Why Driveway Exposed Aggregate Sealing Matters
Exposed aggregate is prized for its rugged beauty and slip-resistant surface, but the same textured finish that adds curb appeal also creates thousands of tiny “pores.” Left unprotected, those pores soak up water, de-icing salts and UV rays, leading to fading, pop-outs and expensive repairs. Driveway exposed aggregate sealing is the low-cost insurance policy that locks in colour, blocks contaminants and keeps the stones firmly bonded for 5–7 years at a time.
In this guide you’ll learn when to seal, which products work, how pros quote the job, and the exact steps you can DIY—or supervise—so the finish looks wet (not greasy) and lasts season after season.
Top 5 Benefits of Sealing Exposed Aggregate
- Colour revival: A quality seater deepens the tonal contrast between stones and cement paste, giving the “just-poured” look.
- Freeze-thaw protection: By keeping water out, you cut spalling and cracking by up to 80 % in cold climates.
- Oil & stain guard: Spills bead up instead of soaking in, so cleanup is a 30-second wipe, not a permanent eyesore.
- Dust suppression: Sealed surfaces shed the chalky “dusting” that otherwise tracks into the house and garage.
- Increased resale value: A well-maintained, glossy driveway photographs better and signals “attention to detail” to buyers.
When to Seal (and Re-seal) Your Driveway
First-Time Cure Window
New exposed aggregate must cure a minimum of 28 days before any sealer is applied. Premature sealing traps moisture, causing clouding or white haze that can’t be reversed without stripping.
Re-Sealing Schedule
- Sunny, high-UV regions: every 3 years
- Snow-belt with salt exposure: every 2–3 years
- Shaded, mild climates: 4–5 years
Quick Test for Absorption
Sprinkle a few tablespoons of water on the surface. If it’s not absorbed within 60 seconds, the existing sealer is still working; wait another season.
Choosing the Right Sealer
1. Penetrating Silane-Siloxane (Natural Look)
Best for homeowners who want zero gloss and maximum breathability. It lines the pores without forming a film, so freeze-thaw cycles can’t pop the surface.
2. Water-Based Acrylic (Low-Sheen to Satin)
Easy soap-and-water cleanup, low odour and good UV stability. Ideal for first-time DIYers.
3. Solvent-Based Acrylic (High-Gloss “Wet Look”)
Delivers the richest colour enhancement but contains higher VOCs; check local regulations. Must be back-rolled to avoid roller marks.
Additives to Request
- Non-yellowing UV inhibitors
- Slip-resistant micro-aggregate for sloped driveways
- Mold-stat packets for shaded, tree-lined properties
Preparation Checklist: 80 % of Success Happens Before the First Drop
- Power-wash: 3,000 psi, 25° green tip held 12 in. from surface. Remove all tire dressing overspray, leaf stains and fertilizer rust.
- Spot-clean oil: Use a degreaser with a micro-emulsifying agent; rinse until water sheets evenly (no beading).
- Re-patch exposed pop-outs: Fill with polymer-modified cementitious repair mortar; let cure 24 h.
- Etch if needed: If the surface feels slick or was previously sealed with an incompatible product, apply a citric-acid etch, scrub, then neutralize.
- Mask & protect: Run 12-inch contractor paper along garage doors, sidewalks and landscaping; secure with low-tack blue tape.
- Moisture check: Tape a 2 × 2 ft plastic sheet for 24 h; if condensation forms, wait another dry day.
Step-by-Step Application Guide
Tools You’ll Need
- 18 in. ⅜-nap phenolic roller frame
- Solvent-resistant pump sprayer (for acrylics) or garden sprayer (for water-based)
- Seamless microfiber roller covers
- Brush for cutting-in edges
- Spiked shoes to walk on freshly sealed surface
- Leaf blower for final dust removal
Ideal Weather Window
50–85 °F, humidity below 70 %, no rain for 24 h, surface temperature at least 5 °F above dew point.
Two-Coat “Wet-on-Wet” Method
- Start at the garage and work downhill; maintain a wet edge.
- Spray a light tack coat (~75 sq ft per gallon) to promote adhesion.
- Back-roll within 60 seconds to even out the film and knock down bubbles.
- Apply second coat perpendicular to the first while still tacky (usually 30–60 min).
- Broadcast anti-slip grit into the second coat if required.
- Block foot traffic 4 h, vehicle traffic 24 h (48 h for heavier trucks).
Cost Breakdown: DIY vs. Pro
DIY Budget (1,000 sq ft driveway)
- 5 gal premium water-based acrylic sealer: $250–$300
- Prep chemicals & rental: $75
- Tools (if buying): $90
- Total: ~$420
Professional Quote Range
$1.10–$1.75 per sq ft for two coats, including prep and a 3-year warranty. Complex layouts, oil remediation or steep grades can push the price to $2.00 per sq ft.
Rule of thumb: If your driveway is larger than 1,500 sq ft, hiring a licensed applicator often costs only 25 % more than DIY once you factor in your time and disposal fees.
Common Sealing Mistakes Homeowners Make
- Over-application: Thick films turn white and peel. Stick to the coverage rate printed on the pail.
- Sealing over damp concrete: Moisture trapped under the film causes “frosting” that requires chemical stripping.
- Skipping the second coat: One coat wears through in high-traffic tire paths within a year.
- Using interior sealer outside: Interior products lack UV blockers and yellow within months.
- Ignoring forecast humidity spikes: A surprise overnight dew can ruin gloss and create blotches.
Year-Round Maintenance Tips
Spring
Sweep away winter sand, rinse with a garden hose and inspect for hairline cracks. Touch-up small areas with the leftover sealer you saved in an airtight jar.
Summer
Wash tire marks with a pH-neutral car-wash soap; avoid harsh degreasers that can dull the finish.
Fall
Blow off leaves daily—tannins from maple and oak can tattoo unsealed margins in under 48 hours.
Winter
Use calcium magnesium acetate (CMA) instead of rock salt; it’s 70 % less corrosive and won’t whiten the sealer.
Eco-Friendly & Local Regulations
Many counties now restrict VOCs to 100 g/L. Ask your supplier for “Driveway Exposed Aggregate Sealing” products that carry the GreenSeal GS-11 stamp. Water-based formulas clean up with tap water—no mineral-spirits disposal headaches—and are safer for pets that walk across the driveway.
Frequently Asked Questions
Foot traffic is okay after 4 hours, but wait a full 24 hours for cars and 48 hours for heavier trucks or RVs. Cool, humid weather can double those times—always do the “thumb test”: press the edge; if no imprint remains, you’re clear.
Yes, but you must strip or aggressively etch the old glossy film so the new matte product can bond. A light grind with a 100-grit diamond pad on a floor buffer usually does the trick; rinse and let dry 24 h before the new application.
Blotchiness indicates either under-application in those spots or trapped moisture. Wait for a dry day, scrub the area with a neutral cleaner, rinse, then apply a thin refresher coat only to the affected panels. Future coats should be sprayed and back-rolled for even coverage.
While you won’t battle freeze-thaw, UV rays still fade stone colour and the cement matrix can dust. A breathable penetrating sealer every 4–5 years keeps the surface looking new and reduces staining from lawn chemicals or vehicle leaks.