Draft block system

Year	Description
2001	Invention patented by Fred E. Hovenier on April 26th, 2001. Abstract: A draft block joist system for preventing an airflow circulation therethrough. The system comprises a first and second elongated I-beams each having continuous upper and lower flange sections with a panel member disposed therebetween. The upper and lower flange sections of the first elongated I-beam are respectively connected with the upper and lower flange sections of the second elongated I-beam. An air gap is formed between the panel members of the first and second elongated I-beams thereby. By forming the air gap, an insulation member is removably insertable therein for preventing the airflow circulation therethrough.
Source: selected by the editor from original sources.

Invention: Draft block system