When you’re updating a home, it’s common to think about reconfiguring the interior walls. Perhaps you want to make the space more efficient or bring in more natural light. Or maybe you want to remodel a kitchen or bathroom.
When changes involve moving walls, the question often comes up: “Are these load-bearing or partition walls?” Instinctively, most people know it’s more complex to work with load-bearing walls than partition walls. But how can you tell if a wall is load-bearing when you can’t see the framing? There are quite a few signs to help you answer this question.
Before I share the signs for how to identify a load-bearing wall, it’s helpful to understand how a wood-framed home is built. This is the most common residential building method here in the Northwest. (The video shows what framing looks like and some of its features.) There are a variety of structural framing designs and methods, from traditional to modern, simple to complex. Knowing the structural framing design for your home will make it easier to determine which walls are each type.
Also, it’s important to remember your structure will need to be verified by an engineer and architect before remodeling. They will tell you if a certain method of structural remodeling is needed.
Below are suggestions for how to identify load-bearing walls in different areas of your home.
Identifying load-bearing walls in the basement
The basement is a good place to start, especially if it’s an open basement. Look for any posts supporting beams spanning the distance of your home down the middle. This combination often indicates the floor joists are supported by this beam. If the floor is open, you should see the floor joist's sitting on the foundation and sitting on that beam down the middle. That beam is load-bearing and the posts carry the load, called point loads, down to a concrete footing.
Identifying load-bearing walls on the main floor
Keeping in mind what you saw in the basement, go upstairs to the main floor and look around. Is there a center wall that’s stacked on top of the beam below in the basement? If so, it’s likely a load-bearing wall, especially if it’s supporting the floor joists from the second floor. Any door openings in that wall may have headers as a way of supporting the floor above, through the span of a doorway. There’s a stud on either side that brings the load to the wall plate, through the joists, into the beam in the basement, down the posts, and into footings.
Identifying load-bearing walls if you have hardwood floors
If you have hardwood floors, look at the direction of how the floorboards are laid in; they will be perpendicular to the floor joists below. If you’re looking at a floor and don’t know which direction the floor joists are going, looking at the direction of hardwood floors is a good indicator. Then, imagine where the floor joists are sitting on either end. They’re likely sitting on an outer wall, going through to a support wall or to a beam in the middle of the house. If your hardwood floors change direction somewhere, the floor joists also likely changed direction.
Identifying load-bearing walls using floor joist direction
Once you identify the floor joist direction, walls that are parallel to the floor joists can generally be considered non-load bearing. This is not always the case, but it often is.
Identifying load-bearing walls upstairs
In the upper floor, it’s not always easy to know which way the floor joists run because the ceiling in the main floor has plaster. If you have drywall, the ceiling may show the location of drywall nails or screws by consistent little divots, or pops, created over time that indicate the direction of the joists. Hardwood floors will indicate this as well. Heavy bathrooms (e.g., bathrooms with tile, heavy tubs, or marble showers) often have floor joists that are doubled up to handle the extra weight. In these cases, the load is transferred to the exterior wall and interior beams or walls.
Identifying load-bearing walls in the attic
Up in the attic there are also indicators of load-bearing walls. In modern homes, trusses generally bring the roof load to the exterior walls, making all interior walls partition walls (but not always). Older homes and some newer homes don’t have trusses; they have framed-in-place roof rafters. Usually the problem in these homes is the ceiling joist is a very long span carrying heavy plaster or drywall, and if a partition wall is removed, these joists sag under their own weight. Another thing to look for in an attic is the knee braces sometimes installed to keep the roof joists from sagging under the weight of the roofing. Often these braces are connected to the top plates of interior walls.
Helpful tips to keep in mind when moving walls
When moving or putting an opening in an existing wall, try to think about the changes as a series of deductions. (At first, these are educated guesses.) This is the dreaming stage—have fun with it! These deductions will give you different ideas for to proceed. When you’ve settled on your final plan for the space, the next step is to professionally verify the structure. It’s worthwhile to talk to an architect, designer, or contractor before and during the design stage of a renovation, so you know what to expect for cost and what will be required for construction.