Dear James: I have an asphalt driveway, and it has several potholes and large indentations. What is the best method to fix these spots myself? I do not have any method to heat the patch materials. — Mark R.
Dear Mark: You have been doing your homework. When dealing with any asphalt materials, heating it, so that it becomes pliable, is the absolute best method. This is the method that professionals use and your street repair crews use. It is also the quickest pothole repair method. Within a very short period of time, it can be driven on.
When doing the job yourself, you are limited to using a cold patch asphalt repair material. If you have talked to any old-timers about making this repair yourself, you have probably heard that a cold patch repair will not last longer than a year or two.
Up until several years ago, this was true. Now there are new do-it-yourself cold patch asphalt repair materials that will hold up almost as well as professional hot asphalt patch repairs. These take longer to fully cure and harden, up to several weeks, but you can drive on some of them much sooner.
You should be able to find the newer cold patch materials at most building supply outlets that sell bricks, cement, mortar or at some larger home centers. Here are some manufacturers to look for — EZ Street Co., www.ezstreetasphalt.com; Unique Paving Materials, uniquepavingmaterials.com; and PLM Corp., plmcorporation.com.
As with most do-it-yourself home projects, the key to a successful asphalt driveway patch is proper preparation in addition to the proper repair materials. For a pothole or an indentation, first dig out all the bad asphalt. Two inches is an excellent depth to dig, but go as far down as you have to.
Read the instructions on the cold patch container carefully. Most recommend that the sides of the hole to repair should be as flat and vertical as possible. Use a hammer and a chisel to carve the sides of the hole. Clean out all of the debris. If you or a neighbor has an air compressor, blow out the hole when you are done. Always wear safety glasses when doing this.
Since the ideal patch thickness is 1.5 to 2 inches deep, you should fill a deeper hole with gravel to bring the depth to 2 inches. Always use angular crushed gravel, not round or pea gravel that continually moves and will not form a stable base for the patch. Small crushed gravel is available at most building supply outlets and some landscaping companies.
The gravel must be compacted. You have two options for this — a rented steel tamper or an old 4×4 wooden post. If you are working by yourself, a steel tamper is lighter and easier to use. If you have a helper, lifting a long 4×4 post and letting the end drop repeatedly on the gravel works great to compact it.
Fill the hole with the cold patch material, making sure that there are no voids at the bottom of the hole. Mound it up about 1/4 to 3/8 of an inch above the final surface height. Use the steel tamper or 4×4 post again to compact the patch material. This should bring it very close to level with the surrounding asphalt.
Cold patch material begins to cure and get hard when it is exposed to the open air. This curing process can take up to 30 days for the entire depth of the patch to cure. It is important not to seal the patched area for at least this 30-day period. Sealing it may block it from the air and slow the curing process.