Don’t cut corners
Alan Burgess, managing director of Masterframe Windows, responds to an article written by Kurt Greatrex, sales director of Dekko Window Systems, who said installers should steer clear of non-glass-bonded, unglazed Residence 9 windows, which appeared in last month’s Glass Times.
Like Kurt I too remember the early days of PVCU. Sadly for me mine date back to the mid-1960s when household names like Crittall Hope first took tentative steps towards plastic. At that time, Trocal and Miplam sections had un-galvanised steel reinforcement, because it was thought no rain would ever touch the steel. However, the steel reinforcement created its own moisture by sweating inside the sealed chambers, which created rusty steel.
So, he is right to be cautious. The industry has fought hard to shed its poor image from the 1980s, however, there are several issues here: glass bonding, steel reinforcement and construction methods.
Like Kurt, I have ensured Masterframe leads by example. A rated, SBD and fully steel reinforced sashes as standard shows that it is possible to achieve security and great thermal properties – it just means we must incur significant other costs like krypton to balance the heat lost through steel reinforcement.
The danger with these arguments is that it suggests one cost saving measure (no steel) is better than a perceived loss of weld strength using a new concept offered by competitors.
I fully accept that any ‘on site operation’ can never be controlled better than factory conditions. I also accept that glass bonding seems to be the way forward for those seeking to reduce material costs (no steel), but products would be even stronger (and expensive) were reinforcement retained, and sashes glass bonded.
While windows from fabricators not using steel reinforcement and glass bonding will look identical, it’s obvious that they’ll perform far worse, expect service issues, and will create further reputational damage for both company and industry.
Selling to high-end consumers in the heritage market, installers have found products lacking. Homeowners in this sector own expensive houses, they don’t want a repeat of the same mistakes early PVCU created. Today’s buyer is better educated, they know about foils, plant on bars and monkey tailed handles. What’s more, they are much more willing to purchase top end products, providing they like what they see, trust the company, and believe new windows will be an investment.
What they dislike immensely is the diagonal weld line right across the corner, or mechanical joints that are open to the elements. What they want is a wooden window, with authentic wooden joints, without the hassle of wooden windows. In other words: they want a foiled PVCU window that looks the same as wood, with old fashioned handles, a wood grained surface, and (most importantly) butt joints inside and out.
Therefore, fabricators have a few choices when it comes to corner joints:
- Stay with 45° welded – strong, easy to manufacture, but obvious that it is plastic.
- Mechanically joined profiles, glued and screwed corners – strong, but usually open ended.
- External timber look, (ETL) – a welded solution with a butt joint on one side, and no license fees.
- Timberweld – a welded solution with the same timber look appearance, but on both sides.
Most people who’ve seen Timberweld acknowledge that it’s the prettiest jointing method on the market (that’s why we patented it back in 2005). However, those unhappy with paying a license fee tend to suggest its reason is weld strength.
Obviously, removing two faces of profile has to reduce the weld strength. However, as interest develop,s and this method is adopted by profile companies, so profiles change and additional components are inserted to add back the missing strength.
The all-important advantage of a product that incorporates Timberweld technology is that it is beautiful and authentic, looking every bit like an original timber window and giving the impression that it has been lovingly produced by a master craftsman.
So, perhaps the ideal world is one where fabricators insert steel reinforcement, bond the glass into place and weld the corners with Timberweld resulting in strong, durable and beautiful, timber alternative windows.
Anything less is cutting corners.