Interior Wood & MDF Door Inspection China: Solid Core vs Hollow, Veneer & Hinge QC for Importers

A hollow-core door weighs about 15 kg and sounds like a cardboard box when you knock. A solid-core door weighs 30-40 kg and thuds. ⚠️ That 15 kg difference is exactly where Chinese door factories try to save money.

We have inspected 2,000+ shipments of doors and building materials across China. Door core substitution is one of the most common tricks we catch, right behind veneer swaps and hinge screw shortcuts.

The door that looked solid

A US importer ordered 1,200 "solid core" interior doors for a renovation supply chain. The sample they approved weighed 32 kg and felt heavy and quiet. The production units? We weighed 20 random doors and got an average of 14.6 kg. Every single one was hollow core with a paper honeycomb inside.

❌ The order value was $31,200. The buyer renegotiated a 35% refund before the container left the port, then re-sourced from a verified factory. Without the inspection, those doors would have arrived, been installed, and started rattling in every customer's hallway.

Why do factories do it? Because the core is where the money lives. A solid engineered core costs three to four times more than paper honeycomb, and the difference is invisible once the door is painted and hung. On a container of 1,200 doors, that substitution is tens of thousands of dollars of margin hiding behind a slab of veneer. 🔥 The only person who can see it is the inspector who weighs the door before it ships.

Solid core vs hollow core: how to tell

Weight is the fastest field test, but we do not stop there. We also look at the edge profile, check the lock block position, and, where the buyer allows, drill a small hidden hole in a sacrificial door to photograph the core. ✅ One photographed core settles every argument.

What else we check on a door order

Doors are more than a slab of wood. A complete inspection covers the whole package:

Dimensions: height, width, and thickness must match the spec within 2 mm. Doors that are off by a few millimeters cause chaos at installation.

Squareness: we measure both diagonals. A door out of square will never close flush, no matter how good the hinges are.

Glass panels: for doors with glass, we check for cracks, sealant quality, and that the glass spec matches the order.

Fire labels: doors sold as fire-rated must carry the correct marking and test certificate, matched against the actual door.

Hardware kit: hinges, screws, handles, and locks must be counted and matched against the packing list, not assumed.

Cartons: corner protection, pallet strapping, and moisture barriers all matter for a container that sits on a ship for 30 days.

How to spec a door order so inspection is objective

The best inspections start with a spec sheet that leaves no room for interpretation. Put these six lines in your purchase order and the inspector can judge every door against a number, not a feeling.

✅ A spec sheet like this is also your legal ammunition. If the doors arrive wrong, the PO is the document you hold the supplier to. Vague specs are how disputes start.

Step 1: Weigh and knock every sample

Random doors get weighed against the spec and tapped for sound. A 15 kg door labeled solid core is an instant red flag, and we photograph the scale reading as evidence.

Step 2: Check veneer and edge banding

Real wood veneer shows grain variation and depth. Printed film looks flat and repeats. Edge banding must be tight with no lifting at the corners, and we run a fingernail test along every edge.

Step 3: Measure moisture content

A pin meter checks the stiles and panels. Moisture above 12% means warpage risk after shipping, so we test several points per door, not just the edge.

Step 4: Test hinges, screws, and closure

Screws must bite into solid material, not foam. We torque-test hinges, check the door closes flush with the jamb, and verify the gap is even on all three sides.

Step 5: Inspect finish and packaging

Paint, lacquer, or foil defects get photographed and graded. Packaging must protect corners and edges for the container trip, and carton markings must match the packing list.

Real inspection: 5 doors at 14% moisture

On a 600-door order for a hotel renovation, our inspector found five doors at 14% moisture content and eight with veneer blisters under the lacquer. 🔥 Those doors would have warped within two months in a dry climate, and blistered veneer means customer returns.

The factory swapped the affected doors and re-dried the batch. The inspection cost one man-day, $169. Replacing warped doors after installation would have cost the buyer ten times that in labor alone. 💰

The same order also had two doors where the hinge screws stripped straight out of the frame. The factory had pre-drilled the holes too wide, so the screws had nothing to bite into. That fix took an hour on the production line, and a hundred doors' worth of warranty claims disappeared overnight.

FAQs

How can you tell if a door is solid core or hollow core?

Weigh it and knock on it. A hollow-core interior door weighs roughly 12-18 kg and sounds tinny. A solid-core door weighs 28-45 kg and gives a dense thud. In the factory we also drill-check hidden spots or read the edge profile to confirm the core structure.

What moisture level should interior wood doors have?

Aim for 6-9% moisture content measured with a pin meter. Above 12% is a red flag: the door can warp, twist, or split after it reaches your climate, especially in heated or air-conditioned buildings.

How much does door inspection cost in China?

Pre-shipment inspection starts at $169 per man-day, and reports are typically delivered within about 24 hours. A container of doors usually needs one inspection day, sometimes two with full carton opening and moisture checks on every pallet.

What AQL level should I use for door orders?

Most importers use AQL 2.5 general inspection level II for doors, with AQL 1.0 on safety-critical checks like hinge screws and glass panels. Use our AQL calculator to size the sample for your lot.

Can hollow-core doors be used for interior rooms?

Yes, hollow-core doors are common for bedrooms and closets. The problem is not hollow core itself, it is paying solid-core prices and receiving hollow-core doors, or getting a hollow core so thin it rattles when you close it.

Inspect doors before they hit the container

💰 From $169/man-day, reports in ~24h.

See pricing or request a door inspection quote.