Sofa and Sofa Bed Assembly: Legs, Frames and Mechanisms
What to expect when assembling a sofa or sofa bed: attaching legs and arms, modular sections, fold-out mechanisms and delivery access tips.
Many sofas arrive partly assembled, but plenty need arms, backs and legs fitting at home, and sofa beds add a mechanism that has to move reliably for years. Knowing what is involved helps you plan the delivery and the time.
How sofas arrive
Boxed and flat-packed
Smaller and modular sofas often arrive in several boxes with frame parts, cushions and a fixings bag. Assembly is a mix of bolting, clipping and sometimes stapling.
Delivered in pieces
Large sofas may come as separate sections that must be joined: left arm, right arm, corner unit and ottoman. Check the orientation of each part before connecting.
Fully built
Some arrive assembled apart from legs. Access is then the main concern, as a rigid sofa may not get through awkward doors or around stairs.
Before you start
- Measure the route and the final room.
- Unpack in a clear area, preferably on the carpet or a sheet.
- Check that all pieces are present, including fixings and legs.
- Keep cushions in their wrapping until the frame is fully assembled.
Typical build
- Join sections. Use the connecting brackets or bolts supplied, ensuring edges are flush.
- Attach arms and backs. Align the pre-drilled holes carefully, and tighten gradually.
- Fit legs. Tip the sofa gently onto its back or side, with help, and screw in legs by hand. Fit the central support leg if there is one.
- Stand and test. Place on its feet, and check it is stable and does not rock.
- Add cushions. Finally, insert them and plump.
Sofa bed mechanisms
Pull-out and fold-out types
The frame unfolds to create the bed. Mechanisms include metal frames, springs and slatted bases. Check for sharp or pinch points and follow the manufacturer's instructions.
Click-clack and clic frames
The back folds down flat, and the seat slides. Check the back locks at each position.
Testing
Open and close the mechanism several times before putting bedding on. Listen for stiffness, and ensure it locks fully in both positions. Check the mattress sits correctly when open.
Common mistakes
- Overtightening bolts into particleboard or screw-in frames.
- Fitting legs of unequal length or wrong orientation.
- Forgetting central supports, which can cause sagging.
- Assembling in the wrong room where the sofa will not fit through the door.
- Removing the cushion covers too early and getting them dirty.
Getting the sofa into the room
If a sofa will not fit, check whether legs, arms or backs are removable. Some arms unclip, and legs unscrew. Measure the diagonal depth for stair turns. If a sofa still will not go in, contact the supplier. For heavy items, an assembler or helper can make the job much safer. See furniture delivery and access tips.
Hiring help
Corner sofas, large modulars and sofa beds are awkward for one person. Tell the provider what you have, send a photo, and say what is needed: just legs and joining, or the full build. See how much assembly costs.
A worked example: a corner sofa in three pieces
Suppose you have a three-piece corner sofa that arrives with legs, connecting brackets and a set of loose cushions. Measure the route first. In the room, lay the sections down in order, fit legs to each piece (often two people, one lifting), then link the pieces using the brackets or clips, tightening gently. Fit the cushions last. It can take around 30 to 60 minutes in total, as a general guide, depending on the design.
Checks after assembly
- Sit on each section and check nothing creaks or shifts.
- Run your hand along the join to check brackets are seated.
- Open and close sofa-bed mechanisms several times.
- Look for loose feet or stray screws below the seat.
- Check the legs are even and the floor is protected.
Common mistakes
- Lifting by the arm or back, which can strain joints.
- Dragging a sofa on its legs and splitting them.
- Forgetting to remove transit straps and protective cardboard in the mechanism.
- Using the wrong screw length in legs.
Protecting floors and walls
Use furniture pads or a blanket under legs while moving, and lift rather than drag across wooden or tiled floors. If the sofa sits against a wall, leave a small gap so the back does not mark the paint. For help with getting items through narrow spaces, see furniture delivery and access tips.
Choosing a time to build
Build a sofa when you have a clear room and two people. Fitting legs on a large corner unit is awkward alone, and cushions or covers can wait until the frame is stable. If a sofa bed is arriving, test the mechanism straight away so any fault can be reported to the supplier within the window the retailer gives.
Frequently asked questions
Do I need tools to fit sofa legs?
Often just hands or a basic spanner or hex key. Some legs screw into pre-fitted inserts, while others need a few screws. Check the booklet.
How do I stop a sofa bed from squeaking?
Check all bolts are tight, then look at moving points. A light lubricant used as the manufacturer allows, such as on metal joints, can help. Avoid getting any on fabric.
Can I assemble a corner sofa alone?
Small sections can be moved by one person, but joining and lifting large units is safer with two.