Concrete sealing can be done by either a professional or the homeowner. A professional is going to cost more, since he is being paid for labor, but because he buys his material at a bulk discount, the cost may not be all that much different. In addition, the homeowner must buy appropriate tools. This will not be a cost factor when the concrete is sealed again.
A variety of tools and material is involved in sealing concrete. All prices given are as of October 2011. A concrete driveway first has to be cleaned of all the dirt and oil stains, and any cracks or pits must be filled in. A driveway cleaner for oil stains runs about $20. Stiff bristle brushes are about $5, and a long-handled brush for general washing is about $20.
The material to fill cracks, pits and eroded areas runs from $50 to just over $100, depending upon which style of filling you choose. Sealant is either water- or solvent-based, with the water-base better for areas of greater moisture. The sealant itself ranges from just over $100 to $150 for a 5-gallon pail. Five gallons normally cover about 350 square feet. A squeegee roller costs between $50 and $100, depending upon the type and size.
A professional sealant job runs between 50 cents to a dollar per square foot. Cost factors include the condition of the driveway and the seasonal work load. If you call when the sealer has less work, he might be more willing to negotiate a price reduction. If you take bids from several companies, be sure to compare the materials they are using to see if that makes a difference in the prices.