Flat roof covering

I did my garage/kitchen/porch with EDPM a few years ago (adjusted all roofs to the same height and re-boarded at the same time)

I'm always careful to wear soft shoes and check for stones lodged in the soles before waking round on it (when clearing gutters, adjusting satellite dish etc).

I've noticed a bit of lichen has started growing in the last year or so, might give it a wash to stop that getting much further.

Rubber (butyl IIRC) is supposed to be better than felt.

Metal will generally last a long time, *if* the pikies don't nick it!

GRP/Fibreglass. Any number of suppliers eg

Mostly they are varieties of canned snake. Some such as Topseal are simply standard products (fibreglass in their case) sold in a very expensive way.

'Tis true but with Topseal at least the installers are supposed to be trained and monitored by Topseal to do a good job. ie. not just a bloke buying the stuff trade and slapping it on without really understanding the product, how to mix/apply it and under what weather conditions.

From recent experience I trust my builder and heard via another route he has used this Topseal installer before. Of course the installers may well vary in abilty/standards...

From the replies thus far, GRP seems to be favoured. My follow-up question is: what is a typical cost/sq metre of installing same?

(I'm not looking for quotes, just enough for budgetary estimation)

Their kit cost, plus whatever trim and tools you will need gives a quick answer.

The raw materials for a 2-layer roof would cost around £300 for 15sqm. but d-i-y may be beyond me.

Any ideas what a Topseal installer would charge overall?