Just Like New: Concrete Resurfacing
While concrete is an extremely durable material, over time it can be subject to weathering and damage just like any other surface. Especially if the concrete was improperly poured or not sealed during initial construction, the appearance can seriously degrade over time.
Concrete resurfacing can offer an inexpensive, do it yourself option to homeowners looking for a new surface without the hassle of installing an entirely new concrete slab. Breaking up a concrete surface, even if it is a thin slab, can be very time consuming and backbreaking work. If you are looking to refresh a concrete surface in your home, here are some tips on how to ensure a pleasant final result.
Uses of concrete resurfacing
While concrete resurfacing can work on many surfaces, it may not be the best option for every project. Serious holes or cracks should be repaired prior to resurfacing. It is unadvisable to use the thinner resurfacing mixture for thicker areas. Also, a large hole or crack can indicate a structural issue that may need to be addressed by a concrete professional.
Concrete scaling is a common issue that causes people to consider resurfacing. The term scaling refers to an issue where the top, smooth layer of concrete separates from the concrete base, revealing the stones and aggregate in the mixture. This can result in an uneven and unattractive appearance. Serious scaling can indicate an issue with the original concrete construction. A concrete resurface mix may not adhere properly to the concrete base or the concrete may continue to deteriorate underneath the concrete top layer.
Concrete mixtures for resurfacing
Concrete resurfacing generally involves applying a thin layer of concrete, less than one inch thick. For this type of surface, a mixture of portland cement, medium to coarse sand and water will give the desired consistency. A general rule of thumb is to use a 3:1 ratio of sand to portland cement, then just enough water to make the mixture resemble mortar.
If a thicker surface is required, a larger aggregate is needed in addition to the sand, such as pea gravel. In that case, the most common recommendation is for a mixture of 3 parts gravel, 2 parts sand and 1.5 parts portland cement, again with enough water for the mixture to resemble a rough mortar.
If you want to avoid mixing your own cement, many building supply stores sell premixed resurfacing cement in bags or buckets. Ensure that the product you buy can handle the depth you require. Most premixes are thinner mixtures that may not be able to support a depth greater than one-half to one inch. If you need a thicker resurface depth, the best option is probably to mix your own concrete.
Applying a concrete resurface
Surface preparation is critical when applying any top layer to concrete, whether it is a fresh layer or a sealant. Remove all loose concrete, including around any holes or cracks. Consider repairing deep or large cracks and holes well in advance to ensure they dry properly before applying the new surface. Clean the entire surface area, using a pressure washer and/or a specialized concrete cleaning product.
If you are working on an exterior surface, try to pick a day that is expected to be dry and around 50 to 60 degrees Fahrenheit. If the site is not protected from sun or wind, an overcast day that is not expected to be windy would be helpful. Also, since concrete can take a few days to properly dry even when applied in a thin layer, the next few days should be temperate and dry as well.
Once the concrete is clean and your resurfacing material is mixed, dampen the original concrete surface, then apply a thin layer of cement paste to ensure maximum adherence. Apply the resurfacing mixture evenly over the entire surface to the required depth, smoothing it out with a trowel afterwards. Once the concrete has properly dried, apply a concrete sealant to ensure the new surface remains fresh and attractive for many years to come.