Elastomeric Sheet Waterproofing AHA (Activity Hazard Analysis / Job Hazard Analysis)

An Elastomeric Sheet Waterproofing AHA (Activity Hazard Analysis / Job Hazard Analysis) is the plan that keeps the crew doing elastomeric sheet waterproofing safe from the adhesive, primer, and seam chemicals, from the below- grade excavation and confined space, and around the membrane handling and sharp tools. Elastomeric sheet waterproofing applies elastomeric sheet-membrane waterproofing — combining the adhesive-primer and seam-chemicals hazard, the below-grade-excavation and confined-space hazard, and the membrane-handling and sharp-tool hazard. This guide walks through building an Elastomeric Sheet Waterproofing AHA that names the adhesive-primer/seam- chemicals, below-grade-excavation/confined-space, and membrane-handling/sharp-tool hazards and assigns the chemical, excavation, and handling/tool controls that hold up in the field.

Why elastomeric sheet waterproofing needs its own AHA#

Elastomeric sheet waterproofing is the application of elastomeric sheet-membrane waterproofing — the flexible elastomeric/rubber sheet membranes (EPDM, butyl, and similar sheet membranes, or self-adhering elastomeric sheets) applied to below-grade walls, foundations, and structures as a waterproofing membrane. This heads the sheet/fluid waterproofing cluster. The defining feature is the cold-applied sheet-membrane installation (no hot work, unlike the built-up systems): the adhesives, primers, and seam chemicals (used to adhere the sheets and seal the seams — potentially solvent-based), the below-grade location (excavation/confined space), and the membrane handling and cutting. The hazards combine the adhesive-primer and seam-chemicals (adhering the sheets and sealing the seams — the adhesive/primer/seam-chemical hazard (potentially solvent-based — flammable/toxic vapor)), the below-grade-excavation and confined-space (the below-grade location — the excavation and confined-space hazards), the membrane-handling and sharp-tool (handling the membrane rolls and cutting the sheets — the handling and cut hazards), and the eye. The adhesive-primer/seam-chemicals and the below-grade-excavation/confined-space justify a dedicated AHA.

Breaking elastomeric sheet waterproofing into steps#

The steps for an Elastomeric Sheet Waterproofing AHA follow the work:

• Assess the location (excavation/confined space, ventilation)
• Set up excavation/confined-space protections and ventilation
• Prepare and prime the surface (primer chemicals)
• Cut and position the elastomeric sheets (sharp tools)
• Adhere the sheets and seal the seams (seam chemicals)
• Manage the chemical, below-grade, and handling hazards
• Inspect and protect; backfill or complete
• Complete

Each step carries a hazard, and the adhesive-primer/seam-chemicals, the below-grade-excavation/confined-space, and the membrane-handling/sharp-tool are where the most significant risks concentrate.

The hazards step by step#

Adhesive-primer and seam-chemicals

Adhering the sheets and sealing the seams — the adhesive/primer/seam-chemical hazard (potentially solvent-based — flammable/toxic vapor). The controls are adhesive/primer/seam-chemical safety (elastomeric sheet waterproofing uses primers, adhesives, and seam sealants/tapes to adhere the sheets and seal the seams, and these can be solvent-based (contact adhesives, primers, seam cleaners/primers) with flammable and toxic vapors — a fire/flash and health hazard, so ventilation, eliminating ignition sources where solvent-based, skin/eye protection, flammability control, and following the product safety data — critical below grade where vapors accumulate), and the chemical controls. The adhesive-primer/seam-chemicals is the primary defining hazard — the primers/adhesives/ seam chemicals can be solvent-based flammable-vapor hazards. (These follow the solvent-adhesive fundamentals.)

Below-grade-excavation and confined-space

The below-grade location — the excavation and confined-space hazards. The controls are excavation and confined-space protections (elastomeric sheet waterproofing is applied against below-grade walls and foundations, in excavations (cave-in protection per the excavation requirements) or confined spaces (confined-space procedures), with ventilation critical because the adhesive/primer vapors accumulate below grade), and the below-grade/confined-space controls. The below-grade-excavation/confined-space is a defining hazard — the work is below grade in excavations/confined spaces. (These follow the excavation and confined-space fundamentals.)

Membrane-handling and sharp-tool

Handling the membrane rolls and cutting the sheets — the handling and cut hazards. The controls are safe membrane handling (the elastomeric sheet-membrane rolls — handling, and the self-adhering sheets are sticky/awkward), safe cutting (cutting the sheets to fit — utility knives, sharp-blade cut hazard, cutting away from the body, cut- resistant gloves), and the handling/cut controls. The membrane-handling/sharp-tool is a defining hazard. (These follow the material-handling and knife-safety fundamentals.)

Eye

The eye (primer/adhesive splash, vapors) carries the eye hazard. The controls are eye protection (primer/adhesive splash and vapors), and the eye controls. (These follow the eye-protection fundamentals.)

A simple Elastomeric Sheet Waterproofing AHA structure#

Adhesive/seam-chemical control and excavation/confined-space safety#

An Elastomeric Sheet Waterproofing AHA centers on adhesive/seam-chemical control and excavation/confined-space safety. The adhesive/seam-chemical control addresses the primers/adhesives/seam chemicals — controlled by adhesive/primer/seam-chemical safety (ventilation, ignition-source elimination where solvent-based, flammability control, critical below grade). The excavation/confined-space safety addresses the below-grade location — controlled by excavation and confined-space protections (cave-in protection, confined-space procedures, ventilation for accumulating vapors). And the membrane handling, cutting, and eye get handling/cut and eye controls. An AHA built on adhesive/seam-chemical control and excavation/confined-space safety, with handling/cut controls, addresses the hazards that define elastomeric sheet waterproofing.

From the field: what actually goes wrong#

In fourteen years across federal, heavy civil, and industrial projects, elastomeric sheet waterproofing applies flexible elastomeric/rubber sheet membranes to below-grade walls and foundations, and unlike the built-up systems, it is cold-applied (no hot work), so its defining hazards shift to the adhesive chemistry and the below-grade location. The adhesive-primer and seam-chemicals hazard is a primary defining concern — elastomeric sheet waterproofing uses primers, adhesives, and seam sealants or tapes to adhere the sheets to the substrate and seal the seams between sheets, and these can be solvent-based (contact adhesives, primers, and seam cleaners/primers are often solvent-based) with flammable and toxic vapors, presenting both a fire/flash hazard and a health hazard, so adhesive/primer/seam-chemical safety (ventilation, eliminating ignition sources where solvent-based, skin/eye protection, flammability control, following the product safety data) is a control — and this is critical below grade where the vapors accumulate. The solvent-based adhesive and seam chemicals are the defining chemical concern.

The below-grade-excavation/confined-space and the membrane-handling/sharp-tool are the other defining hazards. On the projects I have run, elastomeric sheet waterproofing is applied against below-grade walls and foundations, meaning working in excavations (cave-in protection per the excavation requirements) or confined spaces (confined-space procedures), with ventilation critical because the adhesive/primer vapors accumulate below grade. And the membrane-handling/sharp-tool hazard is handling the elastomeric sheet-membrane rolls (which are handled, and self-adhering sheets are sticky and awkward) and cutting the sheets to fit (utility knives — the sharp-blade cut hazard, cutting away from the body, cut-resistant gloves). The eye hazard rounds it out. The AHA built on adhesive/seam-chemical control and excavation/confined-space safety is the one that protects the elastomeric- sheet-waterproofing crew.

The bottom line#

An Elastomeric Sheet Waterproofing AHA names the adhesive-primer/seam-chemicals, the below-grade-excavation/ confined-space, and the membrane-handling/sharp-tool hazards with specific controls — adhesive/primer/seam- chemical safety (ventilation, ignition-source elimination where solvent-based, critical below grade), excavation and confined-space protections (cave-in protection, confined-space procedures, ventilation for accumulating vapors), and safe membrane handling with safe cutting. The adhesive/seam-chemical control and the excavation/ confined-space safety are the defining concerns. The AHA that manages both is the one that protects the crew.

Frequently asked questions#

What adhesive and seam-chemical hazards apply?

Elastomeric sheet waterproofing uses primers, adhesives, and seam sealants/tapes to adhere the sheets and seal the seams, and these can be solvent-based (contact adhesives, primers, seam cleaners/primers) with flammable and toxic vapors, presenting a fire/flash and health hazard. Controls are adhesive/primer/seam-chemical safety (ventilation, eliminating ignition sources where solvent-based, skin/eye protection, flammability control, following the product safety data, critical below grade), and the chemical controls.

What below-grade hazards apply?

Elastomeric sheet waterproofing is applied against below-grade walls and foundations, meaning working in excavations (requiring cave-in protection) or confined spaces (requiring confined-space procedures), with ventilation critical because the adhesive/primer vapors accumulate below grade. Controls are excavation and confined-space protections (cave-in protection, confined-space procedures, ventilation for accumulating vapors), and the below-grade/confined-space controls.

What handling and cut hazards apply?

Handling the elastomeric sheet-membrane rolls (self-adhering sheets are sticky/awkward) and cutting the sheets to fit (utility knives) bring handling and cut hazards. Controls are safe membrane handling, safe cutting (cutting away from the body, cut-resistant gloves), and the handling/cut controls.

What is elastomeric sheet waterproofing?

Elastomeric sheet waterproofing is the application of elastomeric sheet-membrane waterproofing — the flexible elastomeric/rubber sheet membranes (EPDM, butyl, similar sheets, or self-adhering elastomeric sheets) applied to below-grade walls, foundations, and structures. Because the primers/adhesives/seam chemicals can be solvent-based (flammable/toxic vapor), the work is below grade in excavations/confined spaces, and the membrane is handled and cut, those hazards apply.

Related AHAs and JHAs#

• Sheet Dampproofing AHA — the related sheet dampproofing
• Fluid-Applied Waterproofing AHA — the fluid-applied waterproofing
• Bentonite Waterproofing AHA — the related bentonite waterproofing
• Waterproofing Installation JHA — the waterproofing-installation fundamentals

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Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.