5 Best Chemical For Pressure Washing House | Sticks Where Sprayed

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The gallon of concentrate that powers away grime in minutes without running back to the store.

This is the jug you reach for when you want the most cleaning power per dollar. It is a 128 oz concentrate (a full gallon), and owners mention it is “effective at 5:1 dilution with pump sprayer for pre-wash; removes mold/mildew.” You simply put your pressure washer’s detergent tube into the jug, spray it on, let the formula work for a few minutes, and rinse with a higher-pressure nozzle. The EPA-registered status (meaning the U.S. Environmental Protection Agency has approved its claims) backs up the mold and mildew removal without any guesswork.

Unlike the Rust-Oleum Jomax which weighs 3.78 pounds, this 5.7-pound jug holds 128 oz, while the AL-NEW hose-end sprayers hold 64 oz. Reviewers specifically note this concentrate works perfectly with pressure washer attachments, so you skip the extra hose-end plumbing. One buyer did caution that you should avoid adding laundry bleach because it can damage window seals and void warranties, so stick to the product as-is.

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The industrial-grade concentrate that stretches to 20 gallons and covers half a roof.

Zep calls this “Construction Grade,” and the yield backs that up — each gallon makes enough to cover 5,000 square feet when diluted. That is roughly the entire siding on a 2,500-square-foot home with a two-car garage. Reviewers who used it followed the heavy-buildup instructions: they mixed the concentrate, sprayed it on their vinyl siding, brushed it in, and rinsed with a hose, noting that “algae, mold, and dirt removed completely” and the job saved hundreds of dollars compared to hiring a pro.

Where this pulls ahead of the W M BARR is application flexibility. Zep explicitly lists compatibility with vinyl, aluminum, wood, hard coat stucco, brick, and cement (Hardie Plank siding), so it is not a one-surface wonder. The case of two jugs means you can keep one in the sprayer and one as backup for heavy stains. It is heavier (8 Pounds for the case) but that weight buys you double the potential working solution — compare that to the Southeast Softwash Southern Twang below, which is a surfactant additive rather than a standalone cleaner.

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The bleach-free formula you can spray around pets and plants without panic.

Jomax is the only product in this list that skips bleach entirely and still promises to remove stains on siding, fences, decks, patios, roofs, and more. You mix it 1:4 (one part cleaner to four parts water) to make up to 5 gallons — about 1,500 square feet of coverage. The manufacturer says no scrubbing or rinsing is required; you apply it with a pump-up garden sprayer and let the natural weather conditions do the work over 1-2 days. Buyers have used it for years on manufactured homes in different states and report it works great on shower grout and patio furniture too.

The catch, and it is a real one: Jomax is slow. Customers note results appear in “1-2 days, lasts a season,” but it is not an instant whitener. Compared to the AL-NEW Outdoor Cleaner which requires light scrubbing, Jomax at least does not demand physical effort — you just need patience. At 3.78 pounds it is the lightest jug here (the W M BARR weighs 5.7 pounds), so it handles easily in a garden sprayer, but you give up the coverage density of the Zep or W M BARR concentrates.

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The two-pack hose-end sprayer that saves you mixing — and saves per wash.

This is the only pick that comes ready to spray: you screw the 64 oz bottle onto your garden hose, turn on the water, and the built-in nozzle dilutes the cleaner automatically. The non-bleach formula is safe for lawns, pets, and your clothes, which buyers confirm makes it a great alternative to messy bleach applications. One reviewer specifically noted it is “great for soft washing mobile home siding” and that using it saved per professional wash. It works on vinyl siding, aluminum siding, fencing, awnings, window frames, gutters, and plastic furniture.

The honest limitation: reviewers point out it “doesn’t work well without scrubbing” and that heavy green buildup may need a second pass. The pack of two bottles gave one buyer “only good for one side” of their house. Compare that to the W M BARR concentrate which holds 128 oz and can be fed directly into a pressure washer — the AL-NEW is undeniably easier to start but less economical per square foot. The weight (9.35 Pounds for the pack) is heavier than the Rust-Oleum Jomax at 3.78 Pounds, but that weight includes the sprayer mechanism.

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The professional surfactant that clings to walls and makes bleach smell like fresh apples.

Southern Twang is different from every other product on this list — it is a surfactant (a chemical that makes liquid stick to surfaces), not a standalone cleaner. You batch-mix it with chlorine, bleach, or sodium hypochlorite (about 15 gallons of water per 1 gallon of product) and run it through a downstream injector or softwash gun. What makes it unique is the cling: one reviewer noted, “It clings vertically which blows my mind!” Another professional contractor noted it “helped slow down my house wash mix considerably so the SH could work longer.” The apple scent is a bonus that masks the bleach smell, making the job more pleasant if you are sensitive to chemical odors.

If you are a DIY homeowner with a garden sprayer, this is overkill — you need a bleach source and a proper diluting system to open up its full value. But if you already use the W M BARR or Zep concentrate and want better contact time on steep gables or second-story walls, adding a splash of Southern Twang to your mix is the single upgrade that changes your results. It is the only product here where a single gallon treats roughly 15 gallons of finished mix, which is serious efficiency if you wash a lot of surface area.