Lesson 1: Fiber Identification and the Pre-Inspection Walkthrough
Before any water touches a carpet, you must know what you're cleaning. The two broad categories are natural fibers (wool, cotton, silk, sisal) and synthetics (nylon, polyester/PET, olefin/polypropylene, triexta). Nylon is the most common residential face fiber: durable, resilient, but pH-sensitive, so keep cleaning solutions near neutral (pH 5-9). Wool is also pH-sensitive and bleaches or browns easily, so never use high-alkaline or oxidizing bleach products on it. Olefin resists water-based stains but attracts oily soil and can wick badly. Polyester is stain-resistant but oleophilic and crushes underfoot.
The burn test (a single fiber tuft held to a flame) is a field ID method: wool smells like burnt hair and self-extinguishes; nylon melts and smells like celery/plastic; olefin melts cleanly and floats in water. Always confirm with the manufacturer label or a moisture/specialty test when possible.
During pre-inspection, walk the job with the customer. Document existing damage, traffic lanes, color, and matting. Test colorfastness in a hidden spot by blotting a white towel with your cleaning agent; any color transfer means switch products or methods. Identify construction (cut pile, loop/Berber, woven) and backing, since over-wetting jute backing causes shrinkage and browning. Note pre-existing conditions in writing so the customer cannot later blame you. This inspection drives every downstream decision: chemistry, water temperature, agitation, and dry time.