et&t general structural remediation guidelines

8/14/2019 et&t general structural remediation guidelines

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General Guidelines Structural Mold Remediation

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GENERAL GUIDELINES -STRUCTURAL MOLD REMEDIATION

This document outlines the general guidelines for structural mold remediation for use by ourcustomers and remediation contractors. These guidelines are to be used in conjunction withthe specific remediation details outlined in our reports. It discusses the general principles,evaluation criteria, containment types, and work procedures for mold remediation. It isassumed that these guidelines will be used by trained, experienced and preferably certifiedmold remediation professionals. Professionals should be familiar with the industry guidelinesand standards.

1. General Principles

Carefully review our scope of work to assure that all outlined work areas are addressed in the

contractors work plan. A mold problem in a building is always a moisture problem. Therefore,all sources of water and moisture intrusion must be identified and eliminated. A logicalsequence of work should be established and may include procedures not mentioned in theseguidelines. Deviations are acceptable as long as the intent of environmental and personalprotection remains the same. The contractor must follow all applicable local, state and federalregulations when using personal protection equipment.

2. Material Evaluation Criteria

The treatment of mold contaminated building materials depends on its porosity, exposedsubstrates and the ability to adequately restore the material. The following table representsthe generally accepted treatment procedures for building materials affected by fungal

amplification (actual mold growth)1

. Materials containing multiple layers of differing porositiesshould be carefully evaluated on a case by case basis.

MATERIALCATEGORY

MATERIALS TREATMENT

Porous Drywall, ceiling tiles, insulation,particle board, medium densityfiberboard (MDF), carpet, etc.

Discard, except in rare cases

Semi-porous Wood, brick, plaster, block, concrete,plywood, oriented strand board (OSB),etc.

Abrasive methods:

Wire brushing, sanding,media blasting, etc.

Non-porous Glass, metal, Formica, plastic,porcelain, ceramic tile, etc.

Surface cleaning:

Damp wiping, HEPAvacuuming, etc.

1IICRC S520 Standard and Reference Guide for Professional Mold Remediation


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Porous building materials are primarily organic materials that readily absorb moisture and arehighly susceptible to fungal growth. Semi-porous building materials are materials that absorb

water slowly and are susceptible to fungal growth. Non-porous building materials arematerials that do not absorb moisture and do not support fungal growth, although, growth canoccur on surface dirt films. These non-porous materials may be organic, synthetic or inorganicmaterials or which have been altered to be non-absorbent.

3. Engineering Controls

The objective of a remediation project is the removal or treatment of the affected materialswithout causing additional damage or airborne exposure to the occupants and unaffectedareas of the building. Removal of mold-contaminated building materials can create extremelyhigh airborne spore concentrations as well as dust in the work area. Therefore, remediationcontractors need to be knowledgeable with the principles of isolation, air flow management,containment and dust suppression methods, and the selection and use of personal protectionequipment.

4. Isolation and Containments

The type of containment method used is dependent on the size of the affected materials, theconfiguration of the space, the ease of cleanup and economics. Containments generally areseparated into three basic types: Source, Local and Full Containment2. Please review yourreport for the type selected for your project.

Sealing off of interstitial spaces, penetrations, electrical outlets, drain lines, etc. may benecessary to prevent air infiltration and to manage air flow. We recommend removing carpetsfrom inside the containment work area. If carpets can not be removed they need to becontained and protected by 6 or 10-mil polyethylene sheeting material (poly) and tape.

4.1 Source Containments

Source containments are used for relatively small areas of visible mold growth in conjunctionwith other engineering controls. Such methods include covering the affected area with plasticsheeting or self adhesive plastic before removal and immediate bagging or wrapping ofaffected materials before removal from the site.

The floors should be protected. Dust and debris should be immediately HEPA vacuumed.

Removal of affected materials should be performed with little agitation as possible (dustcontrol methods) to prevent spore and dust aerosolization. Use of N-95 respirators and glovesis recommended3.

2New York City Guidelines

EPA Mold Remediation in Schools and Commercial Buildings GuidelinesACGIH Bioaerosols: Assessment and Control3

ACGIH Bioaerosols, EPA


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4.2 Local Containments

Local or mini containments are used for moderate amounts of visible fungal growth orsuspected hidden mold growth. A structural enclosure is created around the work area andcovered with 6-mil poly. A negative pressure differential in the work area is recommended.Local containments are usually negatively pressurized through the use of HEPA filtered airfiltration devises (AFD) to manage the air flow in the work area. Refer to section 5 for furtherinformation. Personal protection equipment should be used in the work area. Decontamination(decon) chambers may or may not be necessary or specified.

4.3 Full Containment

Full-scale containments are used when significant or extensive visible mold growth is presentor suspected and local or source containment methods are not effective or economically

feasible. The entire room or building section is designated as the work/containment area andno structural enclosure is built. Prior to the start of the remediation the interior surfaces mayneed to be sealed off with poly if they can not be effectively cleaned. A negative pressuredifferential should be created in the work area. Personal protection equipment should be usedin the work area. A decontamination chamber (decon) is usually placed at an entry door.

5. Pressure Differentials

Pressure differentials are used to manage airflow. A minimum negative pressure differential of5 Pascal or 0.02 inches of water gauge in the work area is generally recommended. Ifpressure differentials are used, they should be created by using HEPA filtered AFDs. Inspecialized environments, such as health care facilities systems, manometer with data logging

and/or alarm capability is highly recommended.

6. Decontamination Chambers

Decontamination chambers are attached to local or full containment to provide a transitionalspace between the work area and surrounding areas. They provide an area fordecontamination of demolition debris and workers. The number of decon chambers variesdepending on the project and the contractors professional judgment.

7. Material Removal

Affected porous materials, such as drywall, should be removed 1 or 2 feet beyond (or one

stud bay beyond) the area of visible mold growth and/or water damage.

The extent and degree of the mold contamination may only be visible during the demolitionprocess. The contractor needs to inspect the adjacent remaining materials to insure that theyare free of visible mold growth.

Abrasive methods can be used to clean affected wood framing. If the structural integrity of thematerial is lost during the cleaning process, replacement is necessary.


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Immediately bag or wrap demolition debris in 6-mil polyethylene bags or sheeting materialbefore removal from the work area. If local or full containments are being utilized, bag or wrap

the material before removal from the containment.

Wood rot should be removed 2 to 3 feet beyond visible decay and be evaluated for structuralintegrity by a knowledgeable contractor, engineer or architect.

Remove all the baseboards in the remediation area to assess if additional water or molddamage is visible in areas previously unsuspected. Inspect the backside of baseboard and theexposed drywall materials

8. Deep Cleaning

After the demolition work has been completed, deep cleaning of all interior surfaces in the

work area is required. Deep cleaning is used to remove settled dust, mold spores and fungalfragments from interior surfaces. HEPA-filtered vacuum cleaners shall be used. All remainingsurfaces in the work area should be vacuumed and damp wiped.

The use of HEPA filtered scrubbers prior to clearance testing is very helpful in removingairborne dust, mold spores and fungal fragments from the work area.

9. Misting

Misting is a method of atomizing water as a vapor in the air for the purpose of controllingairborne and surface dust and mold spores. We generally do not recommend misting.However, appropriate misting techniques in conjunction with adequate engineering controlsfor dust suppression and clean up purposes may be considered. Misting is not wetting.

10. Encapsulants

We generally do not recommend the application of encapsulants because physical removal isthe preferred method. However, if encapsulants are used, do not use pigmented encapsulantson building materials prior to our post remediation inspection. Such encapsulant applicationwill prevent us from visually inspecting and verifying that the mold contaminated materialshave been removed. The use of clear encapsulants is acceptable. The application ofpigmented encapsulant after a passed clearance test is at the discretion of the remediationcontractor.

11. Post Remediation Testing (Clearance Testing)

After the remediation work is completed, but prior to any reconstruction work, a postremediation inspection and testing (clearance testing) should be conducted to assure thatproper decontamination has been conducted prior to reconstruction.

If post remediation testing is requested or required, local or full containments should not beremoved until the work area has passed the post remediation testing. Testing should be


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performed by an independent and experienced indoor environmental consultant or industrialhygienist. ET&Ts post remediation criteria consist of the following parameters:

Work area shall be free of visible mold growth.

Work area shall be free of visible dust.

The remaining building materials shall be dry to industry standards.

The airborne total mold spore counts inside the work area shall be lower or similar tothe outside reference air samples.

The type of molds present in the work area shall be similar to outside referencesamples.

If the work site fails the evaluation, additional material removal, re-cleaning or increasing thedilution ventilation may be required. Retesting needs to be performed after additional clean up

work has been performed.

12. Contractor Qualifications

Mold remediation work should be conducted by a qualified, trained, experienced andpreferably certified contractor or company.

13. Personal Protection Equipment

The use of appropriate personal protection equipment such as coveralls, respirators, glovesand the like is highly recommended during demolition and clean up work. The type of personalequipment selected varies with the type of contaminant, the quantity of affected material and

the work time period. Professional judgment in equipment selection is required4

. Thecontractor must follow all applicable local, state and federal regulation when using personalprotection equipment.

14. HVAC Systems

The filter-elements of the heating ventilation and air conditioning equipment should bereplaced as part of the remediation process. We recommend that the HVAC system becleaned, if the system was exposed to significant fungal contamination.

4EPA

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