How to Choose the Right Sealant for Asphalt Drive
QUESTION: During the home inspection, the inspector recommended resealing the asphalt driveway if I buy the house. After moving in, I received three bids from paving companies and was surprised at the wide range of prices and the selection of sealant offered. The highest bidder recommended oil-based sealant, while the lowest bidder said that slurry is just as good. If that’s not confusing enough, my neighbor said I can do the job for half the price of the lowest bid if I buy the slurry at a local building supply and simply do it myself. I’d love to save money, as long as the quality doesn’t suffer. How should I approach this dilemma?
ANSWER: There are three types of sealant commonly used to resurface asphalt pavement: oil-based sealant, coal tar, and water-based slurry.
The type most often applied by do-it-yourselfers is slurry, an asphalt and cement mixture, which can be applied in the same way as paint, with a roller or broom. This method is relatively simple and inexpensive, but slurry is not the material of choice if you’re seeking a long-lasting, high-quality finish.
Slurry is low in oil content and tends to dry out, crack and peel within one to two years of application. This means that resealing is generally needed at more frequent intervals than with other types of asphalt sealer. And once slurry begins to peel, it provides poor adhesion for subsequent layers of sealant.
The product of choice is oil-based sealer because it achieves more complete penetration and adhesion to old, rough asphalt surfaces and typically lasts several times as long, usually four to six years, depending on weather conditions.
Coal-tar sealant is rapidly disappearing from the marketplace because it has been found to be environmentally hazardous. In some states, including California, it is no longer legally available, although a few containers may still be lurking on the shelves of old hardware stores.
Resealing asphalt driveways the do-it-yourself way is better than doing nothing at all, but professional application of oil-based sealant is the best way to prolong the useful life of your driveway.
Correct Color of PVC Pipe Can Be Crucial
Q: During a recent home inspection, the inspector found that underground wiring from my house to my workshop is encased in white plastic PVC pipe. The buyer insists that I replace the power lines using gray plastic conduit. Please explain what difference it makes if the conduit is white or gray--or purple for that matter.
A: To illustrate the problem with white PVC conduit, let’s suppose that your plumber is repairing a sprinkler system in your back yard. He excavates what he believes to be a PVC water pipe and cuts into it with a hacksaw.
Surprise! Your plumber has just dissected a set of 220-volt wires, and is now reclining rigidly beside the rose bushes. Time to call 911.
To prevent mishaps of this nature, the building code specifies gray plastic conduit as a means of easy identification, to protect tradespeople from needless injury. Plumbers and electricians are familiar with this system of color-coding and rely upon it for their own safety.
Accordingly, white pipe denotes water, gray indicates electrical wiring, and yellow is used exclusively for gas.
The use of PVC plumbing pipe for electrical wiring is a commonly practiced code violation, occurring when homeowners and other handymen take it upon themselves to perform the work of licensed professionals. Color-coding prevents serious injury and violations of these codes can lead to harmful situation. Compliance with your inspector’s mandate is highly recommended.
Got a question about any aspect of the home inspection? Send it to Barry Stone, Los Angeles Times, 540 Atascadero Road, Morro Bay, CA 93442. Queries can also be sent via e-mail to: inspector@fix.net.