The Dangers of Building in Cold Weather
Builders and homeowners alike are concerned about building during winter months, particularly in cold climates where the temperature is routinely below freezing for much of the winter. This article will cover issues surrounding the pouring of concrete foundations in cold weather.
If the proper building construction techniques are not followed, concrete will not cure properly causing potential problems later on such as cracking and dusting. Not only will you reduce the strength of the concrete, dusting may occur and cause possible indoor environmental problems later for the homeowner. We also recommend that homeowners seal any exposed concrete walls with a good quality concrete sealer to reduce the effect of concrete dust on household air quality.
This article will discuss some of the steps homeowners and builders should take when considering constructing a home during the cold winter months.
The Basics:
In order for concrete to cure properly, temperature minimums and moisture levels must be managed during the curing cycle to ensure that proper 28-day strength characteristics are achieved. Cold weather concreting requires special steps to ensure that the concrete does not freeze and also does not dry too rapidly during dry winter months.
Prior to pouring concrete in winter months, builders must plan for proper equipment, manpower, weather protection, and appropriate concrete mix with accelerating admixtures and heated mixtures to help develop early concrete strength. All snow and ice must be removed from concrete forms and the sub-base prior to pouring concrete and all items that come in contact with concrete should be not be below 32 degrees Fahrenheit.
Special Requirements:
Concrete pouring and curing must be managed in cold weather situations. The cost of winter construction with the additional requirements identified below must be compared to delays until warmer spring or summer temperatures. Special attention must be given to the following:
Always ensure that concrete has properly cured.
Do not allow concrete to prematurely dry out.
Keep Ice from forming to allow proper hydration.
Use insulation blankets or heaters.
Avoid direct contact with heaters to avoid dusting.
Ensure heaters don't run out of fuel and avoid fire hazards.
Remove heat protection slowly to prevent rapid cooling.
Triple insulation at corners and edges of walls.
Leave forms in place long enough to prevent rapid drying.
Ask your builder to explain the steps he will take to ensure a high-strength, properly cured concrete foundation and floor.
Municipal Code Requirements:
Many municipalities or state agencies have specified technical requirements for cold weather masonry construction covering temperature conditions below specific temperatures, often at 41 degrees F, or 5 degrees C. Your concrete subcontractor should be well aware of these requirements and should be able to demonstrate to you the steps they will take to ensure that these requirements will be met.
For more detailed information, we have provided links to several web sites that provide addition information about concrete in general as well as about pouring concrete in cold weather conditions.
Useful Resources:
