What are load-bearing walls and how do you know if a wall is one?

Load-bearing walls can be difficult to open up adjacent rooms or enjoy open-plan living, but how can you tell if a wall is load bearing? Understanding that any wall can be load bearing is a good starting point, even if it is made of studwork and appears flimsy.

When I first started renovating a house, the previous owners assured me that a dividing wall in the sitting room was "definitely not load bearing," because they'd installed it themselves beneath one of the house's historic timber beams, which appeared to be holding the load instead.

It was supposed to be a simple job to dismantle it to open up the room, but as I pulled off the gypsum plasterboard and removed the insulation, it appeared that the studwork was doing more work than expected.  

The old timber beam above appeared to be well supported by timber uprights on one side of the wall, but closer examination from the other revealed hidden gaps between the uprights and the beam. Historic woodworm had also disintegrated parts of the beam, and previous careless power tool use had left deep cut marks in it.  

It teaches an important lesson: always remove all plasterboard and insulation before starting work on removing a wall so you can see what's going on underneath. And, if in doubt, always consult a structural engineer. That's exactly what I did, and I'm glad I did.  

If a wall turns out to be load bearing, you'll need a structural engineer to calculate an alternative support and get building control approval. Here's our expert guide to determining whether a wall is load bearing.

What exactly is a load-bearing wall?

"Internal walls, as opposed to the insides of external walls, come in two distinct flavors: load-bearing and non-load-bearing," says Mark Brinkley, author of the popular Housebuilder's Bible and an experienced self-builder.  

"A load-bearing wall supports a roof, floor, beam, or another wall above it." It must be slightly stronger than a non-load-bearing wall, and it must have additional support beneath it, usually in the form of an additional foundation trench.  

"Load-bearing walls can have a significant impact on renovations, particularly when an existing wall is to be demolished." In these cases, it is critical to know whether or not the internal wall is load bearing, because if it is, an alternative means of support must be provided.

"If you have any doubts, have the building professionally surveyed so you know what you're dealing with." The building inspector will almost certainly require you to hire a structural engineer to design and approve the plan if you are rearranging loads.  

"The consequences of demolishing a load-bearing wall without knowing what you're doing are unthinkable." Non-load-bearing walls, on the other hand, serve as little more than room dividers and can be easily altered or even removed. "

How to Determine Whether a Wall Is Load Bearing

The first point to emphasize is that load-bearing walls can be made of blockwork or studs. Similarly, non-load-bearing walls can be both.

According to chartered structural engineer David Gallagher of Allan Corfield Structures, there are some good indicators that a wall is probably load bearing and should not be touched without professional input. (Opens in a new window) These are some examples:

• Exterior walls Any exterior walls to your building are likely to form the structure of your property and thus are highly likely to be load bearing.
• Central walls are typically load bearing walls that run from front to back or side to side. This can be indicated by a consistent wall line between floors.
• Wall with a wall immediately above it Generally, load-bearing walls are stacked, so anything on a first floor that goes all the way down to the ground floor is likely to be load bearing. It could also be supporting the roof, so you should be cautious.  
• Wall with perpendicular floor joists on top The best way to tell is to open up the ceiling and look. Where this isn't possible, according to David Gallagher, there are other clues. "The detail at the top of the wall differs between load-bearing and non-load-bearing walls," he says, adding that your engineer or contractor should be able to spot these indicators. Even so, you should always confirm this by opening it before removing it.
• If there are any intermediate beams nearby, "we would often make the assumption that the joists are spanning in the shorter direction, which would be typical," David Gallagher says. "However, that is not always the case; occasionally, you will have an intermediate beam." Some older homes will have a beam in the center of the living room, to which the joists may span, and your wall may be supporting the beams. As a result, you must exercise caution. "
• Racking panels on stud work If a studwork wall is lined with OSB, the likelihood that it is structurally significant increases because OSB is frequently used to strengthen a structure.
• Tenement homes should be treated with caution because they were not built to modern standards, and their load-bearing walls are not always tied to other walls. "Once you start changing them, they can be quite sensitive," says David Gallagher.

"As engineers, we have access to historic, typical house arrangements as well as any archive drawings that are available," David Gallagher adds. "The archive drawings are the best way to determine whether or not a wall is load bearing." If you are looking at tenements or relatively new houses with replicated layouts, there are typical house layouts. Most people adhere to a general rule. "

According to Paul Hymers, a building control officer in Kent, a common mistake is assuming a wall is only load bearing if it supports a floor. Roof loads, as well as the loads of other internal walls, beams, and joists, can transfer down.

"In traditional roofs, the ceiling joists are commonly supported on a central spinal wall, with the rafters propped up from it by diagonal struts pinning the purlins that carry them." Of course, the use of trussed rafter roofs has eliminated the need for spine walls to support the roof, but floor structures have not changed," he explains.

"Inner walls may also serve as load-bearing elements by simply buttressing the external walls, providing support against wind-loading." Because all external walls, like beams, have a maximum span, they are subject to both horizontal and vertical wind loads.  

"The length an external wall can run unsupported depends on its thickness and exposure to the elements, but think of the wall panel as a wind break that needs to be supported, with buttressing support, at the returning ends and possibly along the way."  

"A properly sized masonry chimney or pier can provide this additional support, but more often than not, internal walls perpendicular to it are used in this capacity." "

Yes, load-bearing walls can still be removed; however, you will need to pay a structural engineer to create calculations for a suitable beam that will need to be installed to support the load once the wall has been removed. The structural engineer will almost certainly include a thorough risk assessment of the work as well.

"Your structural engineer will calculate the weight imposed by each construction element, total it, factor it, and determine the ultimate design load on the beam." The beam itself can be specified using this figure and the maximum bending moment," says building control officer Paul Hymers.

Building Regulations must be obtained before removing load-bearing walls. To obtain this, contact your local building control officer at your local council (who are usually surprisingly easy to contact) or a private approved inspector, who will provide you with a quote for the visit to sign it off. Alternatively, your builder may be able to arrange this for you.  

Do all of this before beginning the work, as they may have additional requirements. Your structural engineer's drawings must also be submitted to your building control officer. When the work is finished, they will double-check that the beam installed is the correct one according to the drawings.  

Obviously, you'll want to make sure your building inspector comes out before you plasterboard over or cover the beam so they can inspect what you've done.

If you are still unsure whether you should remove a load-bearing wall, read our guide on how to assess your home for renovation.

What kind of beam do I require?

The type of beam recommended by your structural engineer is highly dependent on your home, the span of the new opening, and the amount of load it must support. Typically, beams are made of steel or concrete, but this is not always the case.

For example, for my load bearing wall, a flitch beam was recommended. This is made up of bolted together structural-grade timber joists and steel plates. This is an unusual choice, but I believe it is because it will support another beam.

My first choice was an oak beam, but the new oak would not have matched the historic oak in the room and might have looked out of place.

Steel beams will require fire protection if they support floors or walls above, and a cradle is usually formed around them and covered with 12 gauge steel. 5mm thick fire-rated plasterboard (or two 9mm thick sheets) 5mm layers) and a plaster skim finish that provides at least 30 minutes of protection

Meanwhile, a simple steel was not recommended because Building Regulations consider steel to be unsuitable in a fire, necessitating a fairly thick layer of fire-proofing. This would have had a significant impact on head height in my build.

Concrete beams are frequently preferred for smaller openings. In fact, concrete is the only acceptable material in a chimney or above a log burner or open fire. Steel or wood are no longer acceptable materials.

If you're wondering why steel needs more fireproofing than wood, my understanding is that when steel melts, it loses structural integrity fairly quickly. A timber, on the other hand, will retain its structural integrity for a longer period of time because it must burn all the way through before collapsing.

Signs that a wall is not load bearing

If the top timber of the studwork does not touch the timber joist of the floor above or any beam, the wall is not load bearing. In general, if the wall is not in contact with anything structural,

For example, if the studwork butts up against a plasterboard ceiling rather than the joists. This is most likely a room divider that was added later rather than a load bearing structure.  

To ensure that this is the case and that there are no hidden load-bearing structures inside the wall, remove all plasterboard from the studwork. If you have any doubts, it's always best to consult a structural engineer because getting it wrong can damage the structural integrity of your home, making it unsafe.

According to Chartered structural engineer David Gallagher, the type of studwork used is not a reliable indicator of whether the wall is load bearing or not. This is due to the fact that most walls use C16 and C24, both of which can be used for load-bearing walls.

As previously stated, a stud wall can easily be installed without the intention of being load bearing, but end up holding a load. As a result, it is always necessary to evaluate each wall individually.

This will vary depending on your project, but it is likely that this type of project will cost at least £2,000 To give you an example, consider my three A 2 metre-long load-bearing wall removal will cost me £2,262, but if I hire a separate plasterer and decorator, it will cost me an additional £300-£400.

To break that down for budgeting your house renovation costs, building control would have cost £220 VAT (£264). I was able to negotiate it down to £110 VAT (£132) because I added the works to an existing building control application (as I previously stated, building control can be extremely beneficial).  

My structural engineer visit and drawings cost £525 VAT (£630), and I have a quote for two experienced builders to remove the wall (which I didn't want to do myself) for £1,250 VAT (£1,500), which includes materials and all the necessary equipment. I was renovating on a budget, so I had already removed all of the plasterwork myself, saving money there as well.

To recoup some of the unexpected costs, I intend to plasterboard, plaster, and paint it myself. However, a plasterer can charge anywhere from £150 to £250 per day, and a decorator can charge even more if either brings an apprentice with them.

"Costs may be higher if you intend to open up an internal masonry wall - for example, a brick wall in a period home - which is likely to be a labor-intensive task." Consider the cost of repairing the flooring between the two spaces after the wall is removed," says Claire Lloyd, editor of Homebuilding & Renovating.