Padstone and bearing design
A padstone spreads the concentrated reaction from a beam or lintel into the wall below so the masonry is not crushed. We design padstones and bearings to the Eurocodes for beams and lintels across the UK.
What is a padstone for?
A padstone spreads the concentrated reaction from a beam or lintel over a larger area of wall so the masonry underneath is not crushed. Without one, the load arrives at a single point and can overstress the brick or block directly below the bearing.
Why a padstone is needed
When a steel beam lands on a wall, its entire reaction arrives at a single point over the width of the beam's bearing. Masonry is strong in a spread compression but weak under a concentrated load, so without a spreader the brick or block directly under the beam would crush. A padstone is a dense concrete or engineering brick block that receives the beam and distributes the load over a larger area of wall, bringing the bearing stress down to what the masonry can safely take.
The design is a check of bearing stress. We take the beam's design reaction, spread it through the padstone at the code dispersal angle, and compare the stress at the top of the masonry against its bearing capacity to BS EN 1996-1-1, the masonry Eurocode. The masonry capacity depends on the unit strength and mortar, so the padstone size is not a standard block; a heavier reaction or weaker wall needs a longer or deeper padstone, and we size it to suit rather than defaulting to a token 100mm block that does not do the job.
Sizing the padstone and checking the wall below
Padstone length along the wall is usually set by the beam's web bearing and buckling requirement, so the two checks are done together, the steel and the masonry, because the same bearing length appears in both. The depth of the padstone controls how far the load spreads before it reaches the masonry, so a taller padstone can reduce the stress on a weak wall. We specify the concrete grade, often a precast dense unit or a cast in situ pad, along with its plan dimensions and depth.
A padstone solves the crushing at the top of the wall, but the load then travels down through the masonry, or the pier, to the foundation. We check that the wall or pier below the bearing can carry the accumulated load without overstressing, and that the load reaches an adequate foundation. Where the bearing sits on a narrow pier between openings, that pier often governs, and we may need to widen it, add a column, or take the load down on a dedicated pad. Ignoring the wall below is a frequent oversight: a correct padstone above a failing pier still fails.
Detailing, buildability and coordination
The padstone has to be built into the wall as the beam is installed, so the detail must be practical. We show the padstone level, its bedding on full mortar, and how the beam sits and is packed, avoiding a bearing on a single high spot. Where a beam bears near the end of a wall we check the edge distance so the load does not spall the corner, and where two beams bear close together we may combine them onto one padstone.
Padstone design is rarely a standalone job; it comes with the beam or lintel it supports, and we issue it as part of that package so the whole load path is consistent from beam reaction to foundation. The output states the padstone material, size, bedding and position at each bearing, ready for the builder and Building Control. We deliver these calculations anywhere in the UK, with a site visit arranged by region where the existing wall needs assessing before a bearing is confirmed.
What we check.
The points our calculations resolve for a project like this.
- Beam or lintel design reaction as the concentrated load to be spread
- Bearing stress at the top of the masonry checked to BS EN 1996-1-1
- Padstone length coordinated with the steel web bearing and buckling requirement
- Padstone depth set to disperse the load onto weak or narrow walls
- Capacity of the pier or wall below the bearing down to the foundation
- Edge distance and bedding so corners do not spall and the bearing is even
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
What is a padstone for?
A padstone spreads the concentrated reaction from a beam or lintel over a larger area of wall so the masonry underneath is not crushed. Without one, the load arrives at a single point and can overstress the brick or block directly below the bearing.
How big does a padstone need to be?
It depends on the beam reaction and the strength of the wall beneath. We check the bearing stress to the masonry Eurocode and size the padstone accordingly. A heavier load or a weaker wall needs a longer or deeper padstone, so there is no universal size.
How much does padstone design cost?
When designed with the beam it supports, padstone design is usually included in that package. As a standalone calculation our fee starts agreed with you before we begin.
Can I just use a standard concrete block as a padstone?
Sometimes, but only if it has been checked. A token block that has not been sized against the actual reaction and wall strength may not spread the load enough, and the masonry can still crush. We confirm the correct material and size for your specific bearing.
Do you check the wall below the padstone too?
Yes. The padstone stops crushing at the bearing, but the load still travels down through the wall or pier to the foundation. We check that the masonry and pier below can carry it, since a correct padstone over a failing pier still fails.
Related in structural design & elements.
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