The constant downward force exerted on a structure by its own weight. This includes the framing, roofing, flooring, drywall, and any permanently installed machinery like HVAC units. Engineers calculate this baseline weight before factoring in temporary forces like snow, wind, or human occupancy.
The dead load on that roof truss increased significantly when they switched from asphalt shingles to slate.
Upgrading building materials during a renovation often changes the dead load, which can require structural reinforcement if the new materials are heavier.
Also heard as
- Static load
Do not mix it up with
- Live load: Dead load is the permanent weight of the building itself, while live load is the temporary weight of people, furniture, and weather.
Related terms
Live load
The temporary or moving weight that a structure must be designed to support.
Design load
The maximum combination of forces a structure is engineered to safely support.
Snow load
The downward force exerted on a building by accumulated snow and ice.
Static load
A constant, stationary force applied to a structure over an extended period.