Removing a load-bearing wall and replacing it with a beam is significantly different from removing interior non-load bearing walls. Load-bearing walls are structural elements that help support the weight of the house. Non-load bearing walls, also called partition walls, do not support loads from above and are simply there to divide spaces. If you're considering removing a load-bearing wall—whether you plan to do the work yourself or hire a contractor—there are some core issues you must address first.
You Can Do It Yourself
While a majority of homeowners choose to hire a contractor for this heavy project, in most communities, permitting authorities will allow homeowners to do the work. Do-it-yourself homeowners must adhere to the local building code requirements and pass inspections, just like any other builder would. Since all municipalities are different, check with your local permitting authority or building department for guidance.
Permits Are Required
Local permitting authorities regulate many aspects of home remodeling―fences, walkways, decks, ponds, wiring and plumbing upgrades, and structural changes, such as load-bearing wall removal. Most of these projects require a permit and inspections.
It should come as no surprise that your permit agency wants to know if you are taking down a wall that affects the structural integrity of your home. You may even need to submit a detailed plan regarding an alternative support system. Large walls may require an architect's drawing and/or an engineer's stamp of approval.
Removed Walls Must be Structurally Replaced
If you take something out, it must be replaced. To see how this works on a small scale, consider your home's windows. Walls are the best way to hold up a house; cutting a hole in the wall can only compromise this. But window headers―basically small beams―serve to replace the removed portion of the wall framing.
The same principle works for load-bearing walls but on a larger scale. When you or a contractor remove a load-bearing wall, it must be replaced with either:
- Beam: A horizontal structural beam of sufficient structural quality must replace the wall. Other than the two ends, the beam has no vertical bearing points.
- Beam and post: A horizontal beam that has one or more intermediate posts between the two end bearing points is also an acceptable replacement.
LVL Beam Provide Better Support
While it may be tempting, you cannot just grab a four-by-four off the shelf at the local home center and use it as your sole carrying beam. Depending on your situation, you may be able to use solid lumber or you can sandwich two or more two-by-tens or two-by-twelves together, sometimes with a layer of 1/2-inch plywood in the middle, to create a built-up beam.
An improvement is to order a laminated veneer lumber (LVL) beam. LVLs pack greater strength into a smaller space than similarly sized dimensional lumber. Thus, a 4-inch by 6-inch LVL will be stronger than a single piece of four-by-six dimensional lumber.
That said, you may be surprised that LVLs are not very expensive. Architectural LVLs are expensive because the wood is meant to be viewed, not covered up with drywall. Non-architectural LVLs are dramatically cheaper than architectural versions.
Replacement Beam Will be Below the Ceiling
In most cases, the replacement beam will be lower than the height of the ceiling. This is because the floor structure above rests on top of the beam. Alternatively, to make the beam flush with the ceiling, you have to cut back the floor joists above and set the beam into the plane of the floor, then hang the ends of the joists from the sides of the beam using metal joist hangers. This requires considerably more work than simply replacing the load-bearing wall with a beam below the joists, and may not always be an option in some situations.
Intermediate Posts Might Make the Project Cleaner
Intervening vertical posts (or columns) under a carrying beam admittedly do take away from that flawless open floor plan look. However, any kind of vertical support you can add under a horizontal beam will give your beam assembly far greater strength.
Additionally, if you are having issues with the beam protruding too far below ceiling level, posts can allow you to get by with a smaller, and thus less protruding, beam.
Seek Help With Beam Sizing
Span tables are readily available but are hard for the layperson to read. In addition, there are several factors to take into account when sizing beams, such as deflection, shear, deadweight vs. live weight, and roof loads. This makes beam sizing difficult for the amateur.
A structural engineer or contractor can consult with you on the proper size of the beam. Some structural engineers may agree to work on a per-hour basis.
Use Temporary Supports
Before removing any part of a load-bearing wall's framing, you must build a temporary support wall on both sides of the load-bearing wall. This is because the floor joists above may have their ends resting on the load-bearing wall. If you add temporary support on only one side of the wall, the joists on the other side may not be supported.
Structural Beams Are Critical
Well-built structures are constructed with redundancy in mind. Even when a major structural element such as an internal load-bearing wall is removed, the rest of the house may stay more or less intact. You see this often after a tornado or earthquake, where two-story houses have entire exterior walls ripped off yet the building remains standing.
The reason for this is redundancy. Even with the wall removed, a host of other interwoven elements, both structural and non-structural, pull together to keep the overall structure intact. When the wall comes out, flooring, subflooring, underlayment, neighboring walls, joists, rafters, and many other elements, come into play to hold the structure intact.
However, gravity will slowly take over and the house will begin to sag and slump. This should not be construed as an encouragement to remove load-bearing walls without a beam replacement; quite the opposite. It is a reminder that you should not be lulled by the power of structural redundancy. Gravity will win. It is just a matter of how fast this happens.