Timing: In many climates, fall and spring are the traditional periods for comprehensive window washing. The bugs that attack windows all summer long are usually gone by autumn.
As leaves come off the trees and hit the windows, the light becomes more intense, and window dirt more visible.
After the long winter, a good spring window cleaning can erase the effects of mud, snow and frost.
In arid, sunny climates windows often become dusty, and can benefit from a thorough cleaning.
Windows: Double-hung windows are two side-by-side window panels. The two panes slide vertically past each other.
True divided light windows are windows in which multiple individual panes of glass are assembled using dividers.
Simulated divided light windows have dividers affixed to the inside and outside of a panel of insulating glass to simulate the look of true divided light. These windows use gray foam spacers between the exterior and interior dividers to enhance the authentic look.
A single light window has no dividers.
Height considerations: Knowing the number of stories a house has helps your service professional give you a more accurate estimate and also helps ensure that the right tools (such as ladders and safety belts) are brought to the job.
Other suggestions: Before the experts arrive, make a careful assessment of windows that may need special attention such as hard-to-reach windows and any that have previously been coated with film to retard ultra violet rays.
In hard water regions, ground floor or basement windows may develop stains from nearby sprinkler systems and should be cleaned along with more visible windows.
Remove any breakable objects from in and around windows, especially where a ladder might be needed. Drop cloths should always be used to absorb dirty water from windows or skylights or cleaning solutions that can stain floors or walls.
Many professional window washers will also clean skylights, glass shower stalls, mirrors and lighting fixtures including delicate chandeliers.