see previously cited research on your 1st thread...

"...A survey has been carried out by the present research team with the help of local housing authorities, architects and surveyors throughout the UK to determine the maintenance characteristics, durability and service life of various window designs. The present survey, and of a number of other studies carried out by various organisations, have produced almost identical results showing that aluminium clad timber windows are the most reliable choice. Statistical analysis of the survey results reveals average service life of 47 years for an aluminium-clad timber window. Aluminium and timber windows have been reported to be almost similar in terms of their service life, 43 and 40 years respectively, whilst PVC-U windows, being the least durable, have a service life of 25 years. As shown in Figure 7 (see page 25), aluminium clad timber, aluminium and timber windows are expected to last well beyond the described service life...."

J

I'm about to replace the restored original sashes into their refurbed original box frames in one of the kitchen windows some time this week. Bit of filler in the meeting rail and a new pane of glass to replace a cracked one (a golf ball smashed the other), three coats of primer/undercoat, two top coats and they should be good for another 160 years. Not bad for softwood ('Baltic pine') with just the cill of oak.

My neighbour's 1990s pine window frames lasted less than 15 years. Now replaced by some rather tasteful woodgrain-effect pvc.

guess there are good and bad examples of both wood and pvc out there. Wont find examples of pvc lasting 50+ years as it hasnt been around long enough. Not sure this tells us anything about how long the frames that are being produced today will last.

I like wooden windows and boats, but have decided to switch to plastic as life is too short. I consoled myself that PVC is not a 'natural' material to make a window out of, but then neither is glass.

I was looking at a timber frame house recently, built in the 60's, and the timber windows installed in that property were not only sound and in good condition, but still looked great and worked perfectly. At the ripe old age of 45 (ish not 100% sure when the house was built) they are still in tip top knick. There is no reason that they couldn't go on for another 45 years. Although the glass was a thin 2g unit, I didn't see any reason a better 2g or even a slender 3g unit couldn't be retrofitted in the existing frames.

Having said that, I know the owners of the house did take excellent care of them, having them professionally re-painted when required (or sooner!).

http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport/5575.pdf ...



J

http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport/5575.pdf

Got it now. Thanks.

(Strange that Jim's link, despite looking exactly the same as the two following, still won't work.)

And should have none

Well spotted that man!

(The Greater Spotted Url. First sighting this year?)

Posted By: GaryBSeret

The pipework is very unusual - it is a forged layered iron of 5mm wall thickness (sample pipe was 1" bore) with a high phosphorus content. The technique was used for high quality rifle and shotgun barrels (Damascus Twist was the term used by the specialists).

I'm familiar with Damascus barrels, very dangerous things, should never be fired with modern loads. Interesting that it's proved so resistant to corrosion though.

Posted By: ShevekWhat's the life expectancy of timber-only vs. PVC windows?
15-25 years for PVC? 50 for well-maintained timber?

To an extent you answered your own question. If well maintained, why would the wood windows come to the end of their life? Unfortunately, house maintenance is something most folks seem not to do, just replace when totally knackered. UPVC's life is fairly fixed but is dependent on things such as exposure and orientation.

What precisely is it that makes a uPVC window reach the end of its life? Plastic embrittlement? Fittings failure? Old fashioned looks? Why is it that timber windows would seem to be less prone to scrappage due to 'old fashioned looks'?

Just expediancy taking hold over perfection

Pragmatism - action or policy dictated by consideration of the immediate practical consequences rather than by theory or dogma

that sound's about right to me

The British Plastics Federation says:
"Faults on windows using PVC-U profiles occur usually in the operating mechanism or the seals, i.e. the components that are not made of PVC. Hence the long term characteristics are determined by the durability, low maintenance and wear characteristics of the components installed into the PVC window frames, and not by those of the frame itself. Since the PVC window frames do not have to be painted with fungicides or protective coatings, no maintenance of the frame is required apart from cleaning"

Anecdotally, our PVC windows are 20 years old with no major problems. Even on the south side, where they get full sun*, there's no sign of cracking or yellowing that I can see. Minor problems are: Gaskets discoloured. One lock mechanism part broken due to burglary, so must be left fully locked (not left open a crack).

In comparison, we have a 10 year old wooden door+frame which is getting spongy in places (bottom of frame is worst). It's being regularly painted, and I've even drilled&injected wood preserver into it, but I can see it's just a matter of time. Poor wood, and poorly installed. Grrr.

*not this year:-(