Fix a letterbox flap that sticks or rattles

Diagnose why your letterbox flap sticks or rattles, then fix the hinge, seal or fixings so it closes cleanly.

LB-01Work out what's actually wrongOpen and close the flap a few times. A rattle usually means loose screws, a worn brush seal, or too much gap between the flap and the letterbox body. Sticking usually means paint build-up on the hinge or edges, a bent flap, or the letterbox sitting slightly out of line with the door. Knowing which one it is tells you what to buy before you start.

LB-02Gather your tools and materialsYou'll need a screwdriver that matches the screw heads (usually flathead or Pozidriv), fine sandpaper, and a paint scraper. Buy a replacement brush draught excluder strip if the flap rattles, or a replacement flap/hinge kit if it's bent or worn out. Lay a dust sheet under the door to catch old paint flakes and screws.

1 each · Screwdriver (flathead and Pozidriv)

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1 sheet · Fine sandpaper (120-240 grit)

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1 each · Paint scraper

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1 each · Dust sheet

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LB-03Prop the door open and remove the flapProp the door fully open so it can't swing while you work. Undo the screws or nuts holding the letterbox plate to the door — most letterboxes have an inner plate that's bolted through to the outer flap. Keep the screws safe in a small pot; you'll likely reuse them.

LB-04Clean up the door and letterbox bodyScrape off any built-up paint around the letterbox cut-out and the hinge itself, then lightly sand the edges smooth. Wipe away dust and check the cut-out in the door is still square and not swollen or split. This step alone fixes a lot of sticking problems caused by old paint.

LB-05Fix a rattling flapTighten every screw and nut on the letterbox plate — a rattle is very often just a loose fixing. If it still rattles, fit a new brush draught excluder strip along the inside of the flap; this cushions the flap and stops the metal-on-metal knock. If the flap has a weak spring or worn hinge pin, replace the whole flap unit rather than trying to repair the hinge.

1 each · Letterbox brush draught excluder strip

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1 each · Replacement letterbox flap/hinge kit

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LB-06Fix a sticking flapIf sanding and scraping haven't freed it, check the flap isn't bent — lay it on a flat surface to see. A bent flap should be replaced rather than forced straight, as it will stick again. If the letterbox itself sits crooked in the door, unscrew it fully, realign it, and fill the old screw holes with wood filler before rescrewing in a slightly different spot.

1 tube · Wood filler

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1 pack · Brass wood screws (assorted sizes)

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LB-07Refit the letterbox and test the actionScrew the plate back on evenly, not overtightened, so the flap can move freely. Open and close it 10-15 times to check it swings cleanly and sits flush when shut. If your door is a fire door — common on flat entrance doors onto a shared hallway — any letterbox fitted must be a certified fire-rated unit, not a standard replacement.

RULES

KNOW THE RULES

Fire doors (including flat entrance doors onto communal areas) must keep their fire rating under Building Regulations. Only fit a certified fire-rated letterbox on a fire door — a standard flap breaks the certification.

LB-08Add a squirt of lubricant and tidy upPut a light spray of silicone lubricant on the hinge pin to keep it moving smoothly and stop future squeaks. Sweep up paint flakes and offcuts from the dust sheet, and bin any old, bent flap. Wipe the door down and you're done.

1 can · Silicone lubricant spray

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