Re: Re: Irish say no to PVC windows
@Kevin 123 wrote:
In twenty years…. all a quality pvc window will need is an occasional cleaning.
Some of my postings may have been slightly tongue in cheek but this makes a Shinner pontificating on Irish neutrality sound persuasive.
Wooden windows are â€œidealisticâ€? Stained softwood six stories up may be optimistic but idealistic?
Firstly security: I know of at least two timber window systems readily available in Ireland that have a Secure by Design licence requiring testing to BS7950. Timber doors with PAS 23 & 24 ratings. Likewise timber AOVâ€™s tested to BS 476-22.
Most modern timber windows have a â€˜flush jointâ€™ sash rather then the â€˜covered jointâ€™ sash of prevalent in plastic windows. The flush joint is inherently harder to pry open.
Insulation: The best plastic windows have poorer U-values then the best timber windows. (Admittedly 28mm glazing – and associated convection heat transfer – isnâ€™t going to help your case either but then again the traditional upvc marketing spiel was â€œdonâ€™t worry about the mechanical joints, just feel my cavity widthâ€¦.â€). Timber windows with a U value of 1.0 are available!
Maintenance: Go back to the beginning of the thread and see the link to the LCA from Mohammad Asif et al at Napier for interesting data on the useful service life of plastic windows. Likewise similar data published by Islington Council last year (https://www.islington.gov.uk/democracy/reports/reportdetail.asp?ReportID=2345)
also gives a circa 25 year useful service life for plastic windows. The report goes on to state; â€œbased on the experience of maintenance needs with existing housing stock, Camden Council estimate a life expectancy of 60 yearsâ€ for timber windows.
One of the few times I would regard timber windows as impractical is when windows canâ€™t be reached from a cherry picker â€“ in these situations give serious consideration to alu-clad timber. None of those stained finishes has a warranty worth the name and opaque finishes will most likely need refinishing after 7/8 years.
If you want to take this discussion into embodied energy content, end of life disposal and environmental impact etc, be my guest. I would contend this aspect of fenestration is even more important given future energy usage and associated factors. Thatâ€™s when the idealism comes into it and increasingly, realism.
Is mise le meas,