Opening up walls, widening doors, and freeing up the flow within the house is the dream of many homeowners, especially those who own older, pre-midcentury homes that have lots of walls and narrow doors.
Sectioning the house into separate rooms does have its advantages. It allows you to heat and cool rooms individually, plus it cuts down on the transmission of sound throughout the house. But removing walls and significantly widening doorways makes the house feel more open and airy and updates it. Plus, it's usually good for resale.
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 consider first.
Can You Remove a Wall by Yourself?
Most homeowners choose to hire a contractor for this heavy project. But homeowners can legally do the work in most communities.
Do-it-yourself homeowners must adhere to the local building code requirements and pass inspections, just like a commercial builder. Most municipalities limit this type of work to property owners doing their own work on property that they own and occupy.
Since all municipalities are different, check with your local permitting authority or building department for guidance.
Multiple Permits May be 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.
Your permit agency will want 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.
The National Electrical Code requires outlets every 12 feet along a wall in general areas. So, it's likely that the wall you intend to remove contains outlets that need to be terminated or re-routed, actions that may require permitting.
Removed Walls Must be Structurally Replaced
With building, if something is removed, it must be replaced with something that does the same thing but in a different form.
As a microcosm of wall removal, consider the construction of windows. Walls are the best way to hold up a house. Cutting a hole in the wall can only weaken the wall. The solution is a beam-like building element: a header.
Window headers replace the removed portion of the wall framing. The window header replaces parts of the wall but in a different form.
The same principle works for load-bearing walls on a larger scale. When you or a contractor remove a load-bearing wall, it must be replaced with either a structural beam or a structural beam and post or posts.
Structural Beam Only
A horizontal structural beam of sufficient structural quality must replace the wall. Other than the two ends, the beam with this arrangement has no vertical bearing points.
Structural Beam and Post
A horizontal beam with one or more intermediate posts between the two end bearing points is usually a better replacement than having a structural beam alone.
From a structural standpoint, the more vertical supports, the better. From an aesthetic standpoint, this limits flow and runs counter to the open floorplan concept—the reason for spanning long distances with a structural beam only.
Engineered Beams Provide Best Support
Four-by-fours and four-by-sixes at the local home center may look sturdy enough to replace a wall, but they aren't. Some type of laminated lumber will be needed, whether you laminate the beam yourself or purchase laminated veneer lumber.
Build Own Beam
A classic way to build structural beams is by nailing two or more two-by-tens or two-by-twelves together. Separating the boards is a layer of 1/2-inch plywood to create a built-up beam.
For do-it-yourselfers, a better option is to order laminated veneer lumber (LVL). 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.
Engineered beams are usually competitively priced. On the other hand, architectural LVL beams are expensive because the wood is meant to be viewed, not covered up with drywall. Non-architectural LVLs are far 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.
To make the beam flush with the ceiling, an alternative is 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 second option 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 Make the Project Cleaner
Intervening vertical posts (or columns) under a carrying beam 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.
How to Size Engineered Beams
Span tables are readily available but can be difficult for the layperson to understand.
Not just that but 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 do-it-yourselfer.
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. It's a cost that is worth it in terms of passing the building inspection.
Temporary Supports Are Required
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. 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.