GBR Concrete - Dayton, Ohio

Concrete is made up of stone, water, and cement. The cement slurry on the surface or finish of concrete is porous, those pores allow water intrusion or surface water saturation. This saturation, over time, can begin to deteriorate the cement slurry and begin to expose the stones in the concrete. Areas where the concrete is exposed to below freezing temperatures can accelerate the deterioration. Also, the quality of the original finish of the concrete can determine how strong the surface is and how critical it is to protect the surface as soon as possible after placement.

To prevent the surface of the concrete from deteriorating, the surface needs to be sealed. There are basically two categories of sealers: membrane and penetrating Membrane sealers provide a membrane on the surface of the concrete to protect the surface from weathering, salts, oils, chemicals, etc. As a membrane sealer, the sealer remains on the surface of the concrete and is therefore more subject to wear and protects the surface anywhere from 15-18 months, depending on use. Penetrating sealers penetrate into the concrete sealing the pores providing more long term sealing of the concrete. These sealers also act as a water repellant, causing the water to bead on the surface of the concrete. Penetrating sealers need applied every 5-6 years, depending on use.

Sealing the Concrete

Powerwash the concrete surface, removing loose dirt, bird droppings, etc., let the surface of the concrete air dry and then apply one coat of the sealer with a nap roller. Make sure the first coat is a liberal application of the sealer, being sure to overlap each stroke. Let the surface dry for about 15-30 minutes and then apply the second coat. Keep traffic off of the concrete until it’s completely dry. Note: If you’re not able to do it yourself, GBR provides this service at between $.40-$.50 sq ft—please call for your free estimate.

Sealing Products

There are a couple products available. A penetrating sealer that we use is Dayton Superior Chemical product Weather Worker S-40 (J-29). http://www.daytonsuperior.com/c06_Penetrating06_J-29.html?pcid=162. This product can be purchased from Ernst Concrete at 237-7777. http://www.ernstconcrete.com/ Also, we recommend a product that Ohio D.O.T. is using to seal bridges and overpasses, called ChemTec One. ChemTec One is poured on the concrete and worked into the concrete with a broom until the entire product is saturated into the concrete. The material chemically bonds to the concrete, preventing water penetration. http://www.concretesealer.net/history.htm

Crack-sealing Concrete

http://www.daytonsuperior.com/JointSealantsWaterstops.html

Control joints are intentional lines of weakness placed in the concrete at the time of placement to weaken the concrete in a straight line so when the concrete cracks it cracks in a straight line and the crack is one inch below the surface as to be inconspicuous. The control joints are placed within 6-8 ft apart to insure the best control of cracking. When a crack has formed and weeds begin to grow, the water is now penetrating the surface and steps should be taken to prevent the water penetration. Water penetration will soften the stone over time and, with the weight of a vehicle, begin to allow the slabs to sink.

Prevention

To prevent the water from penetrating the pores, clean out the cracks and install a styrafoam backer rod in the crack down in the control joint, which can be found at any home center. The backer rod should be just slight bigger in diameter than the width of the crack, and then apply self-leveling crack filler on top of the backer rod—to prevent water intrusion. http://www.poolcenter.com/service_supplies_pool_caulking_supplies.htm?gclid=COKHmOm5oJgCFRJdxwod-SsImg Note: GBR also offers this service at $1.50 per linear foot.

Asphalt Preventive Maintenance

Asphalt is made up of tar and stone. New asphalt is very porous, these pores allow water to penetrate between the stones. In the winter the water begins to freeze and expand between the stones, eventually unraveling stones on the surface. To prevent this unraveling, apply two coats of a coal-tar emulsion silica-sand-based sealer to the surface of the asphalt. As well, over time asphalt will begin to crack, once the crack is 1/8” wide, fill the crack with a rubberized tar substance, making sure that water doesn’t penetrate to the stone base.