The door under your kitchen sink is lifting along its bottom edge, and you can catch the finish with a fingernail. Or a drawer front beside the dishwasher has a sheet of surface curling off one corner. It reads as a paint problem, and it usually is not — the finish is the part you can see letting go of something underneath that decided first.
Three things cause this in a kitchen, and from across the room they look identical. Up close they do not. The difference is readable standing there with a flashlight: where the failure started, which way it is traveling, and whether the material under the break is still hard when you press it.
Read where it started, not where it is worst
By the time anyone calls us the peeling has spread and the original break is buried inside the damage. Find the edge of the sound finish and work backwards to the smallest, oldest failure you can see. That spot is the diagnosis. The rest is what happened after.
- It starts at a bottom edge or a bottom rail and climbs. Water. The failure came up from the edge of the panel, not down from the face.
- It starts at a corner and peels inward as one continuous skin. Heat. A wrapped surface is releasing from what it was wrapped around.
- It starts wherever hands land — around the pull, along the top edge of a drawer front, on the stile you push past. Bond. The coating never gripped, and daily contact is only what finally proved it.
Then press the exposed material at the break with a thumbnail. Hard means the substrate is fine and only the coating failed. Soft, spongy, or gritty like damp cardboard means the panel itself is gone, and no finish work brings that back.
Cause one: water standing on an unsealed edge
The sink base is the wettest cabinet in the house and almost nobody treats it that way. Hands drip on the way to the towel. A dishcloth hangs over the door all afternoon. A supply stop weeps behind the bin. All of it runs down the door face and stops at the bottom rail, or pools on the cabinet floor against the back of the toe kick where nothing dries.
Every one of those surfaces is a cut edge. The face of a cabinet panel is sealed by its finish. The edges — machined for a hinge bore, a drain hole, a pair of stops — frequently are not, and an unsealed edge is an open straw.
How you tell
- The lift runs along the bottom of the door in a band, worse at the two bottom corners than in the middle.
- That edge feels thicker than the rest of the door. Run a finger down it and compare it to the top rail — swelling is a bulge you feel before you see it.
- The finish is not chipping. It is lifting in a lip, still attached higher up and pushed away from below.
- The bottom edge is darker than the face, and drying it does not lay the lip back down.
That is a core that took on water, swelled, and shoved the coating off from underneath. Particleboard does it first and worst: the chips swell, the resin bond releases, and it does not dry back to flat. MDF drinks a raw edge just as fast and is worse at giving it up. Plywood swells and mostly recovers, which is why the same slow weep leaves a stain in one kitchen and a ruined door in another — the whole of what a cabinet box is made of.
What the repair actually is
If the panel under the break is still hard, the door comes off, gets sanded back past the lift, sealed on that edge, primed and refinished. It holds, as long as the water stops.
If the core is soft, the door is finished. You cannot dry a swollen chip core flat again, and filler only hides the shape for a season before the same edge opens further up. That means a new door — and if several fronts in the run are in the same state, it is really the repaint, reface or replace question rather than a patch.
Cause two: heat and steam from the dishwasher
This one is geographic. It happens to the doors flanking the dishwasher and nowhere else, because that is where a machine vents hot moist air at the end of its cycle — some out the top of its own door, some out a side port, straight at the cabinet next to it.
How you tell
- The damage is confined to the fronts either side of the appliance. Walk the rest of the run and it is perfect.
- It releases as a continuous sheet from a corner, not in chips, and the sheet wants to curl.
- Under it the substrate is smooth, tan and hard. No swelling, no dark staining.
- Sometimes it is not a face at all but a strip of edge banding that has come off whole, still holding its shape.
That is a thermofoil door, or a banded one. Thermofoil is a vinyl skin heat-wrapped over MDF, and the adhesive holding it was beaten by the same thing that applied it. Once a corner releases, the bond is broken across an area whose boundary you cannot see.
Why this one does not get repaired
Contact adhesive under the lifted corner holds until the next hot cycle, and then you are back where you started with a wrinkle in the skin. Painting over it is worse: a bonding primer sticks to thermofoil perfectly well, and the thermofoil keeps letting go underneath, taking the new finish with it. That is the argument in what a factory finish actually takes — a good coating on a substrate that is already moving is money spent on a delay.
The honest answer with thermofoil is new doors on the existing boxes, with the boxes sprayed to match. Check where the machine is actually venting while you are in there — clearance and vent path are part of fitting a dishwasher, and an appliance that has cooked one cabinet will do the same to the next door.
Cause three: a finish that never bonded
If the kitchen has been repainted at some point, check this one first. The giveaway is that the damage is nowhere near the water.
How you tell
- It fails in irregular flakes and chips, not a band and not a sheet.
- The locations are contact points: around the pulls, along the top edge of drawer fronts, the stile beside the trash pull-out, the door you push shut with a knee.
- Under the flake there is another finish, and it is intact. Often glossy.
- Lift a flake with a fingernail. If it keeps peeling in one piece with almost no resistance, and the back of it is slick rather than fibrous, it never bonded. Tape pressed down hard and pulled off fast says the same thing: a sound finish stays put, a film that never keyed comes away with the tape.
Nothing there is a water problem or a heat problem. It is a preparation problem, built in the day the kitchen was painted.
The grease is usually the whole story
Cooking oil goes airborne and lands on cabinet fronts as a film that builds year on year, heaviest above the range and present on every door in the room. Primer bonds to that film very well. The film is what lets go. Add a catalysed factory finish that was never scuffed to kill the sheen, and the coating is sitting on the surface rather than gripping it.
Touching up will not fix that — the touch-up bonds to the same failed film. Every affected front goes back to something sound, degreased, rinsed, dried, primed and refinished. On one door that is a chore. Across a kitchen it is the repaint again, which is worth knowing before somebody offers to blend it in.
Press the cabinet floor before you decide anything about doors
Empty the sink base. Everything out, flashlight in, and look at the back corners rather than the middle. You are checking for a dark ring, a lifted seam, rust bleeding from a staple line, or a corner gone slightly proud of the rest of the floor. Press it. Hard is good news.
Then dry the trap, the stops and the disposal collar, lay a fresh paper towel under them and go away for a day. A slow weep prints itself. That test decides whether finish work is worth doing yet, because a swollen, darkened cabinet floor is a different symptom with its own causes and it usually arrives before the door does.
Two things plainly. If water is arriving now, that is a plumber's job and it goes first — we do not chase a live leak, we repair what one wrecked after it stops. And if there is a musty smell or visible growth in a cabinet that has been wet, that is a question for an independent testing professional and for the public guidance from the EPA and the Indiana Department of Health. We do not test, diagnose, remediate or abate mold.
Some of this has to be opened up to know. A sink base floor is often a panel on cleats with a gable behind the finished face, and damage travels into the edge of that gable where nothing shows from the room. Until the floor comes out, anyone telling you confidently how far it went is guessing.
Which of these is a Saturday
Genuinely a Saturday, with a sanding block and patience: one door, one lifted bottom edge, core still hard. The match is the harder half — a freshly finished door hung between fronts that have been on the wall for years reads newer in the same color. Edge banding off a shelf inside a cabinet is the same work with nobody looking at it.
Not a Saturday, whatever a video says:
- Any door where the core is soft. Replacement, not repair.
- Thermofoil releasing as a sheet. Re-gluing fails at the cycle that caused it.
- Bond failure on more than a couple of fronts. That is a full strip and re-prep, and half-doing it is how a kitchen peels twice.
- Anything in a cabinet that is wet right now.
What stops it coming back
Stop the water, repair the substrate, then finish. Any other order is why the same door peels a second time.
- Get the leak fixed by a plumber, and confirm it with the paper towel before finish work starts.
- Put a lift-out liner in the sink base. Not to stop water — to hold it where you can see it.
- Seal the cut edges: bottom rails, hinge bores, the holes bored for the drain and the stops. That is the step skipped originally.
- Stop hanging the wet cloth over the door. A bar on the cabinet side does the same job without parking water on an edge.
- On any repaint, the fronts get degreased, rinsed, dried, scuffed and primed. Everything else is a preference. That is not.
Doors that gap unevenly or show a thin line of bare wood at a panel edge in winter are a separate thing — seasonal movement, not peeling.
If it turns into more than a door
Most of these are a door and a plumber. Some are the start of a conversation about the whole run — usually when the sink base is soft, the doors are thermofoil, or an old repaint is failing everywhere hands land.
We do not publish our own prices: a number written before anyone has seen your kitchen is a guess. What we can point at is independent research on this market. Angi, Homeyou and Block Renovation research puts an Indianapolis kitchen project at roughly $18,000–$24,000, with the full spread running about $8,000–$40,000.
Refinishing sound boxes you already own sits at the bottom of that spread, which is why the condition of the sink base matters so much. The kitchen remodeling page sets out the two routes — keep the layout and change the surfaces, or change the plan — and kitchens that went both ways are in recent work.
The short version
Where it started tells you what it is. Edge up and swollen is water. Corner in as a clean sheet is heat. Wherever hands land is a bond that was never made. Then press the substrate: hard means a finish repair, soft means a new door.
Fix the water before the finish, every time. If pressing on that cabinet floor gave you an answer you did not like, ask for an estimate and we will open the doors, take the bin out and tell you what is under there. We look first, then quote.
