Every summer, homeowners across Essex and Suffolk run into the same problem: uPVC doors that were perfectly fine in spring suddenly start sticking, jamming, or refusing to lock properly. In most cases, it’s a problem that can be fixed quickly without replacing the door.
Why Do UPVC Doors Stick in Summer?
UPVC expands when heated. On a sunny day, a south-facing uPVC door can reach surface temperatures above 60°C. The British Plastics Federation notes uPVC can expand by up to 3mm per linear metre for every 20°C rise (Source: British Plastics Federation, 2024).
6mm
of potential vertical expansion on a standard uPVC door during a hot summer day – enough to cause sticking, jamming, and lock misalignment. (Source: British Plastics Federation, 2024)
The 4 Most Common Causes
Hinge wear that allows the door to drop when it expands, worn rollers on sliding or bifold doors, lock misalignment where keep and latch no longer line up, and gasket compression where swollen seals create too much friction.
What You Can Try Yourself
Check if the door operates normally in cool morning temperatures. Check hinges for visible sag. Try lubricating the lock mechanism with dry silicone spray.
When to Call a Professional
Call a professional if the door won’t lock at all, if the frame appears warped, if the problem returns each summer despite adjustment, or if the multipoint locking mechanism is stiff or grinding. The Master Locksmiths Association notes forced lock repairs account for approximately 15% of emergency summer call-outs (Source: Master Locksmiths Association, 2024).
What a Professional Repair Involves
A typical sticking door repair takes 30 to 60 minutes and costs between £65 and £120, including toe-and-heel adjustment, hinge adjustment, lock realignment, and gasket inspection.
Preventing Summer Door Problems
In April or May, lubricate all locks and hinges with silicone spray, check the gap between door and frame is even, and ensure gaskets are clean and flexible. Contact Plastic Doctor at plasticdoctor.co.uk/contact-us/ for a same-week booking.
