Blame the Low Bid, Not the Roof To the Editor: I read with interest the article on page 7 of the May issue entitled "Flat- Roofed Schools Get Bad Rap in Mass." Apparently, the sponsors of Bill H1080 did not thoroughly research flatroof problems. If a roof is properly designed and if proper materials are specified, properly used and properly installed, that roof will not leak and will last as long as a sloped roof. I believe the sponsors are addressing the wrong problem, as not all flat roofs leak. I believe the problem is with the government's bidding requirements in having to accept the "low bidder." If there are a few bad or questionable legislators, are we to