How to Install a uPVC Door
9 Steps That Get It Right

The 9 installation steps

1. 1

   Prepare all tools and materials

   Gather a drill, screwdriver, tape measure, spirit level, rubber mallet, shims, screws and wall plugs that match your wall type, anti-mould silicone, and personal protective equipment before you start.

   • Electric drill with masonry and wood/plastic bits, plus a screwdriver.
   • Tape measure, carpenter's pencil, steel square, and a spirit level (one as long as the frame is more accurate).
   • Rubber mallet, wooden or plastic shims, and screws with wall plugs that match your wall type — solid masonry, lightweight panel, and aerated concrete each need different plugs.
   • Anti-mould silicone with a caulking gun (or PU foam), and a chisel or router for the hinge recesses.
   • Safety glasses, gloves, and a dust mask.
   • Stopping mid-job to find a missing tool is how mortar and foam set at the wrong moment — lay everything out first.
2. 2

   Measure the opening and check the site

   Measure the width at 3 points and the height at 3 points, and use the narrowest and shortest values as your reference. Then compare both diagonals to check whether the opening is out of square.

   • Measure the width at the top, middle, and bottom — use the narrowest value.
   • Measure the height at the left, centre, and right — use the shortest value.
   • Measure both diagonals; a big difference means the opening is out of square and must be corrected or compensated for first.
   • Measure the wall depth so the frame sits flush, check the threshold is level and clear, and make sure no water pipes or electric cables run where you will drill.
   • If the opening is not a standard size — common in renovations — a door can be manufactured to the actual opening instead.
3. 3

   Assemble and set the frame plumb and square

   Assemble the three sides of the frame, lift it into the opening, wedge it with shims, and check plumb and level with a spirit level. Fix it with screws and wall plugs (dry fit) or mortar (wet fit).

   • Assemble the two side posts and the head into a frame, corners tight, using the kit's fixing points.
   • Lift the frame into the opening and shim all four corners so it sits slightly off the floor.
   • Check both posts for plumb and the head for level, adjusting with shims, then confirm both frame diagonals are equal.
   • Dry fit: screw and plug each post at 3 points minimum (top, middle, bottom), working top-down. Wet fit: pack mortar around the frame and let it set before hanging the door.
   • Re-check the level after every screw — driving a screw can pull the frame out of true. Do not overtighten, or the frame bows inward and the door binds.
4. 4

   Recess and fit the hinges

   Mark matching hinge positions on the door edge and the frame, chisel each recess exactly as deep as the hinge leaf, and always drill pilot holes before driving screws.

   • Use 3 hinges per door, or 4 for a tall or extra-heavy door.
   • Mark hinge positions on the door edge and the frame from the same reference point (the top of the door) so they line up exactly.
   • Chisel or rout each recess to exactly the thickness of the hinge leaf — too deep and the door will not close flush; too shallow and it presses against the frame.
   • Drill pilot holes before every screw so the material does not crack and screws stay centred.
5. 5

   Hang the door on the frame

   Lift the door against the frame with shims supporting it. Drive only one screw per hinge first so you can still adjust the position, then fit all remaining screws once the door sits correctly.

   • Lift the door against the frame with a helper or shims under the door.
   • Drive one screw per hinge on the frame side first, so the door can still be adjusted.
   • Swing it gently to check it meets the frame squarely, then fit all remaining screws.
   • Never leave the door hanging on one hinge or with screws missing while you take a break — its weight will strip the screw holes.
6. 6

   Adjust the gaps and test the swing

   Even out the gap around the door on every side. Open the door to about 45 degrees and let go — if it swings on its own, the frame is not plumb yet.

   • The gap (reveal) around the door should be even along the top and both sides, with floor clearance to suit the room.
   • If the top gap is wider on one side, the door is tilted — adjust at the hinges or the frame shims.
   • Open the door to about 45° and let go: if it swings closed or open by itself, the frame is not plumb yet.
   • Open and close it several times — no rubbing, no scraping sounds, no dragging on the floor.
   • For bathrooms, leave a ventilation gap at the bottom or choose a louvred door.
7. 7

   Install the knob and lock set

   Mark the knob height, drill from both faces towards the middle to prevent chipping, fit the latch and strike plate in line with each other, then test locking and unlocking.

   • Mark the knob height — matching the other doors in the house looks best.
   • Drill the knob hole slowly from both faces towards the middle so the surface does not chip, then drill the latch hole in the door edge.
   • Fit the latch, assemble the knob on both sides, and fix the strike plate on the frame in line with the latch.
   • Test locking and unlocking until it works without catching.
   • Order from us and we drill the knob hole at the factory, free — no on-site drilling needed.
8. 8

   Seal with silicone and tidy up

   Fill the gap around the frame, clean the joint so it is dry and dust-free, then run anti-mould silicone along the frame-to-wall joint on both sides. Smooth the bead and wipe off any residue.

   • Fill the gap between frame and wall with PU foam or mortar, and trim flush once dry.
   • Clean the joint until it is dry and dust-free — silicone will not bond otherwise.
   • Run anti-mould silicone along the frame-to-wall joint on both sides, especially for bathrooms and exterior doors that must keep water out.
   • Smooth the bead evenly, remove any masking tape and protective film, and wipe off pencil marks and residue.
   • Keep the joint dry and the door lightly used until the silicone has fully cured (see the tube's instructions).
9. 9

   Final check before use

   Confirm the door opens and closes smoothly, shuts with no light showing through, locks easily, has an even gap on all sides, has every screw fitted and tight, and has a continuous silicone bead.

   • Opens and closes smoothly with no rubbing or scraping.
   • Closes flush against the frame with no light showing through.
   • Locks and unlocks easily, latch seating fully in the strike plate.
   • Even gap on all four sides; every hinge screw fitted and tight.
   • Silicone bead continuous with no breaks, especially at the threshold; no scratches, stray holes, or glue marks on the door face.

Caring for a uPVC door after installation

• Wipe clean with a damp cloth — no repainting, no polishing needed.
• Avoid hard impacts and do not hang heavy items on the knob.
• Check the hinge and lock screws for tightness from time to time.
• Inspect the silicone joint once a year; if it starts peeling, strip and reseal.

Installation questions, answered