New opening and beam design
Forming a new door, window or opening in a load-bearing wall means a beam or lintel to carry the wall above. We size it, design the bearings and prove it for Building Control, across the UK.
Do I need a beam for a new window or door?
If the wall is load-bearing, yes. Any new opening in a wall that carries load needs a lintel or beam to pick up the masonry and any floor or roof above. We size it and design the bearings so Building Control accepts it.
Carrying the wall over a new opening
Cutting a new opening into a load-bearing wall, a wider doorway, a new window, a set of bifold doors, a serving hatch made into an arch, removes a piece of wall that was carrying everything above it. That load, the masonry over the opening, the floor and roof bearing on the wall, has to be picked up by a beam or lintel spanning the gap. The member sizes to the load above and the span across, and the wider the opening the more it has to carry.
For modest openings in a cavity wall we design a proprietary steel or concrete lintel with a cavity tray over it, sized from the load and the span. For wider or more heavily loaded openings we size a rolled steel section, a universal beam or column, or a pair of them across a cavity, one for each leaf. We work out the triangle or full height of masonry acting on the beam depending on the wall above, so the section is neither underdesigned nor needlessly heavy.
Bearings, padstones and the load below
A beam is only as good as what it sits on. Each end bears onto a padstone that spreads the reaction into the masonry below without crushing it, and we check the bearing stress against the strength of the brick or block. For a heavy beam the padstone may be a cast concrete block or a spreader, and the masonry pier beneath has to be wide enough and sound enough to take the point load down to the foundation.
We follow the load from the beam ends down through the wall to make sure it has somewhere to go. On a new opening near the end of a wall, or above another opening, the load can concentrate on a short length of masonry, so we check the pier and, where needed, specify strengthening or a new footing. This is the check that stops a beam being installed over a pier that then cracks under the concentrated load.
A quick, well-detailed package
A single new opening is usually a compact job, so we keep the package focused, the beam or lintel schedule, the padstone and bearing detail, the load path check and a clear drawing your builder can work from. Even on a small job the temporary propping matters, so we set out how the wall above is supported while the opening is cut and the beam goes in, and the order of work to strike the props safely.
The calculations are prepared to the Eurocodes, the UK National Annex and Approved Document A, so they satisfy Building Control and can be followed on site. Because a single opening is often the whole scope, We agree a single fixed fee agreed as a fixed price. We serve clients across the UK, delivering calculations anywhere and arranging a site visit by region where the wall needs to be seen first.
What we check.
The points our calculations resolve for a project like this.
- Load above the opening worked out from the masonry, floor and roof bearing on the wall
- Lintel or beam sized to the span and the load, from proprietary lintel to steel section
- Cavity treatment and a separate member per leaf where the wall is cavity construction
- Padstone and bearing design with the bearing stress checked against the masonry
- Pier and load path checked below the beam, with strengthening where the load concentrates
- Temporary propping and a safe order of work while the opening is cut
Issued drawings, redacted.
From enquiry to sign-off.
Enquiry
Send drawings or describe the problem. We confirm the scope, the deliverables and a target timescale.
Information
We agree the survey, drawings or data we need and any site access required.
Engineering
Design, calculation or assessment to the relevant Eurocodes and UK National Annex.
Issue
A clear, defensible report or set of calculations, with assumptions and limitations stated.
Common questions
Do I need a beam for a new window or door?
If the wall is load-bearing, yes. Any new opening in a wall that carries load needs a lintel or beam to pick up the masonry and any floor or roof above. We size it and design the bearings so Building Control accepts it.
What is the difference between a lintel and an RSJ?
A lintel is a proprietary steel or concrete unit for modest openings and loads. An RSJ, or rolled steel beam, is a heavier section used for wider or more heavily loaded openings. We choose whichever suits your span and load.
How much does beam design for a new opening cost?
Our fee for a single new opening and beam starts agreed as a fixed price. The figure depends on the span, the load above and whether one member or a pair across a cavity is needed.
What is a padstone and why do I need one?
A padstone is a solid block under each end of the beam that spreads the load into the wall so the brickwork below is not crushed. We size it from the beam reaction and the strength of the masonry it bears on.
Can you tell me how to prop the wall while it is cut?
Yes. Even on a single opening our package sets out the temporary propping, the support to the wall above and the safe order of work, so the masonry stays held while the opening is cut and the beam is set on its bearings.
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Tell us what you are building.
Send the drawings or describe the project. We confirm scope, deliverables and a realistic timescale.
Start a project