Pre-Wet and Plant Protection Before a House Wash

Purpose

Sodium hypochlorite kills the algae on siding by the same mechanism it kills a boxwood: it breaks down organic tissue on contact. A wash that gets the mix and the technique right on the wall still costs the shop a landscaping claim, a dead pool pump, or a customer's irrigation controller stuck mid-cycle if nobody protected what sits inside the drift radius before the chemical left the tank. This standard fixes what gets soaked, what gets covered, and what gets shut off before the wash starts, so protection does not depend on whoever happens to notice the pool equipment pad on the way past.

Scope

Covers everything inside the wash's overspray and runoff radius that is not the siding itself: plant beds and turf near the drip line, pool circulation equipment, irrigation heads and controllers, exterior fixtures, and parked vehicles. Runs before any chemical leaves the tank and closes with a signed handoff to the Soft Wash House Procedure standard. Does not cover the wash application itself or the rinse and restore-verification, both owned by their own standards; this SOP produces the isolation log those standards close out.

Roles and the handoff between them

Before anything gets covered or shut off

Not every plant tolerates the same exposure, and the standard soak is not a substitute for physical covering on the sensitive ones. Boxwood, certain hydrangea varieties, and Japanese maple are commonly reported as chlorine-sensitive at concentrations this trade routinely runs; treat anything the estimator flagged as sensitive, or anything already stressed by drought or root disease, with full poly covering rather than pre-wet alone, and route around it if covering it fully is not practical on the visit.

A pool equipment pad is a wet electrical environment. Before touching a breaker or switch at the pad, confirm GFCI protection is intact and never operate a control with wet hands or while standing in standing water at the pad. And if that does not hold, meaning the pad shows damaged insulation, a tripped breaker that will not reset, or any sign of water intrusion at the panel, do not work the pad yourself; isolate the area and route the pump shutdown to a licensed pool technician before the wash proceeds near that equipment.

The procedure

1. Walk the sensitive-zone list against what is actually on site. Confirm every item the estimator flagged, bed locations, pool, irrigation zones, fixtures, is where the ticket says it is, and note anything present that was not flagged. Acceptance: every listed item located and visually confirmed, with additions logged. Wrong looks like soaking the one bed everyone can see and missing the side-yard bed the ticket also names. Stop rule: an item that cannot be located, or a new sensitive item spotted on site, gets added to the ticket before protection work starts, not discovered mid-wash.

2. Soak plant beds and turf inside the wash radius with plain water. Saturate the soil and wet the foliage thoroughly, not a surface mist that beads and rolls off. Pre-wetting works by diluting any chemical that reaches the plant and by giving the root zone a buffer before contact; a misted leaf gets none of that protection. Check the soak by pressing two fingers into the mulch or soil at the drip line: if it is still dry an inch down, give it more water before moving on rather than trusting how wet the surface looks. Acceptance: soil visibly saturated below the surface and foliage wet through, not beaded. Wrong looks like a quick pass with the hose that wets only the top inch of soil and reads as done from a glance. Stop rule: any plant already showing drought stress or root disease is not included in the standard soak-and-tolerate approach, it gets full covering or gets routed around instead.

3. Cover chemical-sensitive plants and beds too close to reliably keep overspray off. Use poly sheeting, not cloth or tarp fabric that can still pass mist through, secured at the base against the soil so wind cannot lift it. Acceptance: full coverage, base sealed, secure against a moderate gust. Wrong looks like sheeting draped loosely over a shrub that a gust lifts mid-wash. Stop rule: if wind is already strong enough during setup to lift loose sheeting, that is also the signal to hold the wash start until wind drops, not just a sheeting problem to solve harder.

4. Isolate pool circulation if a pool sits inside the drift radius. Shut the pump off at the equipment pad, confirm it is actually silent, not just switched off with a smart controller that can restart it, tag it "off for wash, do not restart," and cover the skimmer intakes. Acceptance: pump confirmed silent, tag placed, skimmers covered. Wrong looks like a breaker flipped while the pump is on a scheduled override that restarts it twenty minutes later. Stop rule: if the pump cannot be positively confirmed off, given a smart controller with no visible manual disconnect, do not proceed near the pool until it is isolated properly; route to a licensed pool technician rather than guessing at the interface.

5. Isolate the irrigation controller if a zone sits inside the wash radius. Suspend or disable the affected zone's schedule on the controller itself, not just a mental note of the run time. Acceptance: schedule suspended and confirmed on the controller display. Wrong looks like "it only runs at 6am, we'll be done by ten" with the schedule left active, then a rain-sensor reset or a manual override fires it mid-wash. Stop rule: if the controller is unfamiliar or locked and cannot be confirmed disabled, physically cap or divert the affected head instead of trusting the schedule.

6. Cover or relocate anything else the chemical will damage. Parked vehicles left to dry with overspray etch clear coat, since the SH and any dissolved minerals in the rinse water concentrate as the droplets evaporate under sun, leaving a mark that a plain water rinse could have prevented; fabric light-fixture shades and unsealed natural stone or dark-stained hardscape can bleach or spot the same way. Acceptance: each item covered, moved, or logged as flagged. Wrong looks like a car left in the driveway "just for twenty minutes," which is long enough for overspray to dry under direct sun. Stop rule: a vehicle that cannot be moved, no owner present with keys, means that elevation gets rescheduled to last and the customer is asked to move it, not sprayed around on a guess.

7. Set up any ladder access to standard before climbing for a fixture or gutter check. Confirm a 4-to-1 pitch, extension of at least 3 feet above the landing per 29 CFR 1910.23, and solid footing before ascending. Acceptance: pitch, extension, and footing all confirmed. Wrong looks like leaning the ladder against the gutter for a "quick" reach. Stop rule: no confirmed stable footing means no climb, use an extension pole instead.

8. Sign off the handoff to the wash standard. Confirm every item on the sensitive-zone list is checked complete on the ticket before chemical is released to the mix station. Acceptance: full checklist signed. Wrong looks like a verbal "we're good" with items still open on the ticket. Stop rule: chemical does not leave the tank until this sign-off exists.

The record this produces

A protection worksheet on the ticket:

• Sensitive-zone list: every item flagged at booking, with anything added on site.
• Plant treatment log: which beds were soaked, which were fully covered, and why.
• Isolation log: pool pump and irrigation controller status, tag placement, and the time each was shut off, since an irrigation schedule missed by the tag but still active elsewhere on the property is a timing problem, not a tagging one.
• Coverage log: vehicles, fixtures, and hardscape covered or relocated.
• Sign-off: the completed checklist that releases the wash SOP to begin.

The isolation log is what the wash standard's own restore step reads from; an isolation nobody logged here is a pump nobody knows to turn back on.

One run of this procedure, filled in

Single-story house with an in-ground pool along the wash-facing elevation, moderate wind forecast for later in the day.

• Step 1: sensitive-zone list confirmed against the ticket; an unflagged hydrangea bed near the pool equipment pad was found and added.
• Step 2: turf and the front foundation bed soaked thoroughly.
• Step 3: the newly added hydrangea bed covered in poly sheeting and sealed at the base, since hydrangea is on the sensitive list.
• Step 4: this step failed on first attempt. The pool pump appeared off at a wall switch, but a smart controller override brought it back on within a minute, confirmed by sound. Stop rule taken: the crew did not proceed near the pool, called the customer's pool service contact, and had the pump isolated at the equipment breaker with a physical lockout rather than the wall switch before continuing.
• Step 5: irrigation controller's pool-side zone suspended and confirmed on the display.
• Step 6: no vehicles or additional fixtures in the radius.
• Step 7: no ladder access needed on this visit.
• Step 8: full checklist signed off, chemical released to the mix station.

The pool pump near-miss is the reason step 4's acceptance condition is a confirmed silence, not a switch position: a switch can lie, a controller cannot be argued with after the fact.

References

• 29 CFR 1910.23, portable ladder requirements, for the exception cases where fixture or gutter access needs a ladder.
• See related: Soft Wash House Procedure Standard, Rinse Sequence and Final Inspection Standard.