Prepping your driveway – asphalt driveway sealer

March 26th, 2009 by Douglas

Putting down driveway sealer yourself can be a hard job, but if it is done properly it can give your driveway a beautiful finish that can last a few years. The most important key to the whole process is preparation. The highest quality driveway sealer in the world will simply not hold up on a dirty oil soaked driveway. So, here are a few things you need to do before you sealcoat your driveway.

  • Clean off the dirt and debris

 This is the most important part of the whole process. Driveway sealer doesn’t like to stick to dirt. There are a few ways you can do this. The easiest way for most homeowners is to wash down the driveway with your hose, using a spray nozzle if available. If you do wash it down, you need to let the driveway fully dry before sealing.

If there are any oil spots on the driveway, apply some dish washing liquid to the stain and let it soak for a few minutes. The soap attracts the oils from the pavement, which makes it easier to clean the spot.  Driveway sealer will not hold up properly on top of these oil spots, so make sure to treat them all this way.

Cracks should be broomed clean of dirt and rocks as well, expecially if you plan to apply a crack filler. An old kitchen broom will usually work fine for this duty. If you happen to have a leaf blower, it can be used to make the process easier. Simply aim into the crack and blow the debris out.

  • Fill the cracks

There are many products available for crack filling. The best product, by far, is going to be a hot applied crack filler much like:

 With the Pli- Stix you simply cut them to fit, and use a small propane torch to melt them into the crack. Hot applied crack filler, such as the Pli-Stix, hold up better through the freeze/thaw cycles than most cold applied sealers. This is a similar product to the crack fillers that are used on the highways and roadways, so you know it is made to last. The one downside to the Pli-Stix is that most driveway sealers will not overpower the color. With some people, this is not an issue, but if you want your whole driveway to look fairly seamless and cosmetic you need to look into a non-rubberised crack filler. I would rather bank on performance and invest into using the Pli-Stix. If you do not believe me, click the picture and read the reviews on yourself!

Other products for crack sealing are caulks or pourable crack fillers. A product like this is one of the easiest to use:

 Gardner Blacktop Driveway Crack Filler is a cold applied crack filler. It is a very popular product as it is very simple to use. Simply untwist the top, flip the spout around, twist the cap back on, cut off the tip, aim and squeeze.

Downsides to a cold applied crack filler is that they tend to not hold up well in the freeze/thaw cycle. In general you can expect no better than a couple of years out of them, and in many cases the cracks begin to reform after the first thaw. To some people this is an acceptable trade-off.

One last cold applied crackfiller is a trowel grade crack filler. Most home improvement stores will carry this, some even as little as 1 gallon.

It has the same benefits and drawbacks as the rubberised crack filler, with a couple of differences. It tends to blend better with the driveway sealer, to make the coat look more uniform. And it can also be mixed with portland cement to fill any low spots, or dips, in your driveway.  I will go over this second technique in a later article, it deserves its own space.

If you use a cold applied crack filler, I would invest in a U or V shaped squeegee.

These are the same tools the professionals use every day. They are a real back and knee saver. Simply put some crack filler on the crack, and use the squeegee to push the crack filler into the crack. You will notice that it will leave a thin layer on each side of the crack as you push, this is called a band-aid effect, and will give you a better overall bond to the pavement. And if you clean it off after use, it will be good to use next time.

  • Patch any holes

This step should also be taken before you seal your driveway. The driveway sealer will help hold the patch in place. Optimally you should cut out the bad spot and lay in the cold patch and tamp into place. But how many of us really own the tools to be able to do that?

As long as the spot is cleaned out, the best method is to use an asphalt primer first, which acts as a glue to hold the new patch in place. This primer (called SS, or SS 1-h) is usually not available to the public, and the smallest normal amount sold is 5 gallons (more than we need usually). The simple solution to this problem was listed above. A cold pour rubberised crack filler typically uses the asphalt primer as the bonding agent. Pour down enough to cover the spot completely, it doesn’t need to be too thick, but enough to hold down the patch. This will help the patch last much longer than simply putting the patch in without a primer.

 This is an example of a common cold asphalt patch. There are a few different types, but generally they all will do the job.

You will place the patch so that it sticks a little above the surrounding surface, then you need to pack the patch flush with the driveway. This can be done in a few ways. By hand with a tamp, or simply grab a board that is bigger than the hole, cover the patch and use your car to compact it. You can get away without the board, but it can end up leaving tire tracks, so I recommend you use the board.

It isn’t necessary to let it cure out like you would hot asphalt. Most contractors will apply the driveway sealer immediately after the patch is flush. If you do have a hot mix applied, you will need to wait 6 months to a year for it to properly cure.

And then you are done! Preparation is the most important step to properly apply your driveway sealer.

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