Fungus From Mulch Can Damage Vinyl Siding

Q: The vinyl siding on our house has many small black spots that we understand are caused by a fungus in mulch. How can we remove these ugly spots? -- M. Haaser

A: A great deal of research has been done on the widespread and damaging artillery fungus, which sprays spores on any nearby surface and often originates in rotting hardwood mulch. Some experts say the only practical way to remove the tar-like spots is by laborious scraping, but there have also been reports that it can be removed by some cleaners. I cannot recommend some of the cleaners used (such as oven cleaner and automotive wheel cleaner) because I think they would cause more damage.

However, a few cleaners might work and are worth a try, although any of them should be tested first in an inconspicuous place. Vigorous scrubbing will also be needed with any cleaner.

A leading possibility is Mr. Clean Magic Eraser. Another is a solution of one part chlorine bleach and 1/2 -cup TSP heavy-duty cleaner (sold at paint stores) to three parts water. Simple Green spray cleaner is a third possibility.

If you must scrape, use a single-edged razor blade or a razor-blade scraper (sold at paint stores). Small brown stains often remain after scraping; these can sometimes be removed by scrubbing with a detergent. In severe cases, priming with an oil-based primer and painting can restore the siding.

Infected mulch must be removed, of course. Penn State researchers studied 27 mulches, and concluded that the most fungus-resistant was large pine-bark chips. Cypress mulch was also rated highly. Marble chips and other inorganic mulches work well.

Unfortunately, most insurance companies no longer cover mold damage, but you should contact your insurance agent to make sure.

Q: I need a new storm door, but I can't find one with lightweight plastic instead of glass. This is important because I can't lift a heavy glass pane for storage in the summer when I will want an insect screen. -- J. Caputo

A: Many storm doors don't require removing the glass. They have a self-storing glass sash and screen. To switch from all-glass to screen, one of two glass panels slides out of the way and exposes the screen. You can see doors of this type at most home centers, including Home Depot, where sample doors are displayed. Installation is also available through most home centers.

Q: I have a deck with composite decking. The deck boards are so close together that water collects during rains and takes a long time to drain away. Can I safely drill small holes in this material to provide some drainage? -- D. Penne

A: The best bet is to drill the drainage holes at the junction of two deck boards. Drill close to but not into supporting joists, which can be located by noting where deck screws are inserted. Just a few holes at strategic spots should provide enough drainage. I would not make the holes any larger than 1/4 -inch in diameter.

Questions and comments should be sent to Gene Austin, 1730 Blue Bell Pike, Blue Bell, Pa. 19422. Send e-mail to doit861@aol.com. Questions cannot be answered personally.