APPLICATION INSTRUCTIONS ADDENDUM

For

WINTER FIREPROOFING APPLICATION

Special precautions are required when applying fireproofing under winter conditions. Some of the more critical items are discussed briefly below.

1. Temperature of the steel substrate could be to low for fireproofing application. Any water based material sprayed onto substrates near freezing temperature will probably form a thin layer of ice on the steel before the fireproofing sets. When this occurs, there will be a lack of bond. This is one reason for the 40⁰F temperature limitation on spraying conditions.

Both air and substrate temperatures of at least 40⁰F (4⁰C) must be maintained for 24 hours before and after application of a fireproofing material.

2. Increased drying time is common for the simple reason that air absorbs and retains moisture in direct relation to the temperature. Colder air will absorb smaller amounts of water and require longer drying times.

3. Lack of adequate ventilation is also a very common problem in cold weather because many buildings are closed tightly to retain heat. However, drying requires ventilation.

If air changes through ventilation are not provided the air becomes saturated and the drying process stops. Saturated air must be continuously removed and replaced with fresh, warm, dry air.

A common mistake is to use air circulation with fans rather than provide real ventilation. Circulation only moves wet air around and does not provide the necessary drying. The standard industry definition of adequate ventilation is not less than four complete air changes per hour.

End of Addendum 2/2005

Southwest Fireproofing Products Company, Albuquerque, NM 87107 Phone: (505) 345-1633

©2004 Southwest Fireproofing Products Co.

Southwest Fireproofing, Type 5GP, Type 5EF, Type 5MD, Type 7GP, Type 7HD, Type 1XR, Type DK, Type HC and Type 7TB

are trademarks of Southwest Fireproofing Products Co.