Normally I could weigh the sheets and let you know difference, perhaps someone can, but all my sheets are in my caravan, which is full to the door with other stuff as we've just moved house.

You would have prebend the decks to the approximate curve if your going to glass both sides I would imagine.

I've just put the decks on, glass over and down the sides a bit, 3mm ply on the foredeck, 4mm ply on the main and rear decks.

My mossie which was an original kit boat from the 1970's, the platform alone weighed 75kg or there abouts. It was built up to the deck stage and twenty years later, and about 12 years ago now, I followed the original plans and put the 2 x 4mm decks on, not knowing what I do now. I'm planning a restoration next year and the decks will be No1 job when it happens.

Regards