Assembling flatpack cabinets is more straightforward than many people expect. With the right approach, tools, and techniques, you can achieve professional-quality results while saving significantly on installation costs.
Whether you're a confident DIYer or a first-timer, these tips will help you assemble your cabinets like a pro.
Before You Start
Inspect Your Delivery
When your flatpack cabinets arrive:
- Count all packages against your delivery note
- Check for damage to packaging or visible panels
- Open and inspect before your return window expires
- Report issues immediately to ensure prompt resolution
Gather Your Tools
Quality assembly requires the right tools:
Essential:
- Cordless drill/driver
- Phillips head bits (quality ones)
- Square for checking alignment
- Tape measure
- Pencil
- Soft mallet or rubber hammer
- Spirit level (600mm minimum)
Helpful additions:
- Cabinet clamps
- Right-angle drill attachment
- Magnetic bit holder
- Knee pads (you'll be on the floor a lot)
- Good lighting
Prepare Your Workspace
Set yourself up for success:
- Clear a large, flat area for assembly
- Protect floors with drop sheets or cardboard
- Have good lighting
- Work at a comfortable height where possible
- Keep packaging until assembly is complete
The Assembly Process
Step 1: Read the Instructions
Yes, really. Take 10 minutes to:
- Review all steps before starting
- Familiarise yourself with component names
- Understand the sequence
- Note any warnings or special instructions
Step 2: Sort Components
Lay out all pieces for one cabinet:
- Identify each panel
- Check all hardware is present
- Group similar items together
- Keep small hardware in zip bags or containers
Step 3: Assembly Sequence
Generally, assemble in this order:
- Join base and sides
- Attach back panel
- Add top panel
- Install internal components (shelves, drawers)
- Attach doors last
Never skip steps or work out of sequence.
Step 4: Hardware Tips
Cam locks:
- Insert cam bolts first, tighten firmly
- Cam locks face the correct direction
- Turn to lock, stop when tight
- Don't over-tighten
Dowels:
- Apply a tiny amount of PVA glue
- Insert fully into holes
- Align before pushing together
- Wipe excess glue immediately
Screws:
- Pre-drill if not pre-drilled
- Don't over-tighten (strips holes)
- Use correct length always
- Keep screws upright for access
Step 5: Checking Alignment
As you assemble, constantly check:
- Panels are flush at corners
- Cabinet is square (measure diagonals)
- Components are level
- Doors hang straight
Fix issues immediately - it's harder once the cabinet is complete.
Common Mistakes (And How to Avoid Them)
Mistake 1: Rushing
The problem: Hurrying leads to misaligned panels, stripped screws, and frustration.
The solution: Take your time. A well-assembled cabinet takes 30-60 minutes. Budget accordingly.
Mistake 2: Not Checking Square
The problem: Out-of-square cabinets cause door alignment issues and installation problems.
The solution: Measure diagonally corner to corner. Both measurements should be identical. If not, gently rack the cabinet until they match before tightening fully.
Mistake 3: Over-Tightening
The problem: Stripped cam locks, cracked boards, and damaged finishes.
The solution: Tighten until firm, then stop. If something starts to resist, don't force it.
Mistake 4: Wrong Side Up
The problem: Panels assembled in wrong orientation, visible raw edges, incorrect door swing.
The solution: Check orientation before each step. Labels often indicate top/bottom, inside/outside.
Mistake 5: Ignoring the Back Panel
The problem: Loose or incorrectly fitted back panels cause racking and instability.
The solution: Ensure the back panel sits properly in grooves all around. Pin or screw as directed.
Door and Drawer Adjustment
Even perfectly assembled cabinets need door and drawer adjustment.
Hinge Adjustment
Quality hinges (like Blum) offer 3-way adjustment:
Height (up/down): Loosen the mounting plate screws slightly, adjust, retighten.
Depth (in/out): Use the screw at the back of the hinge arm.
Side (left/right): Use the screw at the front of the hinge arm.
Drawer Adjustment
Drawer runners also adjust:
Height: Using clips or screws on the cabinet side runners.
Tilt: Adjust front fixing point up or down.
Side-to-side: Loosen, shift, and retighten.
Installation Considerations
Once assembled, cabinets need proper installation:
Floor Cabinets
- Check floor level
- Use packing to level cabinets
- Screw together through sides
- Secure to wall where possible
- Check level after each addition
Wall Cabinets
- Locate wall studs
- Use appropriate fixings for wall type
- Don't rely on plasterboard alone
- Level and plumb is crucial
- Use a ledger strip for support during mounting
Benchtop Installation
- Benchtop sits ON cabinets
- Seal any joints with silicone
- Allow for expansion
- Secure appropriately
- Check level before fixing
When to Call a Professional
DIY isn't for everyone or every situation. Consider professional help for:
- Complex layouts with multiple angles
- Stone benchtop installation
- Gas or electrical appliance connection
- Major plumbing relocations
- Very heavy items
- Time constraints
Many trades specialise in flatpack installation at affordable rates.
Troubleshooting
Doors won't align
- Check cabinet is square
- Verify cabinet is level
- Adjust hinges systematically
- Check for warped doors
Drawers stick
- Clean runners
- Check for obstructions
- Verify drawer is square
- Adjust runner alignment
Gaps appear
- Check all cams are tight
- Ensure back panel is fully seated
- Verify panels aren't bowed
- Re-tighten in sequence
Need Help?
At Arc Interiors, we want your project to succeed. That's why we provide:
- Detailed assembly instructions
- Video guides for common tasks
- Phone support during business hours
- Parts replacement if needed
Still unsure? We can recommend trusted installers who'll assemble and install your cabinets professionally.
Contact us with any questions - we're here to help!