HWL Trade Frames has said that all of its pre-existing Residence 9 accounts have switched to buying in non-glass bonded frames.
The specialist trade fabricator has led the development of an R9 frame-only offer, pioneering the application of Timberweld sash-welding technologies in its manufacture.
This allows HWL to deliver a 90° external and internal butt weld, emulating the appearance of a traditional timber flush casement or mechanically jointed sash.
At the same time, because it’s also stronger, HWL says the welded sash doesn’t need to be glass bonded – a process used in traditionally mechanically jointed R9 sashes to increase their structural strength.
Graham Howatson, director at HWL Trade Frames, said: “We carry out regular weld tests as part of our quality control process. The Timberweld unglazed R9 head weld consistently stands up to up to 11 bars or 1100kN/m2 of pressure. That’s consistent with a standard inline PVC-U welded product which ranges from 9-12 bars (900kN/m2 – 1200kN/m2).
“What you get far beyond the ‘standard’ is the 90° butt weld inside and out, so that it looks exactly the same as a mechanical joint but with no requirement to glass bond for strength because it’s already there.
“That delivers a series of benefits to installers. Handling is easier, fitting is exactly the same as a standard PVC-U window, you can buy your glass from your usual supplier and remedial work is much more straight forward. It’s a win all round and every single one of our pre-existing customers has switched onto it without exception.”
In addition to its own in-house testing conducted in partnership with the Residence Collection, the HWL window was put through its paces under PAS24 at the beginning of May by independent testing house, Exova,
This returned a series of clear passes under PAS24 test requirements for mechanical load and manual intervention testing.
These results came less than month after BS EN 6375 – 1 Weather Test results, completed in April, again by Exova. This gave HWL’s R9 non-glass bonded window an Exposure Category of 1600, a Class 3 Air Permeability Rating (600pa); a Class 9A (600pa) Water Tightness Rating; and top Class C4 (1600pa), resistance to wind.
Howatson concluded: “It’s not that we’ve abandoned glass bonding or aren’t offering it anymore. It’s there if any of our customers want it.
“What is unequivocal is that once they buy and then fit a non-glass bonded frame they don’t look back because it saves them time, makes their lives far easier and can save them anywhere upwards of £500 per install.”
