What is Mill and Overlay?

What is Mill and Overlay?

The modern world walks on pavement. Whether it’s roads, driveways, sidewalks, or parking lots – pavement makes up hundreds of thousands of acres across the country. Because our world is filled with pavement, there are several options for different budgets and benefits.

Paving can get expensive which means value is normally a top priority. If you’re considering different options for pavement and are on a budget, you should consider mill and overlay. To help you learn more about mill and overlay let’s detail what it is, why it’s beneficial, and good candidates for mill and overlay.

With the right conditions, a mill and overlay can give you a beautiful new driveway or parking lot at a fraction of the cost of removing and replacing.

More About Mill and Overlay

Mill and overlay is the paving process of removing the top few inches of an existing asphalt lot (milling) then putting on a fresh new coat of asphalt (overlay.) Mill and overlay is also known as mill and fill.

The Full Mill and Overlay Process

  • Inspection – Before you begin your asphalt will need to be inspected to determine if it’s a good candidate for mill and overlay. This means the base structure of your asphalt must be in good condition. If the inspection determines the base has been compromised, you may need to switch to remove and replace.
  • Site Preparation – Asphalt contractors prepare the site by removing any debris on the old asphalt. Contractors want a uniform surface for milling. During site preparation workers can adjust drainage and slope to fix previous problems.
  • Milling – The milling machine comes through to grind and remove the top layer of asphalt. Depending on the job this could be anywhere from a half inch to 6 inches of old asphalt. The base will be left intact.
  • Cleaning – Workers inspect the milled area for debris or abnormalities.
  • Tacking – Tack oil is applied to provide a “sticky” surface for the new asphalt.
  • Mixing – Hot mix asphalt is prepared for the overlay. The hot mix asphalt normally comes from the asphalt plant but can be mixed onsite.
  • Overlay – The hot mix asphalt is fed into the paving machine which evenly distributes new asphalt across the new surface.
  • Rolling – After the fresh asphalt is laid, paving contractors use heavy rollers to give the asphalt an even and uniform appearance.
  • Drying – Asphalt dries quickly. Your new mill and overlay should be ready for foot traffic in only a few hours and ready for vehicles within 24 hours. Your asphalt contractor can make approximate dry times depending on your job and current conditions.

Benefits of Mill and Overlay

  • Economical– Mill and overlay use much less material and labor than a full asphalt remove and replace so it’s naturally more cost effective. Asphalt isn’t very expensive but the less you use the more will stay in your wallet.
  • Easy – Removing and replacing an asphalt structure can take days or weeks but a mill and overlay is a much quicker process. Because they’re not removing and replacing the base layer the job goes much faster allowing you to open your lot or park back in your driveway sooner than later.
  • Looks Great – A fresh new coat of asphalt will look great on your property. You never see the base layer so neighbors will think you got a whole new sidewalk or driveway.
  • Strengthen – A new top layer of asphalt is more sound than crumbling and decaying asphalt. Old brittle asphalt can allow water to penetrate your base and cause structural issues but a fresh new layer every few years will keep your asphalt strong.
  • Better for Environment – The asphalt that’s milled from your driveway will be recycled into fresh asphalt for someone else. Your fresh layer will contain someone else’s old asphalt. Mill and overlay uses mostly recycled material and less greenhouse gasses than a remove and replace.

Who is a Mill and Overlay Good For?

A mill and overlay is appropriate when the base layer of the asphalt is structurally sound. Any large-scale cracking to the base or widespread damage throughout the asphalt is not good for a mill and overlay.

Mild to moderate damage like spiderweb cracks, staining, and pockmarks will not affect the quality of a mill and overlay. A certified asphalt contractor will need to approve your asphalt for mill and overlay.

Learning More About Mill and Overlay

Mil and overlay is a great option for those who want to save money and have a strong base on their current asphalt. If you think mill and overlay is right for you call the experts at Colorado Pavement Solutions today. We can inspect your asphalt, let you know if mill and overlay is a good option, then get you a free quote. Don’t wait for your asphalt to go downhill – contact CPS today.

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