Self-leveling Overlay Cement

Use Self Leveling Overlay To Fix That Ugly Concrete

If you want to cover-up an unsightly concrete surface without resorting to extensive repair work, consider the use of a self-leveling overlay cement free flowing mortar. It is easy to apply, does not require the use of a trowel and is ready to walk on in only 4 to 6 hours.

There are basically four types of overlays:

• Stampable
• Micro-toppings and skim coats
• Spray-down systems
• Self-leveling

Self-leveling is a self-smoothing polymer modified cementitious topping that can reconfigure uneven concrete, correct camber problems, resurface scaled concrete and fill depressions and sags. It bonds quite well with high adhesive strength provided the sub-flooring is properly prepared.

Some old concrete is not suitable for an application of overlay. Without being structurally sound and no appearance of severe cracks, the adhesion will be less than satisfactory. Any non-structural cracks must be repaired adequately, otherwise bonding will be limited.

The application of self-leveling cement overlay requires no special skills, tools or additives. You simply mix the material with water using a mechanical mixer, pour and spread it into place and leave it to harden. Because these overlays are typically applied at thicknesses of 1/4 inch or greater, they effectively cover minor flaws and compensate for height variances.

No troweling is required, unless you plan to feather-edge at the perimeter of the pour. Sub-floor high spots should receive a minimum 1/8 inch cover and make sure you do not retemper material which has begun to set. Finally, you should discard any material that you don't use within 20 minutes of mixing.

One welcomed feature is that the final product is water resistant and does not tend to "dust up" through carpeting or crumble upon contact with moisture. And, since it is a cement based composition, it builds strength up to 5800 psi, which matches higher quality concrete. Plus, it contains no toxic resins, solvents or diluents and is odorless, non-flammable and non-corrosive.

Your completed concrete overlay can be left seamless (except at control joints) or used as a canvas for saw-cut or engraved designs. You can even incorporate decorative inlays, such as strips of wood or metal, by fusing them to the base concrete and then pouring the overlay to the level of the inlay. You can also enhance the final appearance by staining or dying.

Self-leveling concrete overlays are usually applied at thicknesses of no less than 1/4 inch. This makes them heavier than comparably thinner overlays or toppings, so be sure that any flooring is structurally sound and able to bear the extra weight... especially if going over wood. Also, these are less flexible after drying than micro-toppings and spray-down systems, which increases the risk of cracking.

Unlike straight cement, it does not require extended moist cure. In fact, most placements require no special curing. However, if working in hot, dry, or windy conditions, it is recommended that you apply some misting to the surface during the first 1 to 3 hours after the pouring. This helps to avoid premature drying. After this initial period, simply allow it to dry cure.

Self-leveling concrete overlays are becoming very popular with architects, designers and homeowners. Just because concrete is worn and aged doesn't mean that it can't be topped with a fresh, level canvas to decoratively match any decor. Overlays can be as thick as several inches, or paper thin. And, they can be used both indoors and outdoors.