Fibre Glass Roof

[tamborine]

Fibre glass has been suggested to cover an old slate tile roof on outhouses. Will it work & how long might it last?

[The Builder]

GRP (glass fibre reinforced plastic) has been around a long time, so it's durability is well established. It's been used to re-line lead valleys - over the top of the existing lead. In fact, on newer houses, GRP valleys are used all the time instead of lead.

I guess you mean resin & glassfibre mat? Rather like the outdated "Turnerising" system where plastic net is spread over the slates, and covered in liquid bitumen.

A right messy job, Tambo, I have to say. Apart from that, your main problem is with the verges. That is, the side (gable) verges, and the bottom fascia/gutter line. I can't see how they can be finished neatly without the stuff looking ragged.

To answer your question: it'll last at least as long as any traditional roof covering. No storm damage likely either. The slates will be held firm.

Also, it'll completely remove the benefit of crossflow roof ventilation, although that is probably not a problem with an outbuilding.

Even with colour pigment added to the resin, it's not going to look good. A bit like a Lego house ;o)

I'll stick my neck out and say that carefully re-nailing the existing slates would not cost squillions.... possibly not a lot more than GRP. Slates re-nailed properly always look good. I'll use modern materials whenever I can, but in some cases ............................ ;o)

[tamborine]

FG on left roof @ £500 ;)

http://i61.tinypic.com/155i844.jpg

[The Builder]

Not a bad price, Tambo. Much bigger roof than I expected. To be honest, it would cost around twice that for a re-nail (both slopes). Largely because I would have renewed the battens at the same time. Also, there would be some slates unuseable, so extra secondhand ones would be needed.

The slate grey colour was the only way to go, and it looks better than some I've seen. I still think the verges and fascia line look a little ragged though.

Also, a re-nail would have straightened out the fascia/gutter line. Guttering is going to be a problem on there now. The right hand verge is very tatty, sadly. Where repairs have been made (rather roughly), the covering just doesn't look right. For a little extra cash, they should have fixed that first... then coat over a nice, flat surface.

It's just an outbuilding after all. No storm worries now :o) I would hesitate to do this to a dwelling though. Surveyors and mortgage people don't like traditional materials covered in this way. They worry about what is being hidden ;o)

A good job for the price, Tambo, but I can't help but appreciate the building on the right, which has had a nicely done re-nail.

[tamborine]

Theyre past their sell by but will be saved as long as I live, then all will be sold/developed to pay IHT :(