Raised only in winter
One area swells up during freezing weather, then drops closer to normal after several warm days.
Start here: Check drainage and where meltwater or downspout water is soaking the driveway edge.
Outdoor • Driveway
Driveway Frost Heave Bump
Direct answer: A driveway frost heave bump usually means water got under the surface, froze, and lifted one section higher than the rest. If the bump drops back down after a full thaw, the main problem is usually drainage and trapped moisture. If it stays high, cracks, or feels loose after thaw, the base under that section has likely shifted or broken down.
Most likely: The most common cause is poor drainage that lets water sit under one slab edge or one patch of asphalt, then freeze and push it upward.
Start by separating a temporary winter lift from permanent movement. That one distinction saves a lot of wasted patching. Reality check: a true frost-heave bump often improves in warm weather, but the water problem that caused it does not fix itself.
Don’t start with: Do not start by smearing crack filler or patch over the hump. That hides the symptom and usually breaks loose on the next freeze.
If the bump showed up during freezing weatherWait for a full thaw before deciding it needs patching or removal.
If the bump is still raised after thaw or is cracking apartTreat it as base movement or surface failure, not just a cosmetic ridge.
Last reviewed: 2026-04-05
What the bump looks and feels like
Raised and cracked after thaw
The hump stays high even after thaw, and you see fresh cracks, broken edges, or a hollow feel underfoot.
Start here: Look for failed base support or a section that now needs patching or replacement.
Concrete slab edge lifted
One concrete panel sits higher than the next, usually at a joint, creating a trip edge or tire thump.
Start here: Check whether water is entering the joint and freezing below that slab edge.
Asphalt hump with soft or broken top
The asphalt is crowned or buckled, sometimes with loose aggregate, splitting, or a soft spot nearby.
Start here: Check for trapped water and base failure before treating it like a simple surface patch.
Most likely causes
1. Water trapped under the driveway from poor drainage
Frost heave needs moisture. If roof runoff, yard slope, or low spots keep feeding water under the driveway, the same area lifts first.
Quick check: Look for downspouts dumping nearby, standing water after rain, or a driveway edge that stays wet longer than the rest.
2. Open joint or crack letting water into the base
On concrete especially, water gets through an open joint, freezes below the slab edge, and lifts that panel.
Quick check: Inspect the raised area for open seams, missing filler, or cracks that line up with the lifted section.
3. Base material that has shifted or broken down
If the bump remains after thaw or feels hollow, the stone base may have washed out, settled unevenly, or been pushed out of place over several seasons.
Quick check: After thaw, tap and walk the area. Hollow sound, rocking, or crumbling edges point to support loss below the surface.
4. Asphalt surface failure around a wet weak spot
Asphalt can hump where moisture repeatedly freezes below it, then crack and deform as traffic rolls over the lifted area.
Quick check: Look for nearby soft spots, alligator cracking, or raveling around the hump instead of one clean raised ridge.
Step-by-step fix
Step 1: Confirm whether the bump is seasonal or permanent
You do not want to repair a section that is still frozen and moving. A winter-only lift and a year-round hump get handled differently.
- Note whether the bump first appeared during a freeze or has been there through warm weather too.
- If the ground is still frozen, give the area time to fully thaw before measuring height or planning a patch.
- Mark the highest point with chalk and check it again after several warm days.
- Take a straight board or level and span across the bump to see how much it stands proud of the surrounding surface.
Next move: If the bump drops back close to level after thaw, focus on stopping water from getting under that area. If it stays raised, cracked, or loose after thaw, move on to checking for base failure and surface damage.
What to conclude: A temporary lift points to frost and moisture. A lasting hump points to structural movement in the driveway section itself.
Stop if:
- The raised area creates an immediate trip hazard or vehicle strike hazard that needs barricading now.
- The surface is actively breaking apart under foot or tire load.
Step 2: Check where the water is coming from
Frost heave is usually a water-management problem first. If you miss the water source, the bump often comes back after any surface repair.
- Walk the driveway during or right after rain if you can, and watch where water runs and where it sits.
- Check for downspouts, sump discharge, or landscape drains emptying near the raised section.
- Look along the driveway edge for low soil, eroded gaps, or places where runoff can slip under the slab or asphalt edge.
- Notice whether snow piles, plowed berms, or repeated meltwater collect in the same area each winter.
Next move: If you find obvious runoff feeding that spot, correct that drainage issue before spending time on patching. If no clear water source shows up, inspect the surface itself for open joints, cracks, and signs of support loss.
What to conclude: A repeat wetting source is the usual reason the same bump returns in the same place every winter.
Step 3: Separate concrete joint lift from asphalt base failure
Concrete and asphalt can both heave, but the repair path is different. Separate them early so you do not use the wrong fix.
- For concrete, inspect every joint around the lifted panel for open gaps, missing filler, spalled edges, and vertical offset between slabs.
- For asphalt, look for a broad hump, soft area, loose stone, alligator cracking, or a section that flexes slightly under weight.
- Tap concrete with a hammer handle or similar solid object and listen for a hollow sound near the raised edge.
- Walk the asphalt area on a mild day and feel whether the hump is firm or whether the top crust is breaking over a weak base.
Next move: If it is mainly an open concrete joint with a stable slab after thaw, the next move is keeping water out and monitoring for repeat lift. If the section is cracked, hollow, soft, or still displaced, plan for patching only if the damage is small and shallow. Larger movement needs section repair or replacement.
Step 4: Make the small repair only if the surface is stable
Minor patching works only when the driveway has stopped moving and the damaged area is limited. Patching over active movement is the common wrong move.
- For a small asphalt hump that has cracked or chipped after thaw but is otherwise firm, remove all loose material and patch only the broken top area with driveway patch material.
- For a small concrete spall or chipped edge left by the heave, clean out loose debris and use a concrete driveway patch material only after the slab has settled and feels solid.
- Do not fill a moving joint or bridge a live height difference with patch as a permanent fix.
- If the raised concrete joint is stable but open, keep water out with maintenance and monitor the height through the next freeze-thaw cycle rather than forcing a cosmetic fix now.
Next move: If the patch bonds well and the area stays level enough for normal use, keep watching through the next season and stay on top of drainage. If the patch cracks back out, the hump returns, or the area keeps moving, the base under that section is not sound enough for a surface-only repair.
Step 5: Decide between monitoring, drainage correction, or section replacement
By this point you should know whether you are dealing with a seasonal moisture problem, a minor surface repair, or a section that needs heavier work.
- If the bump dropped after thaw and the surface is still sound, correct runoff, keep joints and cracks from taking on water, and monitor next winter.
- If the area is small, stable, and only the top surface broke, finish the patch repair and recheck after rain and after the next freeze.
- If concrete remains lifted, offset, or hollow after thaw, get estimates for slab lifting, slab reset, or panel replacement depending on condition.
- If asphalt remains humped, soft, or broken after thaw, plan on cutting out and rebuilding that section rather than adding more filler on top.
- If the hump is tied to repeated runoff from nearby drainage, solve that water path at the same time or the repair will not last.
A good result: You end up fixing the actual cause instead of just hiding the bump for a few weeks.
If not: If you still cannot tell whether the section is stable, stop before buying more material and have a driveway contractor evaluate the base condition.
What to conclude: The lasting fix is matched to the condition: monitor a seasonal lift, patch a small stable defect, or rebuild a section with failed support.
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FAQ
Will a driveway frost heave bump go away on its own?
Sometimes, yes. If the lift is caused mainly by frozen moisture under the driveway, it may settle back down after a full thaw. If it stays raised, cracks, or feels loose afterward, the base or surface has likely been damaged and needs repair.
Should I patch a driveway bump in winter?
Usually no. If the ground below is still frozen, the driveway may still be moving. Wait for a full thaw unless you are only marking the hazard and doing temporary safety control.
Is a frost heave bump more common in concrete or asphalt?
Both can heave. Concrete often shows it as one slab edge lifting at a joint. Asphalt more often shows a broad hump, cracking, or a weak spot where moisture has been trapped below the surface.
Can I just fill the crack and ignore the bump?
Not if the area is still moving or staying raised. Filling the crack may slow water entry on a stable surface, but it will not fix a failed base or a slab that is still displaced.
When does a frost heave bump mean the driveway section should be replaced?
Replacement or section rebuild is usually the right call when the hump remains after thaw, the slab is offset or hollow, the asphalt is soft or broken, or patch repairs keep failing because the support underneath is no longer sound.