The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California

First Aid For The Ailing Houses

Detailed information on the laying of new shingles over old can be obtained from the dealers or the makers of asbestos and asphalt shingles, of dipped-wood shingles, and from the National Lumber Manufacturers Association, Washington, P.C., and the Red Cedar Shingle Bureau, Chicago, Illinois. Should dry rot have appeared in the old roof, the shingles affected need not be replaced unless their strength is greatly impaired. As rotting can occur only in the presence of moisture, it will cease as the old shingles dry out under the protecion of the new roof.

finish tor Wood Shingles In a storm, rain blows under roof shingles, and there will be rotting if it cannot dry out. Drying is quickest with unfinished shingles; but with no protection, the natural oils dry out and the shingles are likely to curl and split. For long service, roof shingles should be treated with a preservative. This penetrates the fibers, but does not greatly check the drying out of moisture. Paint, on the other hand, closes the pores, drying is retarded, and rotting is likely to occur. Paint can be used on side-wall shingles, for on a vertical surface, drainage is so complete that water does not penetrate beneath. For roof shingles, stain or oil should be used.

Unfinished and dried-out shingles can be revived by a liberal brushing of Unseed oil, although with no lasting effect. Stain and paint are best applied to shingles before laying by dipping them. As both sides will then be covered, there will be protection against moisture that later may enter beneath.

Prepared Roofing After some years of exposure, asphalt shingles and roll roofing will become brittle through drying. The dried-out oils can be renewed by brushing with a compound made for the purpose and on general sale.

Heavyweight prepared shingles will not be disturbed by heavy winds, while lightweight shingles will be lifted and will flutter. Should this continue, tearing will follow. The shingles can be secured to the roof by applying a small dab of roofing cement with a putty knife under the free ends. This is best done on a hot day when the cement will be soft and sticking will be quick. Once the shingles are well stuck, they will remain so.

Home owners might well consider investing in prepared shingles such as Seal-O-Matic, developed by Johns-Manville. Along the under side of each shingle, at the butt edge, is a strip of adhesive. After application, the heat of the sun on the roof activates the adhesive, and seals the shingle edge against the next lowest shingle, making it impossible to be lifted by even tornado-strength winds. Such shingles seal the whole roof so thoroughly against leaking that there are authenticated records of houses torn loose from foundations by tornadoes and hurricanes, but with shingled roofs still intact.