Fit a bathroom privacy lock

Fit a turn-and-release privacy lock to a bathroom door, working the lock into the door edge and the keep into the frame.

BPL-01Check the job and buy the right lockIf replacing an old lock, measure the backset (distance from the door edge to the spindle hole centre) so the new lock matches, usually 44mm or 57mm. Buy a bathroom privacy lock set with a turn knob inside and a coin or screwdriver-slot release outside, sized for your door thickness (most doors are 35-44mm). This lock only fixes into the door and its timber frame, not into the wall, so it works the same whether the wall behind is brick, block, timber stud, metal stud, dot-and-dab, or lath and plaster.

RULES

1 each · Bathroom privacy lock set (turn and coin-release)

Buy:B&QAmazon

1 each · Tape measure

Buy:Tooled UpB&QAmazon

1 each · Pencil

Buy:Tooled UpB&QAmazon

KNOW THE RULES

If this door is a certified fire door (common in flats and some new builds), check the label. Fire doors need fire-rated hardware to keep their rating under Building Regulations Approved Document B, so buy a lock sold as fire-door compatible.

BPL-02Remove the old lock, if there is oneUnscrew both round plates (escutcheons) and lift them off, then slide out the spindle. Unscrew the faceplate on the door edge and pull the latch body out of its mortice. If the old screw holes don't line up with the new lock, fill them with wood filler and let it dry fully before you drill anything new.

1 tube · Wood filler

Buy:B&QAmazon

1 each · Filler knife

Buy:Tooled UpB&QAmazon

BPL-03Mark and drill the spindle holeHold the new lock against the door edge at a comfortable height, usually around 1000mm from the floor, and mark the spindle centre through the template supplied with the lock. Drill straight through the door face with the size bit stated in the lock's instructions, typically 18-22mm, going slowly from one side then finishing from the other to stop the wood splintering. Then mark and chisel a mortice in the door edge so the lock body sits flush.

1 each · Flat/spade drill bit, 20mm

Buy:Tooled UpMachine MartB&QAmazon

1 roll · Masking tape

Buy:Tooled UpB&QAmazon

BPL-04Fit the lock body and spindleSlide the lock body into the mortice and screw the faceplate flush to the door edge using the screws supplied. Push the spindle through the lock body so it sits centred and turns freely. Don't overtighten the faceplate screws, as this can bind the mechanism.

1 each · Screwdriver bit for drill/driver

Buy:Tooled UpB&QAmazon

BPL-05Fit the turn knob and release platesFit the inside plate with the turn knob over the spindle and screw it in place. Fit the outside plate with the coin-slot or screwdriver release the same way, checking the spindle engages both sides evenly. Turn the knob a few times before fixing fully home to check it moves the latch smoothly.

BPL-06Mark, cut and fit the keep in the frameClose the door gently to mark where the latch meets the frame, then mortice out a shallow recess so the keep plate sits flush with the frame face. Offer up the keep and check the latch slides in and out cleanly before screwing it into the timber frame. Screws go into the frame's own timber, not the wall behind it, so this step is identical regardless of the wall type.

1 each · Wood chisel (already owned)

Buy:Tooled UpB&QAmazon

BPL-07Test and adjust the fitClose the door and turn the lock from inside, then test the emergency release from outside with a coin or flat screwdriver. If the latch is tight or loose in the keep, widen or reposition the recess slightly with a small file. Check the door still closes and latches smoothly with no sticking.

1 each · Small flat file

Buy:Tooled UpB&QAmazon

BPL-08Tidy upVacuum wood shavings and dust out of the mortice and off the floor. Wipe down the door and frame, and dispose of the old lock and packaging. Put tools away and give the new lock a final test before you finish.

1 each · Dust sheet

Buy:Tooled UpB&QAmazon

Tooled Up and Machine Mart links are affiliate links: if you buy after clicking, we may earn a small commission at no extra cost to you. B&Q and Amazon links are plain searches and earn us nothing.

Save this as a project

Back to all guides

Related guides