How to clean out a crawl space contaminated with mold, rodents, asbestos, or sewage.

Here we discuss safety precautions and cleaning approaches for a dirty or contaminated building crawl space. We explain that first you should inspect the crawl space for visible signs of unsanitary or unhealthy contaminants.

How Clean Up the crawl space: remove asbestos, mold, rodent droppings, unsanitary soils, insulation

Cleanup methods need to include steps to prevent spreading contamination to other building areas. We include discussion of using vacuum cleaners and power washers in crawl areas. .

This article series describes the steps needed to get into, inspect, clean, and then dry out a building crawl space.

We give a step by step crawl space entry, inspection, cleanout, dryout and keep dry guide explains how to get into or inspect a crawl space even if there is no ready access, how to assess crawl space conditions, how to stop water that is entering the crawl area, how to dry out the space, how to clean up and if necessary disinfect or sanitize the crawl space, and how to keep out crawl space water and moisture in the future.

Is there asbestos insulation in the crawl space? Often we find a crawl area in which the asbestos pipe insulation is not just hanging (photo at left) but has fallen onto the crawl space floor.

[Click to enlarge any image]

Asbestos pipe or HVAC duct insulation that has been disturbed, damaged, or deteriorated, including asbestos that has fallen to the floor should be removed and cleaned up by a professional. Asbestos pipe insulation that is in good condition, that is not damaged, might be left in place or perhaps left in place and encapsulated.

Do not enter such an area without protective equipment; take care that you do not track hazardous materials out of the crawlspace and into other building areas.

Do not track asbestos debris back into other building areas.

Is there evidence of mold contamination such as areas of wood, paper, or other material covered with mold or mold-suspect material.

If the crawl area has more than 30 sq.ft. of contiguous toxic or allergenic mold it should be cleaned by a professional mold remediation company.

Beware: often the most serious mold we find in crawl spaces is not the mold you see on wood framing but rather the mold you don't see in fiberglass insulation in a damp or wet area.

See MOLD in FIBERGLASS INSULATION for details.

Watch out: If the crawl space has a large area of mold (more than 30 sq ft) or if you suspect it may be contaminated with rodent droppings, chemicals, pesticides, (or electrical hazards)

see CRAWL SPACE SAFETY ADVICE

and CRAWLSPACE MOLD ADVICE.

Do not enter such an area

without PROTECTIVE GEAR.

Cleaning Up a Crawl Space After Rats, mice & other crawl space rodents

Beware also of rodent-infested crawl areas; there may be bacterial or viral hazards from these animals, or from their urine and feces, and in some areas there may be a Hantavirus hazard.

Hantavirus pulmonary syndrome (HPS) is a deadly disease from rodents. Humans can contract the disease when they come into contact with infected rodents or their urine and droppings.

HPS was first recognized in 1993 and has since been identified throughout the United States. Although rare, HPS is potentially deadly. Rodent control in and around the home remains the primary strategy for preventing hantavirus infection. - [3] US CDC

If it is necessary to remove rodent feces or urine-stinking soil (try using a "black light" to spot urine stains) your cleaning company may decide to actually remove the top few inches of contaminated soil in the most offensive areas, followed by sanitizing, sealing, and poly vapor barriers on crawl space floors and lower walls.

See BLACK LIGHT & UV LIGHT USES

Also see LIGHT, GUIDE to FORENSIC USE for help in spotting mold or similar contaminants on building surfaces

Watch out: don't remove so much soil that footings are undermined at foundation walls or supporting columns. If necessary, bring in and compact clean fill and gravel to fill low areas.

Question: biocide is best for sanitizing crawl space dirt where there are rat droppings?

2017/11/15 ray said:

which biocide is best for sanitizing crawl space under house with rat dropings on the crawlspace (dirt)?

This question was posted originally

at DISINFECTANTS & SANITIZERS, SOURCES

Reply:

Ray,

The US CDC recommends use of a bleach solution as a disinfectant indoors when cleaning up rodent droppings. I'll quote from that information below.

According to Contec, "To date, the EPA has approved only Formaldehyde for the disinfecting of dirt and soil. However, the health risks to workers and occupants, along with the need for extensive protective measures, negate the use of Formaldehyde for remediation purposes. "

There are also proprietary disinfectants suitable for cleanup of bird, bat, and rodent droppings such as Contec's Sporocidin® that I will also give below.

The following advice on cleaning up rodent droppings is from the US CDC

First, clean up any urine and droppings

When you begin cleaning, it is important that you do not stir up dust by sweeping or vacuuming up droppings, urine, or nesting materials.

Wear rubber, latex, or vinyl gloves when cleaning urine and droppings.

Watch out: In a crawl space you need more protective gear, clothing, respirator, &c. since breathing rodent urine-infected soil dust or dropping dust is hazardous - Mod.

Spray the urine and droppings with a disinfectant or a mixture of bleach and water and let soak 5 minutes.

The recommended concentration of bleach solution is 1 part bleach to 10 parts water. When using a commercial disinfectant, following the manufacturer’s instructions on the label for dilution and disinfection time.

Use a paper towel to pick up the urine and droppings, and dispose of the waste in the garbage.

After the rodent droppings and urine have been removed, disinfect items that might have been contaminated by rodents or their urine and droppings.

Next, clean and disinfect the whole area - [see notes below about disinfecting in dirt crawl space - Mod]

Lastly, remove gloves, and thoroughly wash hands with soap and water (or use a waterless alcohol-based hand rub when soap is not available and hands are not visibly soiled). - (CDC 2017)

In a crawl area, after you've cleaned up the droppings you'll usually want to put down a 6 mil poly plastic barrier over the dirt.

\Cleaning Up Crawl Space Contaminants - Asbestos, Mold, Rat & Mouse

A reader asked if we thought he needed a professional mold remediator to clean the wet crawl space shown in this photo and also

at CRAWL SPACE DRY-OUT PROCEDURE.

[Click to enlarge any image].

Our opinion was:

If you don't find more mold than in the photos this is not a mold remediation project it's a clean and dry-out project that needs to focus on first dryout and next, preventing more water entry or moisture.

If you find 30 sq.ft. or more of contiguous moldy mateirals then I'd consider calling a professional mold remediator.

• Baker, Rex O., Gerald R. Bodman, and Robert M. Timm. RODENT-PROOF CONSTRUCTION AND EXCLUSION METHODS [PDF] (1994). The Handbook: Prevention and Control of Wildlife Damage, Internet Center for Wildlife Management, University of Nebraska, Lincoln,
  Abstract:
  The most effective means of limiting rodent damage is rodent-proof construction. New buildings should be designed and built to prevent rodent entry. Rodent-proofing is a good investment.
  
  Designing and constructing a rodent-proof building is less expensive than adding rodent-proofing later.
  
  Nevertheless, poor maintenance or management practices, such as leaving entry doors and unscreened windows open, will make the bestconstructed building susceptible to rodent entry.
  
  Techniques discussed here apply both to new construction and to the modification of existing structures.
• CRAWL SPACE SEAL & SANITIZE - Guide to Using Crawl Space Sealants & Sanitizers
• DISINFECTANTS, SANITIZERS, FUNGICIDAL-SEALANTS SOURCES - How to Buy Disinfectants, Fungicidal Sealants, Sprays, Biocides used on or in Buildings
• Contec®, "CLEANING & DISINFECTING GUIDELINES FOR BIRD, BAT, AND RODENT DROPPINGS " [PDF] Contec® Sporicidin® Contec, Inc. P.O. Box 530 Spartanburg, SC 29304 USA Tel: +1-864-503-8333 Toll Free US, Canada, PR: 1-800-289-5762 Email: info@contecinc.com
  
  Excerpt:
  
  This is a guideline for using Sporicidin® Disinfectant products in the cleaning and disinfecting of surfaces and materials contaminated with fecal matter from birds, bats and rodents.
  
  This guideline is not applicable for the remediation of dirt floors, such those found in crawlspaces or farm structures like coops and barns.
  
  Sporicidin® Disinfectant products are intended for use in this guideline for the cleaning and removal of feces, urine, and other contamination from porous and non-porous surfaces or materials, and the disinfection of hard, non-porous surfaces.
  
  To date, the EPA has approved only Formaldehyde for the disinfecting of dirt and soil. However, the health risks to workers and occupants, along with the need for extensive protective measures, negate the use of Formaldehyde for remediation purposes.
• CRAWL SPACE GROUND COVERS - inspectapedia.com/Energy/Crawl_Space_Ground_Cover.php
• CIEH, PEST CONTROL PROCEDURES IN THE HOUSING SECTOR, [PDF] (2010) Chartered Institute of Environmental Health, Website: www.cieh.org retrieved 2017/11/15, original source: http://www.cieh.org/uploadedFiles/ Core/Policy/Environmental_protection/ Pest_management/NPAP/ pest_control_procedures_in_the_ housing_sector.pdf
• DPMAC, PROTECTION FROM RODENT-BORNE DISEASES, WITH SPECIAL EMPHASIS ON OCCUPATIONAL EXPOSURE TO HANTAVIRUS [PDF] Defense Pest ManagementInformation Analysis Center Forest Glen Section Walter Reed Army Medical Center Washington, DC 20307-5001 (2013) retrieved 2017/11/15 original source: https://www.acq.osd.mil/eie/afpmb/docs/techguides/tg41.pdf
  
  Excerpt: Areas with evidence of rodent infestations (e.g., rodent droppings, chewed materials) should be thoroughly treated with a wet disinfectant and cleaned to reduce the possibility of exposure to hantavirus-infected materials. Cleaning procedures must be performed in a manner that limits the potential for aerosolization of rodent-contaminated dust and other materials.
  
  ... Spray the floors and those portions of the walls where evidence of rodent activity is present with a general-purpose disinfectant solution.
  
  ... Spray all buildings with dirt floors with a general purpose disinfectant and wait 30 minutes before use.
• EBPF, GUIDELINE ON BEST PRACTICE IN THE USE OF RODENTICIDE BAITS AS BIOCIDES IN THE EUROPEAN UNION, [PDF] retrieved 2017/11/15 original source: http://www.rrac.info/content/uploads/CEFIC-EBPF-RWG-Guideline-Best-Practice-for-Rodenticide-Use-FINAL-S-.pdf
  Excerpt:
  
  Watch out ..., as mentioned above, it is not recommended to clean up the site as drastic habitat changes will disturb the rodents and may cause them to be wary of the bait and, perhaps, move away to neighbouring buildings. The site may be cleaned when the rodent infestation has been eliminated.
• ECGA, GUIDANCE ON THE BIOCIDAL PRODUCTS REGULATION VOLUME II EFFICACY - ASSESSMENT AND EVALUATION (Parts B+C), [PDF] European Chemicals Agency, (2017) retrieved 2017/11/15 original source: https://echa.europa.eu/documents/ 10162/23036412/bpr_guidance_ assessment_evaluation_part_vol_ii_part_bc_en.pdf/ 950efefa-f2bf-0b4a-a3fd-41c86daae468
• Lange, J. H., P. R. Lange, T. K. Reinhard, and K. W. Thomulka. A STUDY OF PERSONAL AND AREA AIRBORNE ASBESTOS CONCENTRATIONS DURING ASBESTOS ABATEMENT: A STATISTICAL EVALUATION OF FIBRE CONCENTRATION DATA [PDF] the Annals of Occupational Hygiene 40, no. 4 (1996): 449-466.
  Abstract:
  Data were collected and analysed on airborne concentrations of asbestos generated by abatement of different asbestos-containing materials using various removal practices. Airborne concentrations of asbestos are dramatically variable among the types of asbestos-containing material being abated.
  
  Abatement practices evaluated in this study were removal of boiler/pipe insulation in a crawl space, ceiling tile, transte, floor tile/mastic with traditional methods, and mastic removal with a high-efficiency paniculate air filter blast track (shot-blast) machine.
  
  In general, abatement of boiler and pipe insulation produces the highest airborne fibre levels, while abatement of floor tile and mastic was observed to be the lowest
  
  A comparison of matched personal and area samples was not significantly different, and exhibited a good correlation using regression analysis.
  
  After adjusting data for outliers, personal sample fibre concentrations were greater than area sample fibre concentrations. Statistical analysis and sample distribution of airborne asbestos concentrations appear to be best represented in a logarithmic form. Area sample fibre concentrations were shown in this study to have a larger variability than personal measurements.
  
  Evaluation of outliers in fibre concentration data and the ability of these values to skew sample populations is presented.
  
  The use of personal and area samples in determining exposure, selecting personal protective equipment and its historical relevance as related to future abatement projects is discussed Copyright © 1996 British Occupational Hygiene Society.
• Nguyen, Tuan, And Jill Hamilton. ASBESTOS in CRAWL SPACES [PDF] Naval Facilities Engineering Service Center Port Hueneme Ca, 1999.
  Abstract:
  This document has been developed for use by Navy Asbestos Program Managers APM, industrial hygenists, Safety and Health Managers, and facility managers to address asbestos contamination in crawl spaces.
  
  The contents provide direction for managing and abating asbestos hazards in these areas. Section 1 contains primarily the technical and regulatory requirements.
  
  Sections 2 and 3 are checklists with detailed discussions for clean-up or abatement in crawl spaces. These augment the NFESC Field Procedure Manuals for Managing Asbestos Abatement Demolition and Renovation Contracts, TM-2210-ENV and TM-2211-ENV, respectively. Section 4 lists the regulatory and technical references.
• U.S. CDC, CLEANING UP AFTER RODENTS [PDF] retrieved 2017/11/15, original source: www.cdc.gov/rodents/cleaning/index.html
• Umwlet Bundesamt, Reduction of environmental risks from the use of biocides: ENVIRONMENTAL SOUND USE OF DISINFECTANTS, MASONRY PRESERVATIVES AND RODENTICIDES [PDF] Federal Environment Agency (Germany), Umweltbundesamt Wörlitzer Platz 1 06844 Dessau-Roßlau Tel: +49 340-2103-0 Fax: +49 340-2103-2285 info@umweltbundesamt.de Internet: www.umweltbundesamt.de retrieved 2017.11.15 original source: https://www.umweltbundesamt.de/ sites/default/files/medien/378/ publikationen/texte_53_2015_annex_v.pdf

Is there or was there a crawl area sewage spill?

Watch out: entering a crawl space where there has been a sewage spill is hazardous, risking exposure to bacteria and other pathogens even if currently the crawl area is dry.

It's obvious that crawling around through sewage is not healthy unless you are wearing adequate protective gear.

But you may not realize that those same sewage pathogens may be carried on dry airborne dust.

See CRAWL SPACE SEWAGE CLEANUP for details.

Should we Use a Vacuum Cleaner to Clean up the Crawl Space?

Do not use a household vacuum cleaner nor an ordinary shop-vac to clean up crawl space dust and debris. Those machines will temporarily but significantly increase the level of airborne dust and debris.

Since that dust and debris may contain harmful particles, tossing it into the air increases the risk of cross contamination from the crawl space into other building areas such as a basement or even upper floors in the building.

To vacuum and clean surfaces in a crawl area use a HEPA-rated vacuum cleaner that will trap very fine particulates, and select a vacuum cleaner model that does not have air bypass leaks that escape from the equipment when they should be passing through the filter.

Do we need to Set up Dust Containment and Negative Air to Clean Up the Crawl Space?

Negative air machines and dust barriers are procedures used by professional mold remediation companies, asbestos removal experts, and building flood damage restoration companies. These measures reduce the risk of blowing contaminated dust and debris into other building areas - an event which could be a health risk, especially to occupants who are in fragile health. Photo courtesy of Anabec, Inc.

Even an amateur, do-it-yourself cleanup project would benefit from these methods.

But you should recognize when your cleanup project needs the help of a professional. Here are some examples of conditions that mean you should hire a professional to clean up a crawl area:

There is asbestos material that needs to be removed

• The area contains a large reservoir of harmful mold, more than 30 square feet of contiguous moldy material
• The area has been contaminated with sewage and sewer backups
• The people who plan to do the cleanup are not fit, healthy, and properly dressed and equipped
• Other building occupants are at particular risk of health effects from stirred-up building dust that may contain mold, fiberglass insulation fragments, bacterial, viral, or other hazards. Examples are the elderly, infants, asthmatics, people suffering from COPD, or people suffering from MCS.

Watch out: See MOLD / ENVIRONMENTAL EXPERT, HIRE ?

and DO IT YOURSELF MOLD CLEANUP.

Should we use a Power Washer to Clean up the Crawl Space?

If there is room to work, a power washer is a very effective way to clean surfaces, but the increase in water and moisture in the crawl space can make mold or other building-related moisture conditions worse.

In some circumstances such as a crawl area or basement that can be well ventilated, in dry weather, that is well drained, and where other measures are taken to avoid sending a surge of moisture upstairs, power washing might be possible.

Alternative dry-spray surface cleaning methods called media blasting include use of dry-ice spray and baking soda or other abrasive particles, even sand or walnut shell fragments.

See MOLD CLEANUP by MEDIA BLASTING. Our photo shows the ceiling over a basement after cleaning by media blasting.

CRAWL SPACE SEWAGE CLEANUP

...

Continue reading at CRAWL SPACE DEBRIS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these CRAWL SPACE CLEAN UP FAQs - questions & answers posted originally on this page

Or see these

Recommended Articles

• ANIMAL ENTRY POINTS in BUILDINGS - home
• CRAWL SPACE ACCESS
• CRAWL SPACE CLEAN UP
• CRAWL SPACE DEBRIS
• CRAWL SPACE DISINFECTANTS & SANITIZERS, SOURCES
• CRAWL SPACE DRYOUT - home
  • CRAWL SPACE DEHUMIDIFICATION
  • CRAWL SPACE DRY-OUT PROCEDURE
  • CRAWL SPACE GROUND COVERS
  • CRAWL SPACE MOISTURE BARRIERS
  • CRAWL SPACE SEAL & SANITIZE
  • CRAWL SPACE WATER ENTRY STOP
  • CRAWL SPACE WATERPROOFING
• CRAWL SPACE INSULATION RETROFIT
• CRAWLSPACE MOLD ADVICE
• CRAWL SPACE SAFETY ADVICE
• CRAWL SPACE SEWAGE CLEANUP
• CRAWL SPACE VAPOR BARRIER LOCATION
• CRAWL SPACE VENTILATION CODES
• CRAWLSPACE MOLD ADVICE

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