Soil suspension

What is actually happening

This is the part of the IICRC S100 sequence where the actual cleaning happens, and it sits between dry soil removal and extraction. It is worth understanding because it is the honest basis for comparing any two methods. A low-moisture system running at ambient temperature has turned the heat dial down, so it compensates with aggressive mechanical agitation and specialised chemistry. That is a coherent design, not a defect. What it is not is a free upgrade — it is a different set of positions on the same four dials. Suspension is also not removal. A carpet can be perfectly well suspended and still have most of the soil dry back into the fibre if the extraction that follows is weak.

How you prevent it

Ask a company where it sits on each of the four. A business that has thought about its own method can answer without pausing; one that cannot has not decided, which means the decision gets made differently on every job.

Suspension is the stage where soil is broken loose from the fibre and held in the water so it can be carried away. It is governed by four variables that trade against one another — chemical action, heat, agitation and time. Lower one and something else has to carry more of the load.