I don’t think many will argue that triple glazing has failed to take off within UK fenestration as many thought it would. Hailed as the natural successor product to double glazing, it has failed to take any decent sized market share and various myths about the product have been busted since.
This is the state of triple glazing. And a poll too!
A novelty upgrade
Triple glazing was supposed to be the product that installers could command better prices and margins for. The natural step up from double glazing and the supposed cure to noise and the further reduction of heat loss.
That was a while ago. Fast forward back to today, and it has become little more than a novelty upgrade for some installers. I have seen numerous offers from fairly large installation companies offering triple glazing as a “free” upgrade. Obviously it won’t be free, the cost will be hidden somewhere in the contract price. But that is where triple glazing is now at. A novelty upgrade from installers to help land a sale.
Hype was immense. The marketing spin around the product was just as busy. But when the realities came to home, it became clear that we might have all been getting a bit too excited about the prospects of triple glazing.
In the end, it turned out that there was no tangible heat saving benefit until you got to 44mm triple glazed IGUs. Also, there was no noise benefit if you used equal glass and cavity thicknesses. You could achieve all of that, at less weight and cost with a high quality DGU. Yes, if you put a triple glazed IGU on steroids you could squeeze some extra benefit out of it over a double glazed unit, but the cost wouldn’t warrant it.
Then there is the climate. We’re a cold, rainy country with the ocassional heatwave. Yes our weather is becoming more extreme in terms of flooding, heat, drought and wind, but I wouldn’t say we’re seeing extremes in cold. Not in the same way some European and Scandinavian countries do. Cold like that commands a highly specified triple glazed window to genuinely give climate control. Here, a couple of degrees below freezing isn’t enough.
I appreciate it gets colder than that in Scotland and sales of triple glazing there may well be higher than the national average. But on a UK-wide scale, we simply don’t have the weather to warrant large volumes of triple glazing.
Bohle warning
In a recent press release to the industry, Managing Director of Bohle Dave Broxton had this to say on the subject of centre-pane failures:
The use of low e on face 3 of the unit as part of its thermal make-up, can lead the middle pane in a triple-glazed unit to heat up far more than it would do in a standard double-glazed unit”, said Dave Broxton, Managing Director, Bohle.
This increases the pressure on the glass. In larger units this is less of a problem as the glass can flex and the pressure can be absorbed.
Within smaller units with shorter edges, the glass is, however, essentially too stiff to bow out and it can lead to stress cracking of the centre pane or failure of edge-seals.
The study is consequently focussed on the importance of edge-quality in defining the structural integrity of the glass – and its ability to withstand thermal stress.
An EU funded study is now under way to investigate centre-pane failures on triple glazed units and a focus on edge quality and how the glass is cut. Bohle are providing expertise in this study and the report is due to be published later on in the year.
Higher or lower?
To try and find out the current state of triple glazing in UK fenestration, there are a couple of quick polls to answer before you head off to the rest of your day.
In the first, I simply want to know whether you think triple glazing has been a success or not. In the second, I want to know if you plan to sell more triple glazing this year than in previous years or not. I’ll post these polls across my social media platforms and aim to get as big a sample as possible. I may even email my database and ask for some participation.
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I found in the early days of the “boom” majority of homeowners have strayed away from triple glazing down to the misinformation given by “sales people” and making it look like a sales gimmick. Nowadays when I get asked for triple glazing I always ask the question why and 8/10 people want noise reduction and find out it is what other companies have told them. I always steer them in the direction of a properly spec’d double glazed unit which having knowledge usually wins the order.
We are approved distributors for Scandinavian system which only does triple glazing for sliding doors, we often sell their triple glazed windows to match. Really the only time we supply triple glazed.