Bi-fold and sliding doors are a feature of many modern UK homes and extensions — and the door frames, sills and thresholds of these large systems take regular knocks from furniture removal, house moves, renovation work and everyday use. Chips, scratches and dents in UPVC and aluminium door frames are common, and rather than replacing an expensive door system, professional surface coating repair can restore the appearance at a fraction of the cost. This guide covers what’s possible for bi-fold and sliding door frame repair.
UPVC Door Frame Chip and Scratch Repair
White and woodgrain UPVC door frames chip and scratch from impact. Chips in UPVC expose the paler substrate beneath the coloured surface layer, making them visible. Repair involves filling the chip with a compatible filler compound, colour-matching to the UPVC surface and finishing with appropriate surface coatings. White UPVC is the most straightforward to repair invisibly; coloured or woodgrain UPVC requires more careful colour and pattern matching.
Aluminium Frame Chip and Anodised Finish Repair
Aluminium bi-fold door frames — particularly popular in their anthracite grey, black and powder-coated finishes — chip and scratch to reveal bare aluminium beneath. Repair uses colour-matched surface coatings applied to the chip or scratch area, matched to the specific RAL or BS colour of the frame. Anodised aluminium finishes (where the colour is electrochemically bonded into the surface) are more challenging than powder-coated finishes — matching the translucent metallic quality of anodised finishes requires specialist coatings.
Threshold and Sill Chip Repair
The threshold bars and sills of bi-fold and sliding doors take the most wear, as they are the primary traffic point. Chips in aluminium threshold bars can often be filled and colour-coated successfully. For severely worn or corroded thresholds, replacement of the threshold component may be more practical than surface repair.
When Repair Is the Right Choice
For isolated chips and scratches on door frames and sills that don’t affect the door’s function, repair is almost always the right choice — bi-fold and sliding door systems are expensive to replace, and the frames and sills are typically available as separate components only from the original manufacturer, making like-for-like replacement difficult. Repair delivers a visually restored result quickly and at far lower cost.
