heeelllooo and welcome superwood  

welcome aboard
trying to work out whether this post is out off genuine interest or self publicity

if its out off interest then fair enough

if its self interest  then its quite close to being spam
if its not intended as spam then i appologise and look forward to another chippy on board

Actually, we're probably just talking about the timber equivalent of a upvc conservatory, aren't we? The sections of that are just mechanically jointed and silicone sealed. Any opening lights would surely be constructed with traditional joints, mortice and tenon on the 'quality' ones and dowelled on the cheaper options, as per the door industry?

As for overall quality of 'bespoke, hand-built' and 'flat-pack', I've been called in to repair some pretty ropey hand-built affairs built by guys with more front than trade skills, so it's a tad dodgy to label all of either mode of construction in the same way. There's always an element of trust involved, some of it misplaced - more's the pity for the trade.

I'm sure Supawood will enlighten us when he gets back from his weekend's gliding.

Interesting stuff, but I’m not sure about its appropriateness on this side of the trade boundary, if the intent is just to educate those of us you assume are in a position to influence opinion.

As to the link:

"The rebate height is very important, which should be a minimum of 15mm for double glazing in a wooden frame, and the fitting a double glazed sealed unit into a standard wooden frame, with a 12mm rebate height designed for single glazing, is asking for trouble.  Also the rebate depth in wooden frames is often insufficient to allow for beading, and if a double glazed sealed unit is puttied in like single glazing, then again you are asking for trouble."

Any wooden window maker who puts only a 12mm rebate into their sashes hasn't been making windows long enough to have learnt that double-glazed unit manufacturers have a job getting each pane of the unit aligned. It doesn't take long to come to the conclusion, just by dint of experience, that 15mm is the minimum you can allow.

Likewise the gap at the bottom of the unit will come anyway as a result of raising the unit so that the top and bottom spacers align with the frame by the same amount.

Unless the window is a vertical slider, I always use an 18mm rebate, if only to allow for the tolerance insisted upon by the unit manufacturer, which can be up to 3mm overall, although my current supplier makes them precisely to size - usually. On a vertical slider the rebate has to be 15mm for the glazing bars to be narrow enough to be both proportional and strong enough.

As for fixing and sealing the units - after the window has been treated with a water repellent (if softwood) and primed with two coats of acrylic primer (if to be painted), a bed of acrylic sealant (silicone isn't overpaintable) is run all around the rebate onto which the unit is pressed until it oozes out of the frame. A run of sealant is then run along the edge of the frame and around the unit level with the top of the spacer bar. The ends of the bottom bead is then smeared with sealant and pushed into place until the sealant oozes out along its entire length, the bead is then gently tapped along its full length with a small rubber mallet, increasing the pressure on the bead and its bed of sealant. A squirt of sealant is put onto the corner of that bead and the second length of bead fitted, the process being repeated around the full perimeter. Whilst the bulk of the extruded sealant is skimmed off with a spatula, the sealant is left to cure overnight and the now cured but flexible sealant is trimmed back flush with the frame with a Stanley knife.

There are no gaps as there are with rubber gaskets, the unit is totally sealed into a frame that can expand and contract in the most severe exposure location and won't leak. Drainage holes in windows fitted with rubber gaskets are there because the glazing is EXPECTED to leak; the whole system is designed to take water away from the vent. Well-constructed wooden windows are designed to stop water getting in in the first place.

Whilst I sympathise with your frustration at the perceived ignorance of the timber men and their obdurate refusal to accept change, you're saying that they should be giving their customers the choice between what they're familiar with and with something new. But the other factor is that for a hell of a lot of people the choice of a wooden window is making a statement about what they believe in; it isn’t all about cost, it’s only about cost when their choice is between timber and upvc, but as a “traditional window” man I wouldn’t be having that conversation because they wouldn’t be speaking to me, they’d be speaking to a upvc guy or a window fitter flogging Wickes’ stuff. They’re talking to me because they like the windows I’ve made for their friend, or because they’ve seen my van outside the house I’ve just fitted windows in. That’s timber vs. upvc.

As for traditional timber vs. timber system. Again, the people I see like the idea of something made in the traditional way, albeit with modern equipment – but a mortice and tenon joint is still that whether made with a tenon saw and chisel or a table saw and morticer. I’m not about to disabuse them, because I happen to share their view. And whilst I’ll concede that there might well be a time when the ‘new’ wood would be very useful in some applications, as eighty-five or ninety per cent of my customers expect traditional materials worked by traditional methods, the remaining fifteen or ten per cent hardly amounts to a revolution worth half a barricade.

And then, of course, many of us came into the woodworking business because it was the woodworking part that attracted us, not the business. You don’t come into it expecting to become rich in anything other than quality of life. I am as happy as a pig in manure in my dilapidated medieval barn, intimately surrounded by machinery that would be lost in an industrial unit. I make a good living and have a good reputation, the latter essential for the creation of the former. I’m not really up for a revolution, and although I’ve got a business degree, it’s really only served to inform me how bloody lucky I am to have made the choice(s) I did so long ago. I’ve worked in the upvc industry, managing the production side of the fourth largest replacement window manufacturer in the UK from 1985 to 1989, and I can be as scathing about the upvc window industry’s ignorance of the timber side as you say they are of us. Their ignorance, compounded by an arrogant disregard for architectural heritage, driven by greed, is nothing to feel good about.

I would take issue with you on…

“ALL pvc windows these days are made from tested & certificated systems with millions of pounds of development behind them. This will get worse (for the wood window business) when Window Ratings become mandatory.”

My experience over the past few years is that a significant number of people are actually REVERSING the trend to upvc and replacing them with timber windows of a design that would have originally been found on their house. The whole of a local housing development is also fitted with timber windows. Any estate agent will tell you that an older house will sell quicker if it’s still got its original fenestration, even faster if it’s got timber windows of a traditional design with double-glazing and full weather- and draught-proofing.

“I admit to an interest in this, as I have been bashing my brains out trying to market a tried and tested easy-to-assemble system, and the responses above demonstrate the ignorance of what is, in reality, a very complex subject, and the preconceptions that make it so difficult to get it to market. “

Whilst you seem to have had a stressful 35 years banging your head against a brick wall, I’ve had a great 35 years, none of them characterised by complacency. And my BCOs know exactly what they’re looking at when they see a fully compliant timber window.

It might have helped if you assumed that we all feel the same way about bad window makers. Representatives of the various upvc systems rubbish other upvc systems, the only common ground seems to be their contempt for wood, but you can’t blame them for getting so defensive, they are under siege.

Phew! So many issues raised by Joiner and Woodsmith: There are some serious misunderstandings here that need dealing with.  I have been busy this evening, it's late now, and I will be out all day tomorrow, but I'll be back.
I too have had stuff disappear into the ether while I'm still writing, so I now prefer to compose in Word then copy and paste.

Cheers
~K

This still doesn't answer my question;

If ventilation is vital how come so many dg units in ventilated plastic windows fail prematurely?

There is actually “general recognition of the issues involved”. What I’m having a real problem with is getting my head around the appropriateness of the issues on here.

You seem to be working under a misapprehension that we – tradesmen, as against ‘the industry’ - can make a difference on the scale you deem necessary with the limited (either by choice or force of circumstance) resources available to us.

I cannot envisage any of the joiners on here finding themselves in “private households that would quite possibly prefer wood, but which have been persuaded that wood cannot meet their requirement. And I don’t mean just on price.” They, and I’m projecting my own daily working experience here, simply find themselves in households that prefer wood and are prepared to pay the premium implicit in the material and skills to work it. I should have said ‘skills and the imagination to work it into something to be proud to own’, because one thing about bespoke joinery is that it usually means precisely that – tailored both to the individual desires of the customer and the scale and proportions dictated by the historical character of the house. (Zambezi can offer independent testimony to that, because he was present as an observer when the customer expressed a delight in her new windows that went beyond just pleasure in having got rid of her old rotten ones. I don't know anyone who's said they can't stop going upstairs to look at their new upvc or system-built windows.)

I don’t doubt for one second that you regret the defacing of the Edwardian terraced houses in your street, but it isn’t something that can be laid at the door of the “woodworking fraternity”. Try aiming at the failure of your local authority to slap a Conservation Area order on the road and apply an Article 4 directive, a piece of legislation designed to prevent exactly what you decry. Conservation area status itself cannot prevent the installation of upvc. Article 4 removes the permitted development rights that do.

As for the supply of tropical hardwoods. You won’t find anyone on here arguing for their use to “cater for the mass market”, if only because no one on here caters for the mass market.

The “high cost of traditional skills” is misleading, certainly in the area of vernacular architectural work, like windows. I charge £150 a day, out of which I pay for a workshop, van, machinery, tools, which would add up to a very nice three grand a month (£36,000 a year? still pitiful by the big boy's standards), except that it doesn’t. I’m lucky if I get in three and a half days productive work a week due to surveying, ordering, fetching, all the unpaid work that falls to the sole trader. I quote on the basis of £150 a day and I do add a margin determined by my experience of similar jobs and the kind of otherwise unforeseen problems likely to crop up whilst working on older buildings and that does translate into profit. I doubt whether anyone on this forum would recognise what they charge as “high cost” in comparison to what’s earned by directors of woodworking businesses manufacturing system-built windows. It’s probably why they’re still in business whilst system guys go broke almost as if it’s a condition of their Articles of Association. We each, system manufacturer/window maker or bespoke joiner, charge what our respective markets will bear. I pay myself a reasonable wage and continue to refine my skills, system manufacturers have a tendency to exploit their workforce and deny them the opportunity of learning a skill by de-skilling the process needed to make their windows in order to employ an unskilled workforce to generate profit. (Bit of Marxism for you there.) A 1200 x 900 double-glazed casement window from me would cost around twice what you’d pay at Wickes or Magnet. Difference is, it’ll last three or four times as long. It would also outlast any upvc window. One of my oak casement or sash windows will still be there when all our grandchildren are long gone, even if the occasional failed unit has been replaced in the interim.

De-skilling is one of the significant impacts of system manufacturing. Skilled trades are hanging in there largely because of their own efforts to promote the benefits of self-employment in their respective trades, but it’s an uphill struggle against the forces in education that have removed vocational training from the curriculum. How can anyone learn to appreciate the properties of structural materials whilst sitting in front of a computer terminal designing something for their CDT project. Had we not got system manufacturing then there would be at least a dim prospect of an apprenticeship within a system that required a future supply of skills. To me, yours is a self-fulfilling prophecy in a way, because once all the traditional skilled guys have gone the alternative they represented will have gone with them. In which case, if the upvc guys do eventually take over the whole market we won’t be around to complain about it.

On the specific issue of drainage, no one is disputing that an incorrectly fitted unit is at risk of premature failure. What you persist in avoiding is addressing the issue of premature failure due to manufacturing faults. We can only speak as we find, even if it is in the face of academic opinion. I’m personally not inclined to crusade on behalf of any glazing technique, I just get on with it because it works and has proved to work over time – a long time. Like a lot of other guys, I’ve not only learnt from the bad experience of others, but taken note of the warnings that came out of the industry concerning sealant for glazing over twenty years ago.

If applied wisely, avoiding contact with the edge of the unit, then acrylic is effective. It does have an acetate component which, if it comes into contact with the edge seal, can compromise the unit’s integrity, but I have yet to have a unit fail due to the sealant used. The ONLY units I have had fail have done so within days (and in one case, hours) of fitting due to faulty manufacture. On removal of the bead (difficult) no sealant had reached the edge of the unit, as evidence the bead of sealant from the separator line to a few mil of the edge. And I leave that sealant there (after photographing it) to deflect any attempt by the manufacturer to avoid liability by blaming it on me! A few have tried, but I never use them again - wouldn't have used them in the first place if I'd known their processes were so crap. (I've never had a single failed unit with my current supplier, who I've been using for almost five years.) And incidentally, I NEVER have taped edges, having seen units fail (none of mine, but on jobs I’ve been called in to rectify) because of failure of that taped edge, when WATER has worked under the tape and caused the unit to break down on BOTH upvc and timber, but especially on upvc because it’s easier for the water to get past the gasket in an older window.

There is a tendency to guarantee units in timber windows (however constructed) for only five years. But then manufacturers, generally, only guarantee their units in upvc windows for ten years. What’s that saying? The first upvc windows I replaced with double-glazed timber vertical sliders were on the severe exposure rear elevation of a house in Warwick. I guaranteed them until Steve got his invitation to my funeral. He never called me back in the fourteen years since the job was signed off and sold the place a year ago with no problems with the windows. That industry guarantee might appear to support your contention that only a system-built window will perform, that it will earn the right to that ten year guarantee, but it’s my contention that the only WINDOWS that will fail are the badly made ones. But good or bad window, we all know that units will fail if they haven’t been made properly. But I guess it helps if you have someone else to blame and can cite a sheaf of research to substantiate your arguments. Lucky old upvc industry. Pity about all the adverse research contradicting their claims of longevity for their products, which no one on the systems side of the timber window industry makes much of. Can’t think why.

I’m frankly not interested in “rolling back pvc”. It’s a tide you won’t reverse. I really don’t have a problem with upvc per se, as long as it’s use is confined to new-build, in the same way that I no longer have a problem with anything I can’t do anything about. I really wish you all the best luck in the world in what you’re trying to achieve, but providing a “mass-market alternative”, especially for “the big specifiers”, isn’t really me. Personally. I’m an “average chippie” and a complacent bastard who seems to have spent half his life campaigning to change the world and who’d now like a bit of peace and quiet.

But feel free.

That's true Greg. There's little, if anything, we can do as micro businesses to get the message of Accoya across, only the big boys have the resources to do that.

But the fact remains that Jo Public is blasted by ads for upvc and are undoubtedly taken in by the offers of finance, despite a £3,300 set of windows ending up costing them over eight grand at the end of ten years. If they weren't, the upvc companies couldn't afford to keep up the advertising!

As I said in the Trade section, the cost of Accoya doesn't make it a contender on price alone. It'll be competing with the hardwoods in the unpainted market. And when it comes to a choice between their pockets and the enviornment we all know which one wins.

Still, the alternative is out there and it costs us nothing to offer it.

More than a tad patronising.

You would definitely be better off on something like the Green Building forum where you'll find an abundance of kindred souls.

We sole traders, running our 'lifestyle' businesses, will just continue blundering on.

If you’d bothered to read my posts you’d see that I was far from outright dismissive about Accoya, far less than you’ve been about “us”. If anyone has the blinkers on, it’s you. Since your Damascene conversion it would appear that the rest of us have become heretics for doing little more than put your convictions to the test. It would appear that we’re too far off-message for the disciples of the new religion. Possibly because some of us have been shown the light before and found it of too low a wattage.

Acetylated wood is not new. Some people have used radiation to create the polymer; others used heat. Accoya uses vinegar, which oak is already full of. The US Forest Products Lab has a patent on heating oak to over 250 F to change some of its chemistry. They also press it at the same time to improve many of its properties.

You’ve yet to answer any of the questions put to you directly. Well, if you can’t be bothered I don’t see why we should hang around waiting.