Removing Bird Excrement from Masonry Buildings

Technical Procedures Disclaimer

Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.

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We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.

PART 1---GENERAL

1.01 SUMMARY

  1. This specification provides guidance on removing small quantities of bird excrement from masonry.

CAUTION: EXPOSURE TO ACCUMULATIONS OF PIGEON EXCREMENT AND ITS AIRBOURNE DUST CAN LEAD TO POTENTIALLY FATAL DISEASES OF THE LUNGS AND CENTRAL NERVOUS SYSTEM SUCH AS HISTOPLASMOSIS AND CRYPTOCOCCOSIS. IT IS IMPORTANT TO FOLLOW THE SAFETY PRECAUTIONS OUTLINED IN SECTION 1.02 B. BELOW WHEN DOING THIS TYPE OF WORK. REVIEW CURRENT HEALTH SAFETY ADVISORIES ON THIS MATTER.

  1. Safety Precautions:

    1. All personnel must wear a National Institute for Occupational Safety and Health (NIOSH) approved full face respirator with a high efficiency particulate air (HEPA) filter for screening particles of 0.3 micron size. Dust and particle masks are not appropriate.

    2. Respirators must be used in accordance with current OSHA regulations and GSA policy relevant to this condition and work. This includes fit-testing of respirators, maintenance, training, storage requirements, disposal of the debris, and other relevant topics.

    3. All personnel must wear protective coveralls, gloves, boots, and hats.

    4. Prior to removal, all excrement must be saturated with water under low pressure to prevent debris from becoming airborne.

    5. On historic structures, only non-metallic tools (such as plastic spatulas and brushes with natural fiber or nylon bristles, or their equivalent) must be used to remove the excrement.

    6. Removed excrement must be collected in plastic bags, sealed, and disposed at a sanitary landfill.

    7. All work must be performed from the outside of the building. Building occupants and the general public must be kept clear of the work site during all operations. It is the cleaning personnel's responsibility to provide all barricades, signage, etc. necessary for public protection.

  2. Read "General Project Guidelines" along with this specification. These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO). The guidelines cover the following sections:

    1. Safety Precautions

    2. Historic Structures Precautions

    3. Submittals

    4. Quality Assurance

    5. Delivery, Storage and Handling

    6. Project/Site Conditions

    7. Sequencing and Scheduling

    8. General Protection (Surface and Surrounding)

PART 2---PRODUCTS

2.01 MATERIALS

  1. Clean, cold water

  2. Chelating agent such as EDTA (ethylene diamine tetra-acetic acid)

    1. NOTE: FOR USE ON ACID-SENSITIVE MASONRY

    2. Acid-sensitive masonry includes limestone, marble, calcareous sandstone, glazed brick, sand-lime brick, architectural terra cotta, and polished granite.

  1. Acidic cleaner containing hydrofluoric acid

    1. NOTE: FOR USE ON NON-ACID-SENSITIVE MASONRY

    2. Non-acid-sensitive masonry includes sandstone, slate, granite, unglazed brick, unglazed terra cotta and concrete.

2.02 EQUIPMENT

  1. Stiff bristle brush (non-metallic)

  2. Wooden scraper

  3. Garden hose

PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

CAUTION: DO NOT USE BLEACH TO REMOVE BIRD EXCREMENT. BIRD DROPPINGS CONTAIN AMMONIA AND IF MIXED WITH BLEACH CAN FORM TOXIC GASES.

  1. Remove heavy crusts and build-up by rinsing the affected area with cold water from a garden hose and brushing with a stiff bristle, non-metallic brush or scraping with a wooden scraper.

  2. NOTE: FOR EXCESSIVE AMOUNTS OF DROPPINGS, APPLY WATER PRESSURE FROM A SAFE DISTANCE AND DO NOT ATTEMPT TOTAL REMOVAL.

  3. For remaining residue, scrub the surface using a stiff bristle, non-metallic brush, a detergent or chelating agent (for acid-sensitive masonry) or acidic cleaner containing hydrofluoric acid (for non-acid-sensitive masonry) and clean, clear water.

  4. Allow the cleaner to stand on the surface for approximately 1 hour or as recommended by manufacturer.

  5. Thoroughly rinse the surface with clean, clear water and allow to dry.