Winter is soon upon us – it’s December and temperatures are starting to dip closer to freezing. Pre-cast concrete steps are resilient and long wearing, but take some precautions when it comes to winter conditions and the steps you take to combat them. Namely, salt in all it’s forms. As you are aware, use of salt voids the warranty on our products, but let’s talk about why and some helpful tips about concrete steps and winter conditions.
Damage due to Salts
We know salt mostly as table salt (NaCl), but salt can take many other forms. For deicing uses the common salts for deicing are sodium chloride, calcium chloride, potassium chloride and magnesium chloride. Home with pets may be familiar with “pet friendly” salts based on urea diamide. Consumer Reports has a great chart listing the properties of each salt. One of the common properties among all these de-icers is that they all damage concrete. This can be through multiple causes:
- Physical damage – chlorides lead to crystal growth within the concrete pores
- Chemical damage – calcium chloride and magnesium chloride react with the concrete leading to chemical changes in the paste leading to reduction in strength
- Corrosion – Leaching of of chlorides into the structure of the concrete can attack the steel reinforcement. Corrosion of the rebar causes expansion of corrosion products and changing mechanical stresses. This leads to formation cracks and spalling.
- Increased freeze/thaw cycles – when melted ice water enters pores and refreezes at a lower temperature causing damage from expansion
In summary, regardless of the pathway of damage, the key message is that use of deicers can result in loss of material, reduction in strength, and shorten the life of the product.
Concrete Steps and Winter Conditions Best Practices
As we prepare for winter, lets talk about the best way to clear snow and ice off concrete steps. Our pre-cast steps are textured to provide plenty of traction if the steps are kept clear. Just keep these tips in mind:
- Pre-cast concrete steps should be frequently shoveled (or swept if you’re so lucky with snowfall amounts).
- If traction aid is required, sand may be used. Beware of traction aids that contain ammonium sulfate as sulfates can attack concrete. However, as long as the steps are kept clear, this shouldn’t be necessary.
- If salting other areas (driveways, walkways) ensure you are mindful of not pushing salt towards the concrete structures in use. Make sure you keep this in mind with other products (i.e. culvert ends).
- If ice accumulation is an issue (i.e. downspout run off), electrical stair treads may be used to promote melting/evaporation of ice and snow.