Why is my uPVC door or window difficult to open or close in hot weather?
uPVC naturally expands when exposed to high temperatures and direct sunlight. During particularly warm weather, this heat expansion can cause windows and doors to become stiff, difficult to operate, or appear misaligned. When temperatures approach 30 degrees uPVC products can thermally expand up to 2cm.
This is a normal characteristic of uPVC and does not necessarily indicate a fault with your product.
Is my door or window broken?
In most cases, no.
If the issue only occurs during periods of hot weather and your window or door operates normally when temperatures are cooler, the product is functioning as expected. Once temperatures reduce, the uPVC will naturally contract and return to its normal operating position.
Are darker coloured uPVC frames more affected?
Yes.
Darker coloured uPVC frames absorb and retain more heat than lighter colours, making them more susceptible to heat. However, lighter coloured frames can also be affected when exposed to prolonged periods of sunlight and high temperatures.
What can I do before requesting an inspection?
We ask customers to try the following simple cooling measures before we arrange a visit:
- Step 1 – Apply a cold, damp cloth
Dampen a towel or cloth with cold water and hold it against the face of the affected window or door for several minutes. This can help reduce the temperature of the uPVC and improve operation. - Step 2 – Spray with cold water
If available, use a garden hose to spray the external face of the frame with cold water. This can help cool the product more quickly. Please note: Pressure washers should never be used on uPVC windows or doors. - Step 3 – Allow temperatures to reduce
If the product has been exposed to direct sunlight throughout the day, operation will often improve naturally as the sun moves and temperatures begin to fall.
Will my door or window return to normal?
In most cases, yes.
As temperatures cool, the uPVC contracts and returns to its normal dimensions. This generally restores the normal operation of the window or door without the need for any adjustments.
Why don’t you recommend adjusting the hinges immediately?
Adjustments made during unusually hot weather can create new issues when temperatures return to normal.
If hinge adjustments are carried out while the uPVC is expanded, further adjustments may be required during cooler weather or seasonal temperature changes. This can lead to unnecessary inconvenience and additional visits.
For this reason, we recommend allowing the product to cool and return to normal operating conditions before considering any remedial work.
Does this mean there is a defect with my uPVC product?
Not necessarily.
Heat-related expansion is a normal property of uPVC and can occur during periods of extreme heat. All uPVC products are designed and tested to perform within normal temperature ranges. Temporary operational changes during exceptionally hot weather are generally not considered a product defect.
When should I contact you again?
If you have followed the cooling steps above and the issue persists after temperatures have reduced, please contact us and we will review the matter further.
A simple test
If heat expansion is the cause:
- Try the door early in the morning before the sun hits it.
- Try again late evening after it has cooled.
- If it suddenly works normally when cooler, expansion is likely a major factor.
If the door:
- Remains jammed after sunset
- Won’t open the next morning
- Or the handle feels loose, spins, or won’t fully lift
Our team will assess whether additional investigation or attendance is required.
