What It Is
Tack coat is a thin application of asphalt emulsion sprayed onto an existing pavement, milled surface, or intermediate lift before new hot-mix asphalt is placed on top. Its job is to bond the new layer to the old.
Why It Matters
Without a proper tack coat, the new asphalt lift can slide, delaminate, and reflect cracks from below. With a proper tack coat, the two layers behave as a bonded pavement structure.
Tack coat is one of the small details that separates a durable overlay from one that peels apart in a few years.
Application Best Practices
- Sprayed at manufacturer coverage rate — typically 0.05 to 0.10 gallons per square yard residual
- Emulsion must break (turn from brown to black) before paving over it
- No traffic on tack-coated surfaces before paving
- Trackless tack materials are available for zero-track applications
Common Failures
- Tack skipped entirely
- Rate too low to bond
- Rate too high, causing bleeding through the new lift
- Paving before the emulsion has broken
Verification
Owners can watch for tack application during paving day. A visible black or dark brown film across the entire surface before the paver rolls is what to look for. A dry, unaddressed surface is a red flag.
Related Services
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Get a Free Estimate
Quality Paving provides estimates throughout Middle Georgia and surrounding communities, subject to project location and scheduling. If you would like an honest assessment of your property, request a free estimate or call (770) 946-5355.
Frequently Asked Questions
Is tack coat always necessary?
On any overlay or milled surface, yes. On a bonded lift-on-lift paving operation with proper timing, it may be optional per spec.
Does tack coat cost extra?
It is normally included in the paving line item. If it is a separate charge, ask why.
What is a trackless tack?
A polymer-modified emulsion that dries to a non-tracking state. Useful where vehicle or foot traffic must cross before paving.