Silent Floor Joist Specifications

Silent Floors

• In 1969, the Trus Joist Corporation introduced the first wooden I-joist. According to the University of Massachusetts, Trus Joist responded to homeowners who wanted larger floor plans in their homes, but who could not depend on industry-standard joists to support longer expanses. The Weyerhaeuser Company uses Trus Joist’s original technology in their Silent Floors joists. Silent Floors are made of engineered lumber instead of sawn lumber, which gives them strength and stability qualities that eliminate noisy floors.

Wood

• According to Trus Joist’s “Silent Floor System Field Guide,” sawn lumber inconsistencies are the primary cause of squeaky floors. Size, strength, moisture content and varying wood grains vary from one sawn board to another. Silent Floor wood specifications call for engineered lumber instead of sawn lumber, which provides uniformity in joist construction and installation. Tim Carter of AskTheBuilder.com explains that structural engineers figure specifications for joist depths, and this is not a task for the average homeowner. With joist depths of 10 to 16 inches, Silent Floors accommodate different horizontal spans and load-bearing capacities.

Hardware

• Hardware specifications for Silent Floor joists include guidelines for hangers and nails. Hangers form the support system that holds joists together. Structural engineers calculate proper sizes for hangers so that joists fit securely without leaving gaps. Gaps allow movement when weight is applied and will cause the floors to squeak. “The Silent Floor System Field Guide” cautions against improper nailing. If sheathing nails are not driven solidly into joists, but barely skim the outside, they cannot hold joists firmly. When weight is applied by walking on floors, they will squeak.

Bracing

• The City of Waupaca’s “Framer’s Pocket Guide to the FrameWorks Building System” outlines specifications for proper lateral bracing. Joists are unstable until all bracing components are in place, including blocking, hangers, sheathing and rim boards. The “Specifier’s Guide” warns that without proper bracing, joists may roll or buckle even under light loads. The Guide recommends nailing safety bracing lines to end walls or sheathing and to each joist to stabilize loads and provide lateral strength.