Printed in the Idaho Press-Tribune October 10, 2009

To most people, the crisp days of fall means their outside home improvement projects must end. If you wanted to paint your exterior, and it still hasn't happened, it is not necessarily too late.

In today's world of advanced latex paints (latex meaning water based) a natural step for the demanding consumer is low temperature paint. Just about every major paint brand has a low temp line of exterior paint. Low temp paints are every bit as durable and long lasting as the standard exterior paints, sometimes even more so.

The idea behind low temp paint is how well it sticks to cooler surfaces (adhesion), and how fast the moisture can evaporate from it (drying time). These things are critical this time of year when temperatures can drop suddenly as the sun sets, especially when the time changes.

Every low temp paint has its own specifications, but generally it is designed for use in the mid 30 degree range. The low temp paint that I prefer (Kwals) is rated to 34 degrees. The thing you must remember, that is 34 degrees surface temperature, not air temperature.

As you all know, the sun beaming on a surface can really heat it up. This is what they mean by surface temperature. No matter what the daytime air temperature might be, the surface temperature must be at least the temperature listed for the paint you are using. This means also that on shady sides of your home (this is generally the north side for most of us) even if the air temperature is well above the minimum, the surface may not be warm enough without the sun.

So basically, you must use your head when painting in fall weather. The morning is generally the coolest time of the day with frost or foggy conditions. You must wait for the sun to come all the way up, burn off any fog hanging in the area, and warm the surface you intend to paint. You must also work with the sun as the day continues on, planning in advance how to move around your home to take full advantage of the warmth.

Also, pay close attention to how late in the day you paint. The paint must dry before the sun goes down and the temperature reaches freezing. A good rule of thumb is to give yourself two hours before sunset. If you have been applying the paint to a sunny surface, two hours will give you plenty of drying time.

If you do have a cold or shady side to paint, make sure you do it during the warmest part of the day. Noon or shortly after will give the paint a longer time to set up before it gets really cold. No matter what, never paint a surface that still has frost on it. This means the surface temperature has not warmed enough.

Of course, I must add to all this that I am talking about your traditional fall or winter days, cold but sunny. It is never ok to paint in the rain, snow or extreme fog. Moisture in the air does not allow the moisture in the paint to evaporate.

Well, it might take a little more time, a little more planning, but look at it this way. If you do paint your house this time of year, you can start late and quit early!