If you notice pools of water collecting on the surface of your asphalt driveway, your driveway may have developed surface deformations known as "birdbaths." These shallow pits get their names from the birds that often come to drink from the collected water, but while the birds may be a welcome sight, the birdbaths themselves certainly aren't.
While birdbaths in your gravel driveway may not look as serious as potholes or severe cracks, they can cause just as much damage over time if they are not repaired as soon as possible.
What Causes Birdbaths In Asphalt Driveways?
Birdbaths can form in asphalt driveway for a number of reasons:
Improper Construction
If the hot or cold asphalt mix used to create your driveway was not mixed thoroughly before laying, it may contain pockets of unmixed material and/or water. These pockets are much weaker than properly mixed asphalt, and are likely to collapse and create birdbaths soon after the driveway is laid.
Shifting Soil
If the soil underneath your driveway shifts, parts of your driveway can lose their structural support, causing them to collapse. Significant soil movement can create potholes, sinkholes and cracks, but slight movements are more likely to create shallow birdbaths.
Soil shifting can occur due to ground tremors or subterranean construction work (such as laying new sewer lines). Soils containing large quantities of absorbent clay are especially vulnerable to shifting, as these clay molecules expand rapidly when exposed to moisture.
Poor Driveway Drainage
If rainwater drains away from your asphalt towards a small, specific area, the collecting rainwater can cause the ground beneath the driveway to erode close to the drainage area. This erosion can cause birdbaths, and may lead to more serious damage if the drainage problem is not corrected. Installing French drains is a cheap and easy way to avoid localized drainage problems.
How Are Asphalt Driveway Birdbaths Repaired?
It is always important to repair driveway birdbaths sooner rather than later. If standing water is allowed to sit in the birdbath(s) for long periods, it will start to dissolve the binders keeping the top layer of asphalt together, leaving it permanently weakened and vulnerable to further damage. Standing water can also soak into the aggregates beneath the top asphalt layer, causing even more structural damage.
It may be possible to repair a shallow, isolated birdbath yourself. They can be filled in using a mixture of crushed rock and asphalt emulsion, or patched over using cold patch asphalt. Once dried and set, the repairs will need to be sealed with asphalt sealcoating. These supplies can be found at most home supply stores.
However, these are temporary fixes at best, and will not be as strong and tough as professionally repaired asphalt. DIY repairs may not be practical if you park heavy cars or trucks on your driveway, and cannot be used to effectively repair deeper birdbaths. DIY repairs are also unsuitable for repairing multiple birdbaths, as multiple birdbaths are usually caused by more severe issues with the driveway's aggregate layer.
Calling in a professional asphalt driveway repair service is always the safest and easiest option, and will restore your birdbath-damaged driveways to its original strength and stability. Professional services use hot-mix asphalt and other commercial-grade repair materials, and will be able to fill in and repair the deepest birdbaths as quickly as possible.
Professional repair services will also be able to determine why your driveway has developed birdbaths in the first place, and help you avoid future problems. For example, if aggregate erosion is causing birdbaths to appear, professional services can access and replace the damaged aggregate to prevent further damage.
Contact an asphalt driveway repair service to learn more.
Share10 February 2023
Paving contractors spend all day laying the pavement. We figured that the least we could do was write about it! In other words, we plan on laying the pavement of information. Yes, that sounds a little cheesy, but sometimes it's okay to sound cheesy when talking about something as serious as pavement. We caught your attention, didn't we? Now that we've caught your attention, allow us to share a little more about this blog. It will feature articles about paving and pavement contractors, and we plan on providing a lot of different information and perspectives as we go. You're welcome to join us!