If you're washing exterior cladding, weatherboards, fences, or driveways for a living, you need something that cuts through grime and mould without eating through your equipment or the surface you're cleaning. Trade Chem's House Wash is built for exactly that.
What it's for
House Wash is a biodegradable exterior house wash detergent, formulated to lift dirt, grease, oil, soiling, mould, mildew, and general exterior grime ahead of rinsing or pressure washing. It's alkaline (pH 11.0), which gives it the cutting power against built-up exterior soiling, and it's manufactured to be safe on all painted surfaces without damaging surrounding plants when used as directed.
A gentler alternative to bleach-based soft wash
Most soft wash solutions rely on sodium hypochlorite (bleach) to kill mould and algae. It works, but it comes with real downsides, it can react with organic pigments in certain paint colours and cause staining, and plenty of homeowners are understandably wary of having a bleach solution sprayed across their house.
House Wash contains no bleach. It's a straight detergent clean, using surfactants and alkalinity to lift dirt, grease, and grime rather than chemically bleaching organic growth. That makes it a softer-touch option for customers who want their exterior cleaned without bleach on their property, though it's worth being upfront that it's cleaning and lifting soiling rather than killing mould and algae at the root the way a bleach-based treatment does.
How to use it
Whole-house cleaning (primary method): Spray the entire exterior top to bottom, leave for 10 minutes to let it break down the grime, then pressure hose off.
Dilution: up to 1:40 (product:water) for general cleaning. For heavier dirt or soiling, use a stronger (lower) dilution ratio, less water, more concentrate, the worse the buildup.
Spot treatment for stubborn areas: For heavily soiled patches, mould buildup, or textured surfaces like weatherboard grain, mix House Wash into a bucket at your working dilution and apply with a brush or sponge for added agitation. This works the solution into the surface more than spray alone can on rough or heavily soiled spots. Wear gloves for this method, direct hand contact time is much higher than with spray-and-rinse, and at this pH sustained skin contact is where irritation risk becomes relevant.
House Wash also contains corrosion inhibitors and helps prevent the regrowth of fungi and moss after cleaning, useful if you're offering repeat exterior cleaning contracts rather than one-off jobs.
Handling it safely
House Wash carries a WARNING signal word, a moderate-hazard product, not a severe one. Two things worth knowing:
- It causes serious eye irritation, worth wearing eye protection when mixing concentrate or spraying, especially in wind or with pressure equipment.
- It's toxic to aquatic life with long-lasting effects. Don't let runoff go straight into stormwater drains or waterways, standard practice for any exterior wash contractor already.
Shipping
House Wash ships nationwide in both 5L and 20L sizes, wherever you're based in New Zealand.