«leftbraned

Back in September 2004, I had a tar and chip (bituminous surface treatment) driveway installed in place of the existing gravel drive that came with our old house. Because there wasn’t (and still isn’t) much web information on tar and chip driveways, I thought I’d briefly summarize my experience.

We called the original contractor (Craig Hup) in, to take a look and let us know our options. Unfortunately, he said that it’s not really possible to patch the driveway; he would have to redo the entire job [but see readers’ comments below for discussion on whether this is actually true]. And, at current oil prices, the cost of the job would be something like $2/square foot–about double what we paid three years ago.

Some context:

The washout was caused by a flash rainstorm.

The lawn next to the driveway (in the spot near the washout) slopes back towards the driveway–which means that water may not have enough room to run off the driveway, especially during an unusually heavy rain.

After talking with some neighbors (and a couple of other local contractors), it’s apparent that we’re not alone. The recent rainstorm caused damage (potholes or washouts) to several local driveways: gravel, tar & chip, and asphalt alike.

We’re still deciding how to handle it.

What Does Tar & Chip Look Like?

(Photos: tar and chip driveway, completed; installation. More photos coming soon.)

If you’re a city boy, like me, you probably have no clue what a tar and chip road looks like. Well, our driveway looks more or less like a normal gravel drive, except that, in most spots, if you tried to sweep away the gravel, you’d reach a grey, pseudo-solid, conglomerated rock base. (If it were true gravel, you’d hit earth.)

We put slightly too much stone on the drive after it was tarred, so there’s more gravel than we’d ideally like (making look very much like a regular gravel drive). Some people might prefer the way that looks, though.

We also chose to go with grey stone, for a few reasons. For one, it fit better with our house (even though, in a vacuum, I might prefer red stone). More importantly, it was easier (cheaper) to get, and will make future maintenance much less of a headache. Grey is easy to match; I know I’ll be able to re-chip the driveway easily later on. Also, it’s not easy to find a contractor who does tar and chip (see below), so the fewer exceptions to their normal practices (e.g., grey stone), the better.

Why Is It Better?

Advantages of tar and chip over blacktop (asphalt):

• Maintenance. Asphalt requires periodic sealing and repairs; tar and chip is relatively maintenance free–no sealing, and fewer repairs. We have no visible cracks (perhaps the gravel layer hides them?), save for one spot where the substrate wasn’t laid correctly.
• Traction. In wet or snowy weather, the rough surface provides extra grip to foot or tire.
• Cost. Tar and chip costs less to install than asphalt. (In my case, it was half the cost.) I think it cost us just under $1 per square foot.
• Durability. My driveway will last longer than an “equivalent” blacktop drive.

Disadvantages:

• Finding a contractor. The number one problem with tar and chip driveways is: hardly any paving contractors still install them. (See below for reasons.) You may (you will!) have trouble finding someone who even knows what tar & chip is, let alone can install it. I got lucky–and I’ve included my contractor’s contact information below, in case you’re local (NJ).
• Winter shoveling. As with a gravel drive, you’ll find winter snow plowing and shoveling to be harder than with blacktop. But, we have had our driveway plowed several times, and also have shoveled several feet of snow over the past two years, and have had no issues with our tar & chip drive. The worst consequence has been stray gravel getting on the lawn. (But certainly no worse than with the old, pure gravel drive.)
• Weeds. A handful of weeds do manage to come up through our tar and chip driveway, here and there. I’m not sure if it’s because the tar didn’t fully coat some areas during our installation, or whether it’s an inherent property of tar and chip roads… but in any case, it’s not too bad.
• Installation time frame. Installation of a tar & chip driveway requires warmer temperatures than does blacktop, so the “season” of favorable weather is shorter. Where I live, blacktop can be installed through October, but tar and chip can’t be done that late.

Why Doesn’t Everyone…?

So, if tar and chip is so much better than common asphalt, then why doesn’t everyone use it?

Well, you might also ask why we plant non-native grass species in lawns, when they require an unnatural regimen of extreme watering, fertilizing and weed killing.

Or why you can’t get a decent tomato in a supermarket.

Or why coca-cola is a corn product.

The short answer is: corporate profits have driven these trends. (The details on lawns, tomatoes and Coke are not really on-topic here, so I’ll leave it at that.)

Using tar as a binder requires warm-ish temperatures (for the tar to remain tacky). This limits the paving season during which (tar and chip) roads can be laid. Concrete/asphalt manufacturers realized, several decades ago, that by mixing road materials in their plants–rather than on-site–they could extend the paving season, since they could control the temperature within the plant. Today, that’s what they do–mix asphalt in a plant and transport it to the road site.

Which is all fine and dandy–except if you want a product that’s better for you (tar & chip, native grasses, sugar…), instead of better for them (asphalt, Kentucky Bluegrass, corn syrup…).

Contact Information for our Contractor

Our paving contractor was Craig Hup, of Hup & Sons. We’re very satisfied with the job he did on our driveway, so we recommend considering him if you’re planning a tar and chip project. Note that they did not offer an official warranty on the work–which I found odd, since tar and chip should outlast a blacktop drive–but I chalk that up to their perception that it was risky, due to lack of data (i.e., too few installations to know how it would hold up).

You can reach Craig at (908) 832-7878. (And please mention to him that you read my article. :) )

For More Information

• Wikipedia
• Ms. Builder [dead link]
• Ask the Builder
• Ask the Builder (Reprise)
• Gardenweb