Standard v "premium" resin and other fibreglass roof material questions

[andykent]

So, I'm starting to draw up the shopping list to replace my leaking, end-of-life zinc flat roofs with fibreglass. Both parapet, one 2m x 2m area with no access, one approx 1.5m x 0.65m that could potentially have a chair put on it occasionally. I'd like the new surfaces to be around for a couple of decades.

One of the supplier websites I've looked at lists both standard and premium resin. What's the difference? Is the premium one likely to be worth the extra money?

Some suppliers are recommending 450g matting and some 600g. Recommendations of the amount of resin I will need vary from 5kg to 9kg. Which are right for my requirements?

Depending on the weather there may be a few days or a few weeks between attending to each section. Are there any issues with a resin tub having been opened across this timespan?

Thanks, Andy

 

[Rufus Raintight]

Hi Andy,

Here goes

Standard vs Premium

In order to cheapen the product some companies offer a “standard” or “low-cost” material which hasn’t been specifically adapted for the market and could be an inferior grade product. Always go for a premium flexible system.

450gm or 600gm fibreglass

Anything under 5 square metres you can use 1 layer of 450gm fibreglass, and for anything over that its either 1 layer of 600gm or 2 layers of 450gm.

more information on glass fibre usage: http://grproofing.com/guide/fibreglass-matting/

Resin Usage

Depending on the type of glassfibre you choose will depend on the amount of resin needed. For 600gm use approx 2.5 litres per m² and for 450gm its approx 2 litres per m²

Open Resin Tins

You won't have any problems with open cans, all GRP Roofing systems are made using polyester resin which requires a catalyst to activate just mix them well before use. Correctly stored the GRP roofing resins will last over 2 months.

Hope this lot helps

Cheers,