Archive for the ‘driweway sealing’ tag
Concrete Driveway Sealer – Using It
Easy maintenance and good looks have prompted many householders to go in for concrete driveways. Broom finish is very acceptable but others do go for a more expensive looking exposed aggregate.
It’s the quality of concrete that determines the final outlook and quality of floor. The concrete should have entrapped air. These air bubbles of microscopic size remain embedded in the concrete even after it has been cured. The expansion or contraction of concrete as a consequence of changed climatic conditions is absorbed by these bubbles, thus keeping the concrete free of scaling. Water on entering bricks, concrete or natural stone causes the surface to peel off or pop out. This phenomenon is known as spalling.
Spalling and Scaling Causes
Spalling and scaling points to a deterioration of any concrete surface. The top layer gives way and it peels of in the form of flakes .This causes the stone aggregate to get exposed to outside atmospheric conditions and it worsens with time. As the top layer flakes off, very minute pits are formed. The overall effect is to weaken the concrete. There could be other causes of damages but they all point out to the use of improper concrete. The concrete might have lacked cement content or it had more than required volume of water or insufficient volume of air. The excess of water on getting frozen in winters is expanded. This expansion of trapped water could lead to cracking of top surface of the concrete.
De-icing Salts and Deteriorating Concrete
De-icing salts are added to melt snow and ice. Water formed as a consequence of melting may enter concrete. When the temperature falls below the specified working temperature of de-icing compounds, water will naturally get frozen. The damage is not caused by the salt itself but by expansion caused as a result of frozen water.
As salts melt snow and ice, water enters the concrete. The de-icing salts are responsible for corroding the steel reinforcement that is used in concrete driveways. This causes a further weakness of the concrete used in the driveway.
Penetrating Siloxane Sealers to Protect Concrete Driveways
A visual inspection of the driveway can not confirm if the driveway is good enough to withstand expansion of frozen water. To be safe, you should use a penetrating compound, and those containing silanes and siloxanes are among the best. These break through the surface of the concrete and form a chemical bonding with it. The pores get filled and prevent water from entering the concrete. Further, the concrete can breathe and thus release any trapped water vapor inside it. Water vapors may also travel up from beneath the concrete and in the absence of an escape-route; it remains trapped and on freezing causes spalling and scaling.
Epoxies and acrylics should be avoided as they do not allow the water vapor to escape. The sealers provide fencing to water. They remain invisible and do not color, darken or change the texture of the concrete. If you choose the right sealer and follow the rules when sealing, you will get a long lasting and great looking surface.