I-Joist Floor Details for 2-Inch-Thick Foundation Foam Insulation

Building codes in some northern climate zones require that concrete or CMU (block) foundations be insulated. Foundation insulation presents a deviation from typical rim board details as published in APA Performance Rated I-Joists, Form Z725, causing alignment issues between the walls and the supporting rim boards.

This publication is designed for: architects, engineers, designers, builders

This publication presents four construction details that are known to be used in some norther states.

Key sections include:

• Two-inch thick exterior foundation foam insulation using 2x3 or wider rim block with joist framing perpendicular or parallel to foundation

• Two-inch thick exterior foundation foam insulation and 11/2-inch-thick rim board foam insulation using discrete vertical block with joist framing perpendicular or parallel to foundation

• Two-inch thick exterior foundation foam insulation and 2-inch thick rim board foam insulation using extended sill plate with joist framing perpendicular or parallel to foundation

• Two-inch thick exterior foundation foam insulation using vertical block (elevation view)

Published by APA — The Engineered Wood Association.