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Show Barn Roof Most Vulnerable " To Weather of Any on Farm The roof on the main barn usually is more vulnerable than I any other farm building roof. Among the reasons for this are: 1 To facilitate drainage, the barn generally is situated on the highest ground in the farmstead. As a result it is fully 5 exposed to wind and other elements of the weather. . - 2 On almost all farms, the main barn is the largest building and has the greatest roof area. 3 Because the interior of a barn is relatively free of partitions, parti-tions, strong internal wind pressures pres-sures develop whenever barn or haymow doors are open. These pressures can become high enough to lift off a flimsy roof deck or poorly applied roofing material When reroofing a barn with asphalt as-phalt roofing, the old surface must be reconditioned to provide a smooth, solid nailing base for the new material. In most cases, the old roofing need not be removed but can be repaired sufficiently to serve as a deck. Loose and warped wood shingles should be nailed firmly in place and missing shingles should be replaced. To increase the smoothness of the surface, wood "feathering" strips may be nailed along the butts of the old shingles. To insure that a barn roof will give satisfactory service, recommended recom-mended application procedures should be followed. Six nails are needed for each three-tab, square butt, asphalt strip shingle. For maximum resistance to wind, each tab can be spot-:emented with quick-setting asphalt cement. Special Spe-cial interlocking shingles designed for increased wind-resistance also al-so can be used. The most serviceable kind of roll roofing for permanent farm structures is the 19-inch selvage edge type. This roll roofing is produced in 36-inch-wide sheets, Because of their flexibility, as- 1 phalt shingles are especially suited for a curved gothic barn roof. and it is applied with a 19-inch i lap, giving complete double cov- j erage. The 17-inch-wide exposed portion comes surfaced with min-eral min-eral granules. , ' Nineteen-inch selvage edge ! roofing is suitable for roofs with 1 a rise of as little as one inch per foot. Some manufacturers specify hot asphalt for bonding sheets of the roofing together at the laps Others recommend cold cement! and some make roofing suitable for either hot or cold application In both cases, all nails are con-1 cealed. |