Q The white cedar shingles on the roof of my two-year-old house have weathered to a nice shade of gray, except for those in the rain-runoff area of the brick chimney. They are a streaky white color. The chimney is flashed with lead. Is the lead causing the streaking? If so, what can I do? Donald G. O'Brien Rye Beach, N.H. I don't believe the lead could be the cause of the streaking. To check it, see if the lead itself is turning white. Normally lead turns a dark gray.
The cause could be the accumulation of salt on the face of the chimney because of your proximity to the ocean. When the salt water runs off, the surface may eventually turn white. Another cause could be the efflorescence of the masonry chimney itself. This can be stopped by applying a clear, penetrating masonry sealer.
Q Some of the double-hung windows in my 25-year-old house slide on aluminum ways on each side and there is no way to keep the upper sash from sliding down. Any solution? Robert A. Bliss Janesville, Wis.
These windows can be difficult to repair as they are almost impossible to disassemble.
The first thing that comes to mind is the insertion of a strip of brass weatherstripping into the tracks to provide some friction. Another solution might be the installation of small slide bolts on the window frame with holes drilled into the jamb at various points.
It seems to me that the weatherstripping, either brass or nylon, would be better if you can get it to fit. Besides keeping the top window in place, it would help reduce air leakage as well.
If you have a question about improving or maintaining your home, send it to the real estate editor, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115.