The Crawlspace Entry Hazard Check SOP

Purpose

This procedure screens a crawlspace before anyone goes under, so the space's hazards are found from the access door rather than 20 feet in, on your belly, in the dark. The things that hurt techs under houses are predictable: standing water touching wiring, a snake or a widow by the access, droppings, a bad atmosphere near a gas appliance or a sewer leak, and nobody knowing you are down there. Without a fixed screen, techs go in because the job is in there, and they find out about the water when their knee lands in it.

Scope

Covers: any entry beyond arm's reach into a residential crawlspace by any trade.

Does not cover: cleanup of droppings (The Rodent-Contaminated Work Area SOP), dead animals (Dead Animals in Walls, Ducts and Crawlspaces), or permit-required confined space entry. A crawlspace can meet OSHA's definition of a confined space (big enough to enter, limited entry and exit, not designed for continuous occupancy) under 29 CFR 1926 Subpart AA for construction work or 29 CFR 1910.146 in general industry, and it becomes permit-required when it holds a hazardous atmosphere or another serious hazard. This SOP is the screen; when it finds an atmosphere that ventilation does not clear, it stops and the space is not entered under it. Body position and strain under a house belong to the Wellbeing shelf.

Roles and responsibilities

Procedure

Step 1. Review the job before arrival. The office reads the customer history for prior notes on water, pests, wiring or gas appliances under the house, and records whether a second person will be on site. Acceptance: the work order states "crawlspace entry" and names either an attendant or the office as the check-in. Wrong looks like a tech discovering on site that the job is under the house with no check-in arranged. Stop rule: no check-in available means the office becomes the check-in by phone before step 9, or the entry is rescheduled. Hazard: none at this step; it is done at a desk.

Step 2. Open the access and light and look, body outside. Open the door or hatch with a tool or gloved hand, standing to the side, and sweep a strong light slowly over the floor, the sill plate, piers, joists, ductwork and the inside of the door frame. Acceptance: you can see the whole route to the work, or you know which part you cannot see. Wrong looks like a route that disappears behind ductwork. Stop rule: an unseen section is checked again from a closer point before you commit to it. Hazard: snakes and spiders rest in the shade of the access itself, so lift the door toward you only after lighting under its edge, with gloves on.

Step 3. Check for water and electricity together. Look for standing water, wet soil, a sump pit, and every electrical item: receptacles, extension cords, junction boxes, sump pump cords, lighting, equipment wiring. Acceptance: no standing water within reach of any cord, receptacle, box or equipment, and no cord lying in or across wet ground. Wrong looks like water and wiring meeting anywhere on or near the route. Stop rule: if water and wiring meet, nobody enters. Power to every circuit serving the crawlspace is turned off at the panel and proved dead by a qualified person (29 CFR 1910.332 and 1910.399 define who), with a meter proved on a known live source before and after (NFPA 70E-2021, 120.5; work practices at 29 CFR 1910.333(b)(2)). If proving dead requires reaching into the water, the entry waits for an electrician. Hazard: shock through wet soil can reach someone who never touches the wiring.

Step 4. Check for animals, droppings and nests. With the light, look for snakes, widow webs, wasp nests at vents, rodent droppings, raccoon latrines and animal smell. Acceptance: no live animal, no latrine, and droppings at or below the Light class of the rodent SOP. Wrong looks like a snake on the route, a latrine, or droppings beyond Light. Stop rule: a snake, wasp nest or latrine means no entry and the office calls removal; droppings beyond Light route to the rodent SOP before entry. Hazard: a disturbed nest or snake at the access is a bite or sting at face height, so back away to well beyond the animal's length before deciding.

Step 5. Check the atmosphere. Note any gas appliance, sewer line or chemical storage under the house. Hold a 4-gas monitor at the access, at the height your face will be, for 2 minutes, then clip it in your breathing zone for the whole entry. Shop alarm defaults, matching common factory settings: oxygen below 19.5 or above 23.5 percent, 10 percent of the lower explosive limit, 35 ppm carbon monoxide, 10 ppm hydrogen sulfide. Acceptance: no alarm over the 2 minutes. Wrong looks like any alarm, or the smell of gas, sewage or solvent. Stop rule: on a gas odor, leave, operate no switches, and call the gas utility from outside; on any other alarm, ventilate and re-test, and if it does not clear, the space is not entered under this SOP. Hazard: propane is heavier than air and pools at crawlspace floor level, and smell is never an all-clear.

Step 6. Check clearance and the physical route. Measure the lowest clearance on the route from soil to the bottom of joists or ducts. Shop default: 18 in or more. Look for nails through the subfloor, broken glass, sharp debris, sagging insulation and pipe wrapped in old insulation. Acceptance: 18 in or more along the route, and the route avoids wrapped pipe. Wrong looks like a pinch point under a duct or beam. Stop rule: under 18 in, find another route or reschedule with the obstruction addressed; never wedge through. Hazard: old pipe and duct wrap may contain asbestos and fibers release when crushed or torn, so the route does not brush, kneel on or crawl under it.

Step 7. Plan and clear the exit. Prop the access door open with something that cannot fall shut, keep tools, hoses and cords out of the opening, note any second exit, and stage tools at the access so you are not crawling out to fetch them. Acceptance: the access is open and clear, and the work point is no more than 30 ft from it, a shop default. Wrong looks like a hose run through the hatch or a work point deeper than 30 ft. Stop rule: beyond 30 ft requires an attendant at the access, not an office check-in. Hazard: a door that swings shut in a breeze traps you in the dark with your light as the only light.

Step 8. Dress for it. Coveralls, gloves, knee pads, bump cap, eye protection, a primary light, a backup light, and your phone in a chest pocket where you can reach it lying down. Add a respirator only under the shop's written program per 29 CFR 1910.134, where step 4 or 6 calls for one. Acceptance: two working lights and a charged phone on you. Wrong looks like one flashlight with a weak battery. Stop rule: no backup light, no entry. Hazard: coveralls in a hot crawlspace, or any respirator, raise heat load quickly, so in either case limit spells to 30 minutes and come out to cool off.

Step 9. Set the check-in and enter. Tell the attendant or the office your entry time and expected-out time, and check in every 15 minutes by voice or text. Acceptance: the first check-in at 15 minutes is answered. Wrong looks like a missed check-in. Stop rule: a missed check-in gets a call; no answer within 2 minutes, the attendant goes to the access and calls out; no response, the attendant calls 911 and does not go in, because an untrained rescuer entering after a collapsed worker is how a crawlspace takes two people. Hazard: the atmosphere can change during the work, so a monitor alarm at any point means exit first and think later.

Step 10. Exit, restore and close out. Crawl out, take the monitor and tools, close the access. Restore any circuit turned off at step 3 only after the space is empty and the access closed, standing to the side of the panel as the breaker closes, then confirm any sump pump on that circuit starts and pumps. Acceptance: everyone out, circuits restored, sump running if present, and the office told you are out. Wrong looks like a sump that does not restart. Stop rule: a sump that does not run after restore is reported to the customer before you leave, because the water comes back.

The record this produces

The job note records: findings at steps 3 to 6 (water, wiring, animals, monitor readings, clearance), any stop and who it went to, entry and exit times, every check-in time, and circuits turned off and restored. The office reads it to schedule follow-up; the next tech reads it before going under that house; the owner reads the check-in times to see whether the 15-minute rule is real.

Worked pass: a supply line leak under a house in March

A plumber is sent to a leaking supply line under a pier-and-beam house in central North Carolina after two days of heavy rain. No second person; the office is the check-in.

Step 1. Work order notes "crawlspace entry, office check-in." History shows a sump pump installed two years ago.

Step 2. Access lit from outside. Whole route visible to the leak, about 20 ft in.

Step 3. Fails. The light shows this:

  joists
  ==================================================
  |pier|      receptacle on joist          |pier|
  |    |          o---cord-----+           |    |
  |    |                       |           |    |
 _|____|______________________ | __________|____|___
  access -> route (dry)       \~~~ water ~~~/ sump
  (door)       20 ft to leak   \__ 2 in ___/  pit,
                               low point      pump off

The sump pump has stopped, about 2 in of water sits in the low point, and the pump's cord runs from a receptacle on a joist down through the water to the pit. The route to the leak is dry, but water and wiring meet 6 ft from it. Nobody enters. Proving the receptacle dead means reaching it across the water, so the office books an electrician for the afternoon and tells the customer the leak waits until then. The plumber shuts the main water valve at the street so the leak stops feeding the crawlspace.

Electrician, 2:40 pm. Identifies and locks out the crawlspace circuit, proves the receptacle dead from a dry approach with a meter checked on a known live source before and after, and replaces the failed pump. The pit is pumped down to below the pit rim.

Step 3, re-run at 3:30. No standing water touching any wiring. Passes.

Step 4. No animals, a few scattered droppings near the access, under Light. Passes.

Step 5. Gas water heater in the crawlspace. Monitor at the access 2 minutes: oxygen 20.9 percent, 0 percent LEL, 0 ppm CO, 0 ppm H2S. Passes.

Step 6. Lowest clearance on the route 21 in, under a duct trunk. 21 minus 18 leaves 3 in of margin. Passes.

Step 7. Door propped with a block. Work point 20 ft in, under the 30 ft limit. Passes.

Steps 8 and 9. Full kit, two lights, no respirator, and a cool March crawlspace, so the 30-minute spell limit does not apply. Office told: in at 3:42, expected out 4:30. Check-ins answered at 3:57, 4:12 and 4:27.

Step 10. Out at 4:31, one minute past the stated expected-out time, office told. The electrician's circuit stayed on, so nothing to restore; the new sump pump cycles once as the plumber watches. The street valve is reopened and the repaired line holds.

References

• OSHA, 29 CFR 1926 Subpart AA Confined Spaces in Construction; 29 CFR 1910.146 Permit-Required Confined Spaces
• OSHA, 29 CFR 1910.333 Selection and Use of Work Practices; NFPA 70E-2021, 120.5 (verifying absence of voltage)
• OSHA, 29 CFR 1910.134 Respiratory Protection
• See related: The Rodent-Contaminated Work Area SOP
• See related: Snakes Under Houses and Inside Equipment