The temporary support wall needs to have a top and bottom plate, and the studs of this wall need to fall as closely as possible under and above the floor and ceiling joists. The studs are cut tight so they have to be tapped in place. I simply add a few toe nails that just penetrate partially into the top and bottom plates. Be careful about ruining finished floors and ceilings!
Masonry Walls
Don't even think about creating an opening in a masonry wall without help from a professional. Masonry walls are very heavy. The weight from steel roof members and floor loads can be enormous.
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Comments:
DIANE STRATTNER 01 Jan 2008, 15:32
I HAVE A LOAD BEARING WALL THAT WE WILL BE TAKING DOWN WHICH PUTTING IN A
NEW HEADER WILL WORK, BUT THERE IS A 12 ANGLE WALL WHICH IS LOAD BEARING
ALSO BUT I WANT TO REMOVE IT SO THE SPACE IS WIDE OPEN DO YOU HAVE ANY
IDEAS. ON HOW TO DO THIS>
AsktheBuilder 01 Jan 2008, 15:51
Diane,
There is no need to scream...... :-> You need to get some help from a structural engineer. You are in over your head if you have to ask a question like this.
Christopher Casillas 05 Jan 2008, 12:48
Quick question here,
I read your paragraph above about supports. Are wall jacks with a 2X6 or 2x10 beam okay, or is a proper wall 3ft inside of the main the only way to go? I have to rebuilt my basement exterior wall that was built incorrectly, and without being attached (ie top plate, bottom plate)and a mickey mouse cutout for an AC. Thanks for the support!
AsktheBuilder 05 Jan 2008, 14:10
Chris,
I would build a proper wall that is cross braced. Do NOT underestimate the loads you are dealing with. They are significant.
mechele 09 Jan 2008, 20:18
I have a new opening in my wall that is load bearing. I need to know if
there is a fomula for the distance of the opening. I need a 6 ft opening,
most have said 2,2x6 will be enough to support that span. What is your
opinion.
AsktheBuilder 10 Jan 2008, 07:42
Mechele,
There is indeed a formula once you know the loads on that portion of the wall. If you want peace of mind instead of the free unprofessional advice from the peanut gallery, then hire a structural engineer to do the calculation.
Dave 15 Jan 2008, 10:59
I would like to install a double pocket door to enlarge a dinnig area and
sitting area for a more open concept.
however my ceiling joice are running the oposite way of wich i would like to make my opening how do i install a header for support
AsktheBuilder 15 Jan 2008, 11:06
Dave,
Simple. Consider hiring a structural engineer to size the proper header AND give you a plan of how to install it. You could have MASSIVE concentrated loads at that location. Read all about that in my other Structural category columns.
Mike 21 Jan 2008, 11:05
Dave,
We're considering installing a 3-panel sliding glass door in the exterior wall of our home, overlooking our pool from our bedroom. The house is a typical slab-on-grade Florida tract house, with all exterior walls supporting the roof trusses, and wood framing behind a brick veneer. as well as a two-foot overhang with vinyl soffet. The builder used butted 2 x 12's across the top of all the existing wall openings (windows, doors). The widest existing opening is six feet (double-width windows). 1. Does one typically need a building permit for this type of modification? 2. Is this something a "weekend warrior" could eventually accomplish over the course of several weeks? 3. If not, could you throw a number at me as to what it might take to have it done professionally? Thanks.
Mike 21 Jan 2008, 11:27
I meant to address my post to Tim. Sorry about that.
mk View all comments |



