Many composite doors are prone to bowing and warping if they are put under too much thermal stress.
This usually happens when the inside and outside temperatures are dramatically different. For example, if a front door is installed next to a radiator, during the winter the inside face could get very warm, while the outside may be barely above freezing. Similarly, the sun shining directly onto a dark-coloured door can cause the outside of the door to become much warmer than the inside, regardless of the season.
This difference in temperature means the door wants to do two things at the same time: contract because it is cold, and expand because it is warm. These two stresses can cause the door to warp and twist if not managed properly.
“If you speak to installers of doors, many of them understand that it is a common problem, and offer tips to homeowners to deal with it, such as keeping the door in the locked position so that the frame keeps the door in shape,” says Nigel Headford, Director at Deceuninck Aluminium. “But then we shouldn’t be telling people how to use their doors.”
Some installers advise homeowners not to use dark colours on their doors if they are south-facing, but they risk losing sales if the homeowner has their heart set on a particular style.
“But it’s not just certain colours people are moving away from,” Nigel says. “The bowing issue on some doors has affected sales of composite doors altogether, directing homeowners to aluminium alternatives, which have bowing tolerances built in – along with other advantages.
Available in a range of flush and glazed-in door slabs, with contemporary flush sash options across 21 styles and 30 insert panel options, the Decalu88 Entrance Door forms part of a complete range of
products from Deceuninck Aluminium. These include the Decalu88 bi-fold, Decalu163 lift-and-slide patio as well as options for casements.
Designed to handle sash weights of up to 150kg, it is compatible with the same marine grade finish and dual colour option that is available as standard across the Decalu range, and it shares the pre-rolled high-performance polyamide thermal-breaking system.
It has also been engineered with unique ABS inserts that are specifically designed to manage changes in temperature.
This allows the internal and external faces of the Decalu88 Entrance Door to expand and contract independently, which means that even when it’s subjected to temperatures as high as 80ºC, bowing is limited to just 2.5mm.
At the other end of the scale, the temperature can drop to as low as -30ºC and Decalu’s design means that it will not deflect more than 3.5mm.
“Composites are inherently compromised with their design because they are made up of different materials, a PVC outerframe and an engineered timber or foam filled slab in a thermoplastic skin,” explains Nigel.
“That makes them extremely sensitive to even the slightest change in temperature. If you’re an installer and you’re fitting a dark-coloured door on a south-facing property, you can almost guarantee that it’s going to move, no matter how much adjustment you make.
“Looking at some of the comments on social media forums for installers, you can see the weariness with which some of them return to jobs because of the bowing, even if homeowners have been keeping their doors in the locked position.
“With margins already squeezed because of supply issues, these are call backs installers could really do without.”
Another reason for choosing an aluminium door from Deceuninck Aluminium is that it complies with the changes to Part L that come into force in the summer, when the minimum requirements for replacement windows and doors will increase to 1.4W/m2K. In newbuild, U-values will drop to a 1.2W/m2K.
“In this day and age, we shouldn’t be expecting homeowners to deal with issues that should have been designed out of doors,” Nigel concludes. “And the Decalu88 Entrance Door in an all-round perfect fit.”
For more information call 01249 816 969, email firstname.lastname@example.org or visit www.deceuninck.co.uk