Old Roof on an Old House

I just wanted to add an update to the roofing article I posted a day or two ago. About 40 years ago I lived in a house that was built about 80 years before. It had the original wood shingle roof. the roof was in perfect repair and had never needed repair. The shingles were hand split and were attached to 1x3 purlins spaced at 12 inches on center. These were attached to 4x8 beams.  If you stood in the attic during daylight hours you would see sunlight shining through spaces in the shingles. If you were in the attic during the heaviest of Florida rainstorms you would find no leaks. This type of roof lasts a very long time. Part of the secret of this type of roof is that the back side of the shingles were open to air so that they could dry. The other important factor is that the shingles were split and not sawn.