Guide · Structure · 13 min read
Load-Bearing Walls Explained: How Houses Carry Weight
A load-bearing wall carries weight from the roof, ceiling or floors above it down to the foundation. Some walls also brace the house against wind and earthquakes. Whether a wall bears load depends on how the framing above it spans, not on how thick it is. Removing one means building a new path for that load to reach the ground.
Reviewed by Daniel R. Whitcomb, PE · WA PE 48217
What loads does a house carry?
Engineers sort the forces on a house into two groups. Vertical loads push down: the weight of the structure itself (dead load), people and furniture (live load) and snow on the roof. Lateral loads push sideways: wind against the walls and roof, and the inertia of the house when the ground shakes in an earthquake.
Every load has to follow a continuous path from where it starts to the soil. Snow on the roof goes into rafters or trusses, then into the walls or beams that support them, down through studs or posts, into the floor framing and foundation, and finally into the ground. Lateral loads follow a different path: through the roof and floor surfaces, which act as horizontal diaphragms, into specific walls that are braced to resist racking, and from there through anchor bolts and hold-downs into the foundation. A load-bearing wall is any wall that is a link in one of those chains.
What are the four kinds of walls in a house?
| Kind | What it carries | Where you find it |
|---|---|---|
| Exterior bearing wall | Roof, ceiling and floor edges, plus lateral bracing | The perimeter of nearly every house |
| Interior bearing wall | Joists or rafters that span to it from both sides | Often near the middle of the house, under the ridge or a girder line |
| Shear wall | Lateral forces from wind and earthquakes | Exterior walls and selected interior walls with structural sheathing |
| Partition wall | Only its own weight | Interior walls running parallel to joists, closets, many truss-roof houses |
A single wall can be more than one of these. An exterior wall is usually both bearing and shear. An interior wall can carry a point load from a post above without carrying joists along its length. That overlap is why removing any interior wall deserves a look at the framing above it first.
How does the framing above a wall decide whether it bears load?
Stick-framed roofs
Many houses built before the 1970s have roofs framed with individual rafters and ceiling joists cut and assembled on site. Ceiling joists rarely span the full width of the house in one piece; they run from each exterior wall to an interior wall near the middle and overlap or splice there. That middle wall carries the ceiling and often supports struts or braces that hold up the rafters at midspan. In these houses, the central wall is almost always bearing.
Roof trusses
Trusses are triangulated frames built in a factory, joined with metal plates, that typically span from one exterior wall to the other without interior support. In a one-story house with a truss roof, interior walls often carry no roof load at all. Trusses became common in many Eastside subdivisions from the late 1960s onward. Some trusses are designed to bear on an interior wall, so the truss layout still has to be checked.
Floors over a lower level
On the lower floor of a two-story house, the floor joists of the upper level need intermediate support when the house is wider than a joist can span. That support is a bearing wall, a beam or a girder on posts. Upper-floor walls that sit directly on top of lower walls usually mean the load travels straight down through both.
Basements and crawlspaces as evidence
The foundation below tells you where the house expects loads. A girder on posts running down the middle of a crawlspace, or a thickened footing under a basement wall, marks a bearing line above it. Where nothing supports the floor under a wall, that wall is less likely to carry significant load.
Which common beliefs about bearing walls are wrong?
| Belief | Reality |
|---|---|
| A wall with a doubled top plate is bearing | Nearly every framed wall has a doubled top plate; it says nothing about load |
| A thick wall is bearing | Thick walls often just hold plumbing or ducts |
| A wall with a header over its door is bearing | Builders often frame headers in partition walls by habit |
| Interior walls in newer houses are never bearing | Two-story houses of any age have bearing walls under the upper floor |
| If the ceiling does not sag when you push it, the wall is not bearing | Bearing walls can be removed briefly without visible sag, then fail slowly over weeks |
What replaces a bearing wall?
A wall carries load continuously along its length. A beam collects the same load and delivers it to two or more points. The choice of beam depends on the span, the load, the depth available and the budget.
| Beam type | Character | Typical use |
|---|---|---|
| Built-up dimensional lumber | Inexpensive, limited span, can shrink | Short openings with light loads |
| LVL (laminated veneer lumber) | Engineered, stable, stronger than sawn lumber | The most common remodel beam |
| PSL (parallel strand lumber) | Engineered, very strong, comes in wide sections | Heavy loads, long spans |
| Glulam | Laminated timber, attractive when exposed | Exposed beams, long spans |
| Steel wide-flange | Shallowest for a given load, heavy to install | Long spans with limited depth, heavy upper loads |
| Flitch beam | Steel plate bolted between wood members | Where depth is tight and steel alone is impractical |
The beam can hang below the ceiling or be recessed into it so the ceiling stays flat. The trade-offs between those two options are covered on our wall removal service page.
How does the load get from the beam to the ground?
This is the part of a wall removal that homeowners rarely think about and engineers worry about most. A wall spreads its load along a long footing. A beam concentrates the same load at its ends, sometimes several thousand pounds on each post. The post must be strong enough not to buckle, it must sit on something that can carry it, and that something must sit on soil that can carry it.
In many houses, the post lands on a floor between joists, where nothing below is designed for a concentrated load. The fix is solid blocking or a new post directly below in the crawlspace or basement, on a new concrete footing sized for the load and soil. On two-story houses, the load path may run through two floors before it reaches the foundation, and every level needs a continuous support.
Why does lateral bracing matter when a wall comes out?
Some interior walls, and most exterior walls, are part of the system that keeps a house from racking sideways in wind or an earthquake. Their sheathing and nailing, along with hold-downs at their ends, transfer lateral forces to the foundation. Removing a long section of such a wall, or replacing an exterior wall with glass, reduces that resistance.
The engineer checks whether the remaining walls can carry the lateral load. If not, other walls get added sheathing and hold-downs, or a moment frame or engineered shear panel is installed at the opening. This is a common reason why two wall removals that look identical can have very different costs. In older houses, it is also a good moment to consider seismic upgrades at the foundation.
Next steps before you open a bearing wall
If you are planning to remove or open a wall, start with the checker for a quick read, then have the framing confirmed on site before demolition.
Related questions
More about walls and loads
Can I remove part of a bearing wall instead of all of it?
Yes. Shortening a bearing wall or cutting a wide opening in it is common, and works the same way as full removal: a beam spans the opening and delivers the load to posts at each side. The remaining wall sections often serve as the post locations, which can make a partial opening simpler than full removal.
Why did my ceiling crack after a wall was removed years ago?
Cracking along a former wall line often means the replacement beam is undersized, deflecting more than the finishes tolerate, or that the posts or footings are settling under concentrated load. It can also be ordinary drywall movement. An engineer can check the beam size, its supports and whether the work was permitted.
Are walls around a staircase load-bearing?
Often. A stair opening interrupts floor joists, and the cut joists hang from headers that carry their load to the sides of the opening. Walls beneath those headers frequently carry concentrated loads, even if they run parallel to the joists. Treat stair walls as bearing until the framing is checked.
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