Sealing concrete in cold climate
The proper use of concrete sealers in cold climates is essential to maintaining a professional look. High quality sealers can offer resistance to chipping, pitting, flaking and spalling that is often the result of extreme freeze-thaw conditions. When there is a high level of surface water on the sealed area, it can effectively break down the sealer over time, and turn any colored concrete to an unappealing shade of white. Additionally, the emission of water that is trapped underneath low-quality sealers will over time create an unattractive appearance. The only sure way to handle freeze-thaw conditions and avoid many of the pitfalls of improper sealing is to develop a strategic plan.
A Strategic Plan
The initial step in maintaining a quality professional look on the top of any sealed concrete is to develop the battle plan. It is imperative to avoid relying on the concrete company, even those that offer air-entrained concrete, which has a natural resistance to the damaging effects of freeze-thaw cycles. In the end, this special concrete does not provide enough protection to maintain a professional-grade appearance.
In the Short Term
An effective strategic plan includes protection for both the short term and the long term. In the short term, it is essential that the concrete sealer is applied only when the exterior temperature is 50° or higher, and on the rise. Because of that, any late-season work will often go unsealed until the warm weather returns. Part of the plan should include having detailed instructions for the customer to avoid using any de-icer through the winter months until the concrete can be sealed properly in the warmer days of spring.
In the Long Term
The long-term portion of the plan involves effective concrete placement. It is important to maintain the freshly poured ready mix to a point where it is wet enough to offer the necessary workable material during the placement procedure. This requires maintaining one-quarter inch per foot of slope, especially if there will be an imprint in the surface.
The slope is critical because standing water will often puddle in the lower areas of the imprint, with or without sealing. The concrete will need to cure for at least a month before proper sealing can be applied. Before the application of sealing, the surface of the newly poured concrete must be thoroughly cleaned using pressurized water. The surface of the concrete will need to dry thoroughly overnight after cleaning, before the application of the sealer.
It is crucial to ensure that all of the irrigation sprinklers and downspouts from the roof avoid wetting the concrete surface prior to applying the sealer.