In the United States, asphalt paving is an important component of the construction and repairs of driveways, roads, and parking lots. Though this might be an simple process, timing and weather conditions contribute significantly to having a long lasting and quality pavement. One of the most popular questions posed by both homeowners and contractors is: Can asphalt paving be carried out when it’s raining?
The answer to this no, you put down asphalt paving when there is rain. Below, we are going to look at why, what the risks are, and what to do in case you are experiencing a wet forecast.
The Importance of Weather to Asphalt Paving
The Effect of Temperature and Moisture
The laying and compaction of asphalt paving is dependent on the prudent use of hot mix asphalt that is required to be at a particular temperature during the process.
Asphalt Paving Will Only Take Place at Its Best Under the Following Circumstances:
- Dry weather
- Air temperatures higher than 50 degrees F (10 degrees C)
- Warm surface temperatures
Incorporation of rain into the equation may have a drastic effect on all the above.
Why You Shouldn’t Pave Asphalt in the Rain
Moisture Weakens Asphalt Binding
Asphalt is prepared by combining the aggregate (gravel, sand, and crushed stone) with a petroleum-based binder. A clean dry area must be selected to put this binder.
Rainwater Disrupts the Bonding Process When It is in the Mix and It May Result in:
- Poor compaction
- Separation of materials
- Reduced structural integrity
Steam and Cracks Can Form
When in contact with rain or surface water at temperatures of approximately 275⸰F to 325⸰F, asphalt produces steam. This sharp change of temperature may crack the asphalt or create small holes (so-called “popcorn effects”) within a minute or so.
Dangerous and Slippery Working Conditions
When raining, paving crews are working under unsafe conditions. The equipment is prone to slipping, the visibility of the operators might suffer, and the wet surface can lead to the inability to maintain the correct paving depth or smoothness.
Reduced Pavement Life expectancy
Pavement over a wet surface normally causes premature pavement failures.
You Might Notice:
- Breaking and holes in a few months
- Water that leaks through the asphalt and is weakening the foundation
- High maintenance rates
What If Rain Begins During the Paving Process?
If rainfall begins after the paving has commenced, then the paving crew should make a quick analysis.
In General:
- Light sprinkles are enough to prevent the continuance of paving, but if there is some heat and dryness on the surface, it can be laid a little longer
- When it starts raining steadily, then work must be terminated at once
- Any part that is not completed should be covered with tarps to ensure that it is not penetrated by water
- Wet areas must be left to dry fully, only then should paving resume
Can You Sealcoat Asphalt in the Rain?
Sealcoating is a protective surface that is put on the asphalt surface; it is even more sensitive to moisture than paving.
The Application of Sealcoat During Rain or a Wet Surface Will Result In:
- Improper curing
- Streaks or peeling
- Shortened sealcoat life
The sealcoating should not be done in rain within a period of 24 hours.
How to Prepare for Weather When Scheduling Asphalt Work
Check the Weather Forecast
Follow up on weather forecasts in the area where you are planning to carry out the paving. Most contractors will delay the project when it is likely to rain within a period of 24 to 48 hours.
Plan for Dry Seasons
For most regions of the U.S., the optimum time of the year when asphalt paving can be done is during late spring, summer, or early fall when it is warm and with less rain.
Talk to Your Contractor
Professional paving companies know the dangers of paving during the rain and will tend to reschedule if the weather looks unfavorable. They will want to ensure your investment.
Are There Any Exceptions?
Exceptions are extremely few. Certain cold mix asphalts (which are only used temporarily as emergency patches) can be installed under less-than-perfect conditions, such as light rain. However:
- These are not the long-term solutions
- Cold mix asphalt is applicable primarily in a temporary repair
- It is still going to require the surface to be paved accordingly
What if We Wish to Pave in the Rain Anyway?
Should you or your contractor choose to proceed regardless of wet weather, you may experience:
- Delamination: Asphalt layers which peel off
- Rutting: grooves developed as a result of poor compaction
- Water Intrusion: Causing freeze-thaw cycles and pre-mature damage
- Legal and Warranty Concerns: There are a number of reputable paving firms who will cancel the warranty whenever a job is performed during bad weather
Finally, an attempt to pave in the rain to save time is normally associated with increased repair and replacement costs in the future.
Alternatives: What Can Be Done Instead?
The following are some productive alternatives:
- Site Preparation: Final grading, base compaction, and drainage work can be completed as soon as the surface is dry.
- Enhance Drainage: Water runoff should be taken care of to facilitate future paving.
- Temporary Patching: In case of potholes or damage requiring urgent service, then cold mix asphalt may be a useful remedy.