Based purchase of house on inspection. House had some obvious signs of water damage on ceilings, so roof was a priority for inspection. Richard Gaughan from National inspected house and gave all clear for water damage, except a small part of roof with old shingles(he estimated cost at $1500-2000), and specifically said water damage problem was not on-going. Renovated house, discovered severe roof problems, and had to replace entire roof as water leaked from roof into house constantly, even in light rain. Roofer showed me BARE PLYWOOD visible on roof and roof peak with no shingle capping and said "you'd have to blind to miss the roof problems". Interior reno delayed until roof was fixed, some joists had to be replaced as they were rotted by water. Cost of unanticipated roof repair - $7000+, other repair costs still being determined ($80000+). Spoke with Richard, who offered no solution/apology. Said he provided a "valuable service" and could only examine what was visible/accessible, despite our concern re: water damage and roof. Richard was very professional during inspection and offered suggestions, which really proved to be irrelevant. I'd like to know about the roof, not that the building code requires railings for my deck that was higher than 2 feet! Will never hire this company again!