A few days ago a friend contacted me and explained that she and her husband are going to put their house on the market soon and wanted to know if it was OK for us to wash her exterior siding now. My recommendation is to hold off for the time being. Even if the air temperature warms up into the 30’s or 40’s for one or two days, the core temperature is much colder since it is been at or around freezing for several weeks now.
We do not want to take the chance of flash freezing of water on the house surface or the surrounding shrubs & trees, ground, or walkway. Additionally, chemicals used for cleaning simply do not work as well when it’s very cold outside. It’s early February right now and it may not be warm enough for another six weeks here in the mid Atlantic region. The exception would be if we get a warm spell of perhaps 55° and above for at least two to three days.
Even though we frequently use hot water washing, the likelihood of compromising safety, in addition to sub optimal chemical performance, would lead us to recommend waiting until it warms up a bit. Of course your situation can be different and there might be an urgent need or emergency. Please feel free to contact us if you have cleaning that needs special attention right away.