Steel Column Cap Plate: Types and Benefits for Construction

The plate at the bottom of a steel column is called a base plate. Its primary function is to transfer the axial load from the column to the concrete foundation or footing it rests upon. The base plate is typically larger than the column's cross-section to spread the concentrated load over a wider area, ensuring the pressure on the foundation does not exceed its bearing capacity.

A steel column base plate is a thick steel plate welded to the bottom of a column. It distributes the column's load to the foundation, preventing the column from punching through the concrete. It is anchored to the foundation using anchor bolts, securing the column's position and providing resistance against uplift and shear forces. The design and thickness of the base plate are engineered based on the column load and foundation strength.

WEATHERCAP® is installed over the sealant in a masonry joint, shielding it from direct exposure to UV rays, rain, and extreme temperatures. This protection significantly extends the life of the sealant and prevents premature drying, cracking, and margin checking. Its soft lead material also accommodates building movement, reducing stress on the sealant bead and maintaining a weather-tight seal for longer.

Type A is a flat-cap configuration designed for masonry joints where the two surfaces are in approximately the same plane, such as on top of copings or across belt courses. Type B is a 90-degree cove-cap configuration used for right-angle joints, such as where a horizontal cornice meets a vertical wall or at the perimeter of a window sill. The choice depends entirely on the geometry of the joint.

Yes, it is ideal for historic restoration. The system is specified in the U.S. General Services Administration (GSA) Historic Preservation Technical Procedures. Its ability to accommodate movement in older structures while protecting joints makes it a trusted solution for preserving landmark buildings. It has been successfully used on numerous national landmarks, including the Washington Monument and the U.S. Supreme Court building.

All WEATHERCAP® products, including both Type A and Type B configurations and all available sizes, are supplied in standard 6-foot lengths. This allows for convenient handling and transportation to the job site. The lengths can be easily cut and fitted in the field by contractors to match the specific dimensions of the masonry joints they are protecting. Materials are typically shipped within 48 hours of order placement.