Flat Roof Replacement - BETAELAST - ever heard of it ?

In the process of getting a roofer to replace the felt on my garage, kitchen extension and front porch. He's provided me with a quote and on the quote it states that he will be replacing the decking with plywood and fitting 3 layers of felt comprising of Betaelast and Betaelast M/W (could be Betaelast MIW, hard to read writing). That's all it says and I have no idea what Betaelast is.

I had a quote from another roofer prior to this and he has spec'd plywood plus 3 layers built of 3b glass felt, 2mm underlay and 4mm cap sheet but this came in at nearly three times the cost of the Betaelast quote.

Slightly concerned as to the difference in prices I asked another roofer about the difference in materials Betaelast and he said he'd never heard of it. Has anyone ever heard of Betaelast, is it kosher quality stuff or is this the reason for the significant difference in pricing ?

Also, roofer 1 says that Betaelast is mineral coated and that I won't need chippings due to this - is this the best option ?

I don't know much about it but I has a look at my bitumen spec's handbook and the website is here which is design in Italy.

Is it possible to have a low pitch roof instead of flat roof for trouble free maintenance?

not really at this stage as i've been quoted 2000-3500 for the pitched roof alone and obviously the garage and kitchen extension would still need refelting so it takes it way out of my price range at the moment.

i did say to him that i'd considered having a pitch roof and he said if that was the case then he could just put one layer of felt down if i wanted

I wouldn't do any less than 3 layers of felt, if leak, it will be mess internally. I would get a few more quote.

Do you know how many square metre of flat roof you have?