Plan Now for a Frosty Forecast

Brrrr . . . it won’t be long before the cold winds blow and the temperatures drop, both of which have special concerns for those of us in the construction industry. There are important procedures to follow to prevent costly consequences.

Concrete

The American Concrete Institute, in its ACI ACI 306.1-90, "Standard Specification for Cold Weather Concreting," defines cold weather as: “A period when for more than three successive days the average daily outdoor temperature drops below 40 F. The average daily temperature is the average of the highest and lowest temperature during the period from midnight to midnight. When temperatures above 50 F occur during more than half of any 24 hour duration, the period shall no longer be regarded as cold weather."
To accommodate those temperatures, concrete must be properly manufactured, placed and protected. Follow all cold weather concreting recommendations as listed at www.ccagc.org/pdfs/ACI_306R-88_Cold_Weather_Concreting.pdf

Masonry

The Specification for Masonry Structures (ACI-530, 1-95/ASCE 6-95/TMS 502-95) considers cold weather construction to exist when ambient temperature falls below 40 degrees F. As the temperature of mortar materials falls below normal, the temperature of mortar is lowered when it is placed in contact with cold masonry. This creates slower reaction rates between the cement and water, reduces strength gain rates, and delays tooling and setting times. Disruptive expansion of the mortar may also occur if the water in the mortar freezes, and, should the surface become wet or ice-covered, it may prevent a good bond from forming between the mortar and the masonry unit. Follow all cold weather masonry recommendations listed at http://www.maconline.org/tech/construction/cold1/cold1.html

Frost can impact excavations, foundations and slabs, causing uplifting heaves and potentially challenging structural integrity. Remember to make preparations to:

Protect excavations for foundations and interior utilities from frost.
Protect subgrades for slabs on grade from frost if they will be enclosed prior to spring thaw.
Protect shallow interior footings, and slabs on grade from frost until the building is enclosed and has temporary heat.
Protect all foundations from frost until backfilled.

Call me at 627-6873 or send an email to tom@zugassociates.com to discuss plans for your building or project.