"CL "dnoyeB" Gilbert" wrote in message
...

I need to make a lid for my Cistern. I plan on using some 2x4s and
perhaps
3/4" plywood. I am wondering if I paint this, will it take on any measure
of weatherproofness?

If not, how do i make wood weatherproof.

Nothing makes wood "waterproof" if exposed to serious
rain when horizontal. Your best bet would be to design
a sloping roof (for rapid runoff) and emulate either a
house roof (shingled) or a ship's hatch (treated tarpaulin
tight over a wood frame, exposing no wood to the weather.)

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)