I've rebuilt more driveways than I've built from scratch. That's not a coincidence — it's the predictable result of a lot of residential driveways going in cheap, skipping the parts that don't show, and then failing inside three or four NH winters. The homeowner calls me to “top it up,” I walk it, and we end up having the longer conversation: the base is dead, the crown is gone, the culvert is crushed, and adding another three inches of 3/4 over the top is going to wash away by June.
Doing a driveway right isn't expensive in the grand scheme, but it's not cheap either. The thing that makes the difference between a 20-year driveway and a 3-year driveway is almost entirely underground. If you're about to put a new driveway in — or you're wondering why yours is falling apart — this is the real guide. NH-specific, real numbers, no magic.
Site assessment — what I look at first
Before I quote anything, I walk the run and read it. A good driveway is a response to the site, not a cookie-cutter strip of gravel. Here's what I'm looking at:
- Grade. How much does the land rise or fall from the road to the parking area? Steep grades (over 10-12%) are their own problem — they're hell in winter and they wash hard in spring.
- Drainage direction. Where does water currently go when it rains? Where do I want it to go? Does the driveway cross a natural drainage path?
- Soil type. Sandy loam drains well and builds fast. Heavy clay is a nightmare — holds water, heaves in winter, and will swallow an under-built base. Silt is somewhere in between.
- Access and turning radius. Where does the driveway meet the road? What's the sight line? Is there enough room for a pickup with a trailer to swing around without going in the lawn?
- Length. 60 feet and 600 feet are wildly different projects. Length also dictates how many drainage features you need.
- Existing utilities. Buried propane, septic lines, electric. All of that needs to be marked and respected before anyone turns soil.
- Frost-prone low spots. Areas that hold water and freeze will heave every March no matter what you put on top — so those spots need the base addressed first, not the top.
Base prep — the part nobody sees
Here's the single biggest difference between a 20-year driveway and a 3-year driveway. A proper base is three distinct layers totaling roughly 12-18 inches of stone, built on compacted subgrade with geotextile fabric on the bottom where soil is marginal. Most cheap driveways skip to the top layer and lay it right on native soil. Then they fail, predictably.
My real NH base build, from the bottom up:
- Strip topsoil and organic matter. Anything that rots is out — topsoil, root mats, wet clay pockets. Depending on the site, this is 6-12 inches of removal. Leaving organics under a driveway guarantees settlement.
- Compact the subgrade. The exposed native soil gets compacted with a roller or a heavy excavator tracking it in. If it pumps water up when you walk on it, you've got more work to do — that spot needs drainage or additional excavation before stone goes on.
- Geotextile fabric where the soil is marginal. In a lot of Hill, Bristol, and Franklin sites with silty or clayey soil, I'll roll out nonwoven separation fabric before stone. Keeps soil from pumping up into the base over years and extends the life of the driveway significantly.
- 6-10 inches of 3-4 inch crushed stone base. Big angular rock. This is the structural layer. It locks together, bridges soft spots, and doesn't settle. Deeper on soft or wet sites, shallower on good firm ground.
- 4-6 inches of 1.5-inch crushed. Middle layer. Binds the base together, fills the voids between the big stuff.
- 2-3 inches of 3/4-inch crushed as the wearing surface. This is what you see. Small enough to ride smooth, big enough to stay locked under traffic.
Each layer gets compacted before the next one goes on. A driveway laid all at once without step compaction has soft layers inside it that show up as sinking within a year or two.
“A driveway built without proper base doesn't fail slowly. It fails on a predictable 2-to-4-winter timeline, and adding more gravel on top doesn't fix it.”
Drainage — crown, swales, culverts
This is where more driveways fail than anywhere else. Water kills driveways. A driveway with good base but bad drainage still washes out. A driveway with modest base but excellent drainage often survives.
Crown is the slight arch across the driveway's width — higher in the middle, lower at each edge. You want 2-3% slope from centerline to edge. On a 12-foot-wide driveway, that's 3-4 inches of rise in the middle. Without a crown, water runs down the length of the driveway instead of sheeting off the sides, and it digs a channel straight down the middle. You'll see this as a valley running the whole length, with pooled puddles in the low spots.
Swales are shallow ditches along each side of the driveway, usually 12-18 inches deep and a foot or two wide, graded to carry runoff away. They catch the water that sheets off the crown and send it somewhere useful — into a drainage area, a dry well, a culvert, or back to native ground beyond the traveled surface. Without swales, water sits next to the driveway and saturates the subgrade, which accelerates frost heave and softens the base.
Culverts are pipes that carry water under the driveway when the driveway crosses a drainage path. 12-inch diameter is the absolute minimum for residential use. 15-inch or 18-inch is more appropriate for anything with real seasonal flow, especially in spring mud season when the Pemigewasset watershed is moving serious water. An undersized or crushed culvert is the single most common reason driveways fail during spring thaw — water backs up behind it and takes the whole section out.
What it costs in the Lakes Region
Real 2026 numbers for gravel driveways built to last:
- Short new residential (60 feet, flat, good soil, no culverts): $3,500 to $5,500 done right. Includes topsoil strip, compacted base, three layers of stone, crown, and basic edge grading. This is a suburban lot or a short camp driveway.
- Medium new (120 feet with one culvert crossing): $6,500 to $11,000. Typical Lakes Region residential job. Factors that move the number: driveway width (10 feet vs 14 feet), culvert size, whether the site needs fabric, and access for my equipment.
- Long or uphill rural (300 feet, grade management, proper drainage, 2 culverts): $14,000 to $22,000. These are camp roads, lake-access driveways, or rural lots with real distance. The cost climbs with grade — a steep uphill run requires more base stone to prevent washout, deeper swales, and sometimes waterbars across the surface to break the flow.
What moves these numbers up or down fastest: length (linear), base depth (driven by soil quality), ledge (expensive to remove), culvert count and size, and access for my equipment. A driveway I can run down with a dump truck direct costs less than one I have to wheelbarrow stone into. If you're getting quotes, a bid that's 40% cheaper than everyone else is almost always skipping base depth or drainage — ask specifically about both. You can read more about my excavation and site work, along with materials delivery and drainage, on the main site.
NH-specific issues
A few things we deal with here that generic national guides don't cover.
Frost heave. The NH frost line runs about 4 feet deep. If water is trapped in the subgrade under a driveway, it freezes, expands, and pushes the surface up — often unevenly, creating washboards and bumps. Proper drainage is the cure: if water can't sit in the base, it can't freeze and heave the driveway.
Mud season. April and early May are the worst time to drive on a gravel driveway, and they're the worst time to have one installed. The ground is saturated, subgrade is soft, and anything you do on top sinks in. I generally won't install a new driveway between mid-March and early May unless the site is unusually well-drained. Fall installs — September and October — give you a full winter of settling before spring stresses it. I wrote about that timing here.
Ledge. Granite bedrock sits anywhere from 1 foot to 20 feet down across the region. If a driveway route crosses a ledge ridge, you've got three options: route around it (cheapest), cover it with enough base stone to make a smooth surface (works if it's low), or break through with a rock hammer (expensive, adds $1,000-$5,000 depending on volume). I always probe for ledge on long driveway runs before quoting.
Steep grades. Anything over 10-12% grade starts getting into winter-driving-nightmare territory. If the site forces a steep driveway, it needs extra drainage, possibly a textured surface (larger surface stone), and ideally a flat landing section at the top and bottom. In the worst cases, the only answer is a switchback to break the grade.
Maintenance — what a good driveway needs
Even a great driveway needs care. Here's the real maintenance rhythm:
- Annual top-up: 1-2 cubic yards of 3/4 crushed spread in the spring, raked into low spots, keeps the wearing surface alive. Cheap insurance.
- Spring regrade: After mud season, a pass with a box blade or grader to re-establish the crown and smooth out washboarding. Can usually be done with a small tractor attachment.
- Culvert clean-out: Twice a year — before winter and after mud season. Clear leaves, sticks, and sediment so the pipe flows freely. A clogged culvert is the leading cause of spring washout.
- Keep the crown alive. Over the years, traffic and weather flatten the crown. When you can see standing water sitting on the surface after rain, it's time to regrade.
- Every 10-15 years: A larger rebuild — adding material, re-grading the whole run, replacing worn culverts, potentially re-doing sections where the base has failed.
Signs you need a rebuild, not a top-up
Homeowners often come to me asking to “add some gravel.” Sometimes that's the right answer. Sometimes it's throwing good money after bad. Here's how to tell the difference:
- Washboarding that won't flatten even with fresh material on top — the subgrade is moving. Rebuild territory.
- Potholes that return within months of being filled — water is getting under the surface and pumping material out with every vehicle pass. Drainage and base issue.
- Standing water on the surface hours after rain — crown is gone, or drainage failed. Regrade at minimum.
- Crown reversed (water running toward the house) — I see this a lot where driveways have been “topped up” without respecting the slope. Water now flows toward the foundation. Needs to be regraded.
- Sinking spots that keep coming back — organic matter under the driveway, or a collapsed culvert, or a spring underneath. Rebuild the affected section.
If two or more of those are true, adding gravel on top is a waste. The driveway needs the base worked on. That's a harder conversation but a much better use of the money — a rebuilt section lasts, a topped section just defers the real fix for another six months.
What I do on a site visit
Driveway quotes are very site-specific — more than most services. I'll walk the whole run, read the grade, probe the soil, check for ledge and utilities, look at existing drainage (if there's a driveway already), and write you a real flat-rate bid that specifies the base depth, the culvert sizing, and the final stone layers. No pressure, no charge for the visit. If your existing driveway just needs a top and regrade, I'll tell you that honestly too.