Padstones
(6 Products)Padstones are high-strength precast concrete blocks designed to distribute concentrated loads from beams and lintels into supporting masonry. Essential for structural stability, these dense units range from standard rectangular profiles to square-face dimensions, ensuring effective weight spread across brick or blockwork to prevent local crushing.
Understanding Padstones
Precast concrete padstones are engineered to accept and transfer high point loads from structural members, such as steel beams (RSJs) and concrete lintels, into the building fabric. Unlike standard masonry units which may crack or crush under intense pressure, these dense blocks are manufactured to a high compressive strength, ensuring the load is safely dispersed into the wall below.
The primary function of a padstone is to act as a load-bearing intermediary. By increasing the bearing area at the junction of a structural support, they mitigate the risk of structural failure, spalling, or cracking in the standard masonry. This is particularly critical where heavy steelwork rests on lower-density concrete blocks or hollow bricks.
These ready-made units provide a consistent, fully cured solution that eliminates the variability and delays associated with casting concrete on-site. Their dimensions are specifically designed to course with standard masonry sizes, ensuring seamless integration into the wall construction without the need for extensive cutting or adjustment.
Material Range
- Standard Width Padstones (100mm): Designed to sit atop standard 100mm load-bearing walls. These units fit flush with the inner leaf of a cavity wall or internal partition, providing a robust bearing surface for lintels without disrupting the wall finish.
- Wide Wall Padstones (140mm & 215mm): Larger units engineered for thicker wall constructions or heavy-duty applications. These are essential when the bearing area must be maximised to handle higher loads from large steel beams or girder trusses.
Performance Benefits
- High Compressive Strength: Manufactured to withstand significant vertical pressure (typically 50 N/mm²), providing a robust base for structural steel.
- Effective Load Transfer: Distributes concentrated weight over a wider surface area to prevent masonry failure.
- Immediate Application: Pre-cured and ready for installation, removing the downtime associated with on-site casting.
- Versatile Sizing: Available in both rectangular and square profiles to match specific wall courses and beam seating requirements.
Typical Applications
- Steel Beam Support: Bedding beneath Universal Beams (UB) and Universal Columns (UC) at wall junctions.
- Lintel Bearings: Supporting the ends of heavy precast or prestressed lintels.
- Truss Bearing: Distributing loads from heavy timber roof trusses onto the supporting wall plate.
Specification & Standards
- BS EN 771-3: Specification for masonry units (Aggregate concrete masonry units).
- CE Marked: Compliant with relevant European construction product standards.
Related Materials and Construction Uses
Padstones are typically bedded onto the masonry using a high-strength engineering mortar to ensure a solid, void-free connection. They function as the primary seating for structural steelwork, often working in conjunction with slate packing or non-shrink grout to achieve a perfectly level bearing surface for the beam or lintel above.
Frequently Asked Padstones Questions
What Does Cast In-Situ Mean?
Cast in-situ, otherwise known as cast-in-place concrete, refers to a process in which a building's structural components are poured, moulded and cured at the site in formwork.
With precast concrete, however, slabs are cast on a different site and are instead, delivered to the construction site before their assembly.
What Is Better: Precast Concrete Or In-Situ Concrete?
Precast concrete tends to be more durable than cast-in-place concrete. The carefully monitored curing process of precast concrete sets the seal on the quality of the product's finish.
Another factor which lends itself to precast's supremacy is the lack of disruption from external factors such as weather conditions. With in-situ concrete, you have to be wary of rain, hail and other elements which may serve to harm the final form of the casting.
How Are Pre-Cast Padstones Manufactured?
Precast padstones are created by combining specific proportions of aggregates, cement, and water, which are then poured into moulds. To further enhance the properties of the final product, additional materials such as prestressed cable reinforcement can be added to increase the concrete’s strength.
After moulding, the padstones are cured in a carefully controlled environment to ensure optimal performance and durability.
