Backed by a 10-year warranty, including for warping, Apeer’s 70mm composite door range is designed to help installers sell with confidence, explains managing director, Asa McGillian.

The UK experienced a record-breaking heat wave this May, with temperatures in London surpassing 35C and highs of 32.2C registered in Cardiff and Flintshire.

And while the sunshine was welcomed by many, the unseasonable heat once again highlighted how unprepared the UK is for such events, particularly our housing stock, which has traditionally been designed to cope with far less dramatic changes in weather.

Modern fenestration products can of course help to make homes more comfortable but even these may struggle to perform under extreme conditions – with poor quality composite doors by far the worst offenders when exposed to excessive heat.

Warping and bowing are the Achilles heel of composites, and the constant bugbear of installers who deal with the time-consuming remedial work and risk of poor reviews from frustrated homeowners – and it’s a problem that’s only got worse with the growth in popularity of dark coloured finishes and the increase in hot weather.

So why are some composite doors so prone to warping?

It all boils down to the fact that they are constructed from a variety of different materials, which can include a timber or foam core that’s sandwiched between a glass reinforced plastic (GRP) skin, held together by adhesives, supported (in some cases) by metal reinforcement and installed in a PVC frame.

All these will react differently to temperature changes, so when exposed to high levels of sunlight, the outer face will want to expand, the cooler internal face will be more stable, and the slab can then twist as the materials fight against one another.

It’s a problem that’s exaggerated on south facing properties, and exacerbated even further on doors that are finished in colours that will naturally absorb rather than reflect sunlight such as anthracite grey, black, brown or blue.

It’s also an issue that can be made worse by poorly designed composites that allow moisture ingress, for example around glazing apertures, on cut edges or due to bad seals – once that moisture has made its way into timber-based elements it can cause swelling and further reason for the slab to distort.

Over time, all this excessive twisting, warping and bowing can result in doors that don’t open and shut properly, hardware that becomes misaligned and a product that eventually becomes so out of shape that it’s no longer fit for purpose.

The Apeer Anti-Bow Warranty
At Apeer, we know just how much of an issue bowing is for installers, you only have to take a look at the online forums or talk to fitters, to understand their frustrations. After all, composite doors should represent a relatively quick and profitable sale, they should leave homeowners happy, open to larger projects and ripe for positive referrals.

That’s why we offer a 10-year warranty on our doors, that includes warping. The reason we can confidently offer this guarantee is that we engineer our high performance 70mm doors around a steel reinforced GRP sash that is designed to deliver exceptional structural strength, so it will retain its shape and stay fully operational, even when subject to changing temperatures.

This commitment to our customers is supported by decades of experience in the sector (we launched our original foam filled, double rebated and triple glazed as standard 70mm door at Glassex in 2004!) and continual investment in product innovation and manufacturing excellence.

That includes the introduction of lean manufacturing processes across the entire business, to constantly find those small improvements that help to build on our product quality and service, and which has already resulted in 98.7% of orders delivered and installed without issue.

For inferior composite door products, warping and bowing will always be a problem, especially as we see more extreme weather conditions become the norm.

For Apeer customers however, our extensive, class leading 70mm composite range continues to provide a high-quality solution, one that’s designed to be sold and fitted with confidence.