Damper

A baffle used to open or close the throat of ventilators.

Dead Load

The weight of the Building System construction consisting of members such as framing and covering.

Dealer

A party who, as a routine part of his business, buys Metal Building Systems from a manufacturer for the purpose of resale.

Deflection

The displacement of a structural member relative to its supports due to applied loads. Deflection should not be confused with “Drift”.

Design Loads

The loads expressly specified in the contract documents which the Metal Building System is designed to safely resist.

Design Professional

The Architect or Engineer responsible for the design of a Construction Project.

Diagonal Bracing

See “Bracing”.

Diaphragm Action

The resistance to racking generally offered by the panels, fasteners, and members to which they are attached.

Direct Tension Indicator

See “Load Indicating Washer”.

Door Guide

An angle or channel used to stabilize or keep plumb a sliding or rolling door during its operation.

Downspout

A conduit used to carry water from the gutter of a building.

Drift (Sidesway)

Horizontal displacement at the top of a vertical element due to lateral loads. Drift should not be confused with “Deflection”.

Drift (Snow)

The snow accumulation at a height discontinuity.

Drift Pin

A tapered pin used during erection to align holes in steel members to be connected by bolting.