Surfaces and textiles

The coating needs something to bond to. That is the whole of the practical theory: a clean, dry, reasonably stable surface holds a treatment for its full life, and a dusty, greasy, damp or crumbling one does not. Most disappointing results in the field are a preparation problem rather than a product problem.

Surfaces on the current reference list: ceramic tile, glass, acrylic, galvanised steel, unpainted cement, vinyl flooring, skirting boards, painted walls in kitchens, and cracks and crevices near food areas. These are the surfaces the reference testing covers, and the list is being verified line by line before it is published beyond the preview.

Smooth and sealed surfaces are the straightforward case: tile, glass, acrylic, sealed vinyl, powder-coated and galvanised metal, gloss and satin paint. Clean, dry, treat, done. These hold a treatment most predictably and are where a coverage figure will be most reliable.

Porous and unsealed surfaces are the ones to test: raw and oiled wood, untreated stone, old brick, unpainted cement, lime plaster, terracotta. They absorb, which can shorten the working life on the surface and can also change the appearance of the material. Treat a hidden area, let it dry fully, and look at it in daylight before committing to a run.

Surfaces to leave alone: food contact surfaces, hand contact points such as grab poles, handrails and controls, safety-critical components and webbing, certified protective equipment, display glazing and screens, anything a child or an animal puts in its mouth, and any surface the label does not cover. When in doubt the label decides, not this article.

Textiles: cotton, polyester, outdoor gear, upholstery and sofas. Work the seams and tucks, which is where insects sit and where a fast pass usually misses. Test an inconspicuous area first for colour and finish, and let the item dry fully before it is used. A treatment does not survive a wash cycle, so any washed item is retreated at the next service.

Preparation, in order, whatever the surface. Remove dust and grease with an appropriate cleaner. Rinse if the cleaner leaves a residue, because a detergent film is a barrier. Let the surface dry completely. Then treat. Skipping the drying step is the most common cause of a patchy result.

Things that shorten the life of a treatment on any surface: frequent wet cleaning with detergent or solvent, abrasion from handling, direct rain on an exposed outdoor surface, and condensation. None of these are faults; they are the reason the reapplication interval exists.