Prespraying carpets tends to use less chemical, which is a cost savings. It also allows the chemical to break down and dissolve soils so that they can be more effectively removed. With more facility service providers now including carpet cleaning among their tasks, it is important to learn how to properly prespray a carpet.
 
Typically, carpets are first presprayed and then rinsed clean using a hot-water extractor. There are several reasons for this.
 
Pre-spraying also allows the chemical to dwell on the carpet, breaking down and dissolving soils so that they can be more effectively removed by the extractor.
 
"Presprays are typically comprised of surfactants and solvents," says Doyle Bloss, a leader in the carpet cleaning industry and marketing director for U.S. Products.  "[Further] more advanced formulations contain an integrated blend of specialized polymers that together get carpets cleaned faster, resist future soiling, and keep carpets cleaner longer."
 
As to properly using presprays, Bloss has the following advice:
 
Select the Right Products. Select a prespray based on carpet soiling conditions and the type of carpet; pre-sprays are formulated for either lighter or heavier soiling, different types of conditions (a restaurant vs. an office, for example), and to work more specifically on different types of carpet (wool vs. nylon, etc.).
 
Apply Properly. Apply the prespray using an in-line injection sprayer, pump-up sprayer, or electric/battery-powered sprayer.
 
Observe the Proper Dwell Time. Prespraying before cleaning an area allows the chemicals to dwell. However, be sure not to spray so far in advance that the chemical has time to dry. If it does dry, do not reapply the chemical; instead, use the extractor wand to re-wet the area.
 
Provide Agitation. Agitating presprayed areas can help cleaning chemicals work more effectively; consider using a carpet grooming rake or cylindrical brush machine for this task.
 
Use Hot-Water Extraction. Extract the carpet using a hot-water carpet extractor; consider adding a compatible detergent or neutralizing rinse to the rinse water to help insure proper removal of soils and chemical residue from the carpet.
 
"Presprays are the work horse of carpet cleaning," says Bloss. "Used properly, they dislodge, emulsify, and suspend carpet soils, leaving carpets clean and healthy after hot-water extraction."