Q:

My 1973 house in British Columbia has aluminum siding. In the spring, I want to change the color from gray and white to a brownish taupe color. Do you have any recommendations for preparation of the surface and best type of paint to use?

Don Martens, Williams Lake, None

A:

Brian J. Doherty, a painting contractor in Richmond, Virginia, replies: Let’s start off by not dwelling too long on the need to paint a miracle product that is never supposed to need painting. But if all you’re trying to do is change the color, the procedure should be fairly simple.

First, the surface should be thoroughly cleaned. You can scrub the siding by hand, but a pressure washer (rentable around here for $40 to $75 a day) will be quicker and easier. With either method, wash the siding with a good strong detergent mixture. When pressure-washing, I use a mixture of water, TSP (trisodium phosphate) and, if there’s an appreciable amount of mold and mildew on the siding, a little bleach. There are probably other formulas out there, but  I’ve been using variations of this formula successfully for years. Whatever you use, finish the washing process by rinsing the siding completely.

After the siding is dry, you may notice a chalky residue when you rub your fingers against the siding. That is to be expected. Rewashing will not get rid of the chalking. It may seem strange, but at this point, I proceed directly to painting two coats of high-quality latex paint without priming.

If you do have a lot of chalking on the siding, I highly recommend mixing a paint additive such as Emulsa-Bond (The Flood Co.; 800-356-6346) to the first coat of paint. These additives greatly enhance the paint’s ability to stick to the surface. The second coat of paint should be applied at full strength.

I recommend using latex instead of oil-based paint for aluminum siding because aluminum siding is flexible, expanding and contracting with atmospheric changes. Oil-based paints, on the other hand, are not flexible, and you’d likely end up with a house covered with cracked and peeling paint. Then someone would invariably suggest re-siding.