Sliders UK has warned that bowed composite doors are costing installers tens of thousands of pounds in call backs, reputational damage and lost recommendations.

According to the door specialist in introducing timber in increased percentages of the total composite slabs to meet new requirements under PAS24 and Part Q, manufacturers have made it more likely that doors will bow.
This Sliders UK warns is costing installers up to  £400 per call back, with the frequency of those call backs hitting new highs last summer as temperatures soared.
“Composite leaves are using more timber in their construction to address vulnerabilities identified with PAS24 cut-through testing”, explained Steve Mines.
“The problem is that in going down this route, manufacturers have introduced some of the same problems that have afflicted timber doors, and which with no little irony, sales of composites have been founded on.
He continued: “The more timber you use in your composite door the more the slab responds to environmental conditions, particularly expansion with heat.
“We have had customers who’ve been told that 6mm – even 8mm – is an acceptable level of tolerance. If you’ve ever fitted a composite I don’t need to tell you what that’s going to do to the locking mechanism and weather sealing.”
At £400 per call back, some installers according to Mines were going out three or four times to the same job over the summer, with costs running in excess of £1,000 and composite doors taking a rapidly growing share of remedial works.
“The problem is, that it’s not really a problem you can fix”, continued Mines, “If doors are bowing and then contracting by as much as 8mm, how do you accommodate that in its set up?”
Sliders UK’s offer is the Ultimate Composite Door. Launched at the beginning of 2018, it’s available in 23 classic and contemporary styles, including cottage doors.
This uses ‘intelligent timber inserts’, manufactured from 15mm LVL, which are deployed to strengthen the slab at points historically vulnerable to attack in other leaf systems, giving it a PAS24 cut-through test approval.
This means that this technically advanced combination of timber inserts and thermally insulating foam used in Ultimate Composite Doors, delivers on security while balancing it with the core structural stability of the slab – giving it a maximum guaranteed bowing tolerance of just 3mm.

Sliders UK’s Ultimate Composite Door Range has a bowing tolerance of just 3mm

“As long as the door has been fitted properly, as far as we’re concerned if it bows beyond 3mm, we class it as a manufacturing fault and will replace it at our cost”, added Mines.
Available in a choice of Eurocell or Duraflex framing options and arange of 36 premium finishes, with any RAL colour available through Sliders UK’s in house spray painting facility, the Ultimate Evolution also delivers u-values as low as 1.0Wm2.K.
“Slab dimensional stability. Without it, none of the others, the aesthetics, glass choice or anything else, matter because the door won’t perform.

The use of ‘intelligent timber’ inserts means the Ultimate Collection has gained Part Q approval including passing cut-through testing

“Yet installers are being told that a 6mm bowing tolerance is acceptable. As an installer you have to ask at what point to the cost of call backs become too much?”, Mines concluded
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