Dampproofing and Waterproofing AHA (Activity Hazard Analysis / Job Hazard Analysis)
Updated 2026-06-23
A Dampproofing and Waterproofing AHA (Activity Hazard Analysis / Job Hazard Analysis) is the plan that keeps the crew doing dampproofing and waterproofing safe from the coating chemical, solvent vapor, and flammability, from the confined space and below-grade excavation, and around the skin contact and hot application. Dampproofing and waterproofing applies moisture-protection coatings and membranes — combining the coating-chemical-solvent-vapor and flammability hazard, the confined-space and below-grade-excavation hazard, and the skin-contact and hot-application hazard. This guide walks through building a Dampproofing and Waterproofing AHA that names the coating-chemical-solvent-vapor/flammability, confined-space/below-grade-excavation, and skin-contact/hot- application hazards and assigns the chemical, confined-space/excavation, and contact controls that hold up in the field.
Why dampproofing and waterproofing needs its own AHA
Dampproofing and waterproofing is the application of moisture-protection coatings and membranes — the dampproofing (moisture-resistant coatings) and waterproofing (waterproof coatings and membranes) applied to below-grade walls, foundations, and surfaces to keep water and moisture out. This heads the dampproofing/waterproofing cluster (dampproofing, bituminous, cementitious follow). The defining feature is the moisture-protection application, which brings chemical hazards (the coatings — solvent-based products with flammable/toxic vapors, and hot-applied products), and the location hazards (much of this work is below grade against foundation walls, often in excavations or confined spaces — the excavation, confined-space, and access hazards). The hazards combine the coating-chemical-solvent-vapor and flammability (applying the coatings/membranes — the chemical hazard (solvent- based coatings have flammable and toxic vapors)), the confined-space and below-grade-excavation (the below-grade location — the excavation and confined-space hazards (working below grade against foundation walls in excavations or confined spaces)), the skin-contact and hot-application (skin contact with the coatings and hot-applied products — the contact/burn hazards), and the eye. The coating-chemical-solvent-vapor/flammability and the confined-space/below-grade-excavation justify a dedicated AHA.
Breaking dampproofing and waterproofing into steps
The steps for a Dampproofing and Waterproofing AHA follow the work:
- Assess the location (excavation/confined space, ventilation)
- Set up excavation/confined-space protections and ventilation
- Prepare the surface
- Apply the dampproofing/waterproofing coating or membrane
- Manage the chemical, confined-space, and contact hazards
- Protect and inspect the application
- Backfill or complete
- Complete
Each step carries a hazard, and the coating-chemical-solvent-vapor/flammability, the confined-space/below-grade- excavation, and the skin-contact/hot-application are where the most significant risks concentrate.
The hazards step by step
Coating-chemical-solvent-vapor and flammability
Applying the coatings/membranes — the chemical hazard (solvent-based coatings have flammable and toxic vapors). The controls are coating-chemical/solvent-vapor safety (dampproofing and waterproofing coatings are often solvent- based (asphaltic/bituminous cutbacks, solvent-based membranes and primers) with flammable and toxic vapors — a fire/flash and health hazard, so ventilation, eliminating ignition sources, flammability control, respiratory protection where needed, and following the product safety data — this is especially critical below grade/in confined spaces where vapors accumulate), and the chemical controls. The coating-chemical-solvent-vapor/ flammability is the primary defining hazard — solvent-based coatings have flammable/toxic vapors. (These follow the solvent-coating fundamentals.)
Confined-space and below-grade-excavation
The below-grade location — the excavation and confined-space hazards (working below grade against foundation walls in excavations or confined spaces). The controls are excavation and confined-space protections (much dampproofing/ waterproofing is applied below grade against foundation walls, often in excavations (the excavation must be protected — cave-in protection/sloping/shoring per the excavation requirements, since workers are down in the excavation next to the wall) or in confined spaces (crawlspaces, tanks — confined-space evaluation and entry procedures), and the accumulation of coating vapors in these below-grade/confined spaces makes ventilation critical), and the confined-space/excavation controls. The confined-space/below-grade-excavation is a defining hazard — the work is below grade in excavations/confined spaces. (These follow the excavation and confined-space fundamentals.)
Skin-contact and hot-application
Skin contact with the coatings and hot-applied products — the contact/burn hazards. The controls are skin-contact and hot-application protection (the coatings contact the skin (chemical skin contact — gloves, skin protection), and some waterproofing is hot-applied (hot rubberized asphalt and hot-applied membranes are applied molten — a severe burn hazard, requiring the hot-application burn controls), so skin protection for the coatings and burn protection for hot-applied products), and the contact/burn controls. The skin-contact/hot-application is a defining hazard — coating skin contact and hot-applied burns. (These follow the chemical-contact and burn fundamentals.)
Eye
The eye (coating splash, vapors) carries the eye hazard. The controls are eye protection (coating splash and vapors), and the eye controls. (These follow the eye-protection fundamentals.)
A simple Dampproofing and Waterproofing AHA structure
| Step | Hazard | Control | Standard |
|---|---|---|---|
| Assess | Confined space | Assess the location (excavation/confined space, ventilation) | OSHA 1926.1200 |
| Protections | Cave-in / vapor | Set up excavation/confined-space protections and ventilation | OSHA 1926.652 |
| Prepare | Chemical | Prepare the surface | project |
| Apply | Flammable vapor | Apply the dampproofing/waterproofing coating or membrane | OSHA 1926.59 |
| Contact | Chemical / burn | Manage the chemical, confined-space, and contact hazards | project |
| Complete | Chemical | Protect and inspect the application; backfill or complete | project |
Coating-chemical control and confined-space/excavation safety
A Dampproofing and Waterproofing AHA centers on coating-chemical control and confined-space/excavation safety. The coating-chemical control addresses the solvent-based coatings — controlled by coating-chemical/solvent-vapor safety (ventilation, ignition-source elimination, flammability control, respiratory protection where needed, critical below grade). The confined-space/excavation safety addresses the below-grade location — controlled by excavation and confined-space protections (cave-in protection, confined-space entry procedures, ventilation for accumulating vapors). And the skin contact, hot application, and eye get contact/burn and eye controls. An AHA built on coating-chemical control and confined-space/excavation safety, with contact controls, addresses the hazards that define dampproofing and waterproofing.
From the field: what actually goes wrong
In fourteen years across federal, heavy civil, and industrial projects, dampproofing and waterproofing applies the moisture-protection coatings and membranes to below-grade walls, foundations, and surfaces, and it heads the dampproofing/waterproofing cluster. Its defining hazards are the coating chemicals and the below-grade location, which interact dangerously. The coating-chemical-solvent-vapor and flammability hazard is a primary defining concern — dampproofing and waterproofing coatings are often solvent-based (asphaltic/bituminous cutback products, solvent-based membranes and primers) with flammable and toxic vapors, so they present both a fire/flash hazard and a health hazard, controlled by ventilation, eliminating ignition sources, flammability control, respiratory protection where needed, and following the product safety data. This is especially critical because of the second defining hazard.
The confined-space/below-grade-excavation is the location hazard, and it interacts with the coating vapors. On the projects I have run, much dampproofing and waterproofing is applied below grade against foundation walls, which means working down in excavations (where the excavation must be protected against cave-in — sloping, shoring, or a protective system per the excavation requirements, since workers are down in the trench/excavation next to the wall) or in confined spaces (crawlspaces, tanks, pits — requiring confined-space evaluation and entry procedures), and critically, the solvent vapors from the coatings accumulate in these below-grade and confined spaces (vapors are often heavier than air and settle into excavations and confined spaces), creating a serious flammable-vapor and toxic-atmosphere hazard, so ventilation is critical. The combination of solvent-coating vapors and a below- grade/confined space is a dangerous one. And the skin-contact/hot-application hazard is skin contact with the coatings (gloves, skin protection) and, for hot-applied waterproofing (hot rubberized asphalt and hot-applied membranes applied molten), a severe burn hazard. The eye hazard rounds it out. The AHA built on coating-chemical control and confined-space/excavation safety is the one that protects the waterproofing crew.
The bottom line
A Dampproofing and Waterproofing AHA names the coating-chemical-solvent-vapor/flammability, the confined-space/ below-grade-excavation, and the skin-contact/hot-application hazards with specific controls — coating-chemical/ solvent-vapor safety (ventilation, ignition-source elimination, flammability control — solvent coatings have flammable/toxic vapors), excavation and confined-space protections (cave-in protection, confined-space procedures, critical ventilation for accumulating vapors below grade), and skin-contact and hot-application protection. The coating-chemical control and the confined-space/excavation safety are the defining concerns. The AHA that manages both is the one that protects the crew.
Frequently asked questions
What coating-chemical hazards apply?
Dampproofing and waterproofing coatings are often solvent-based (asphaltic/bituminous cutback products, solvent-based membranes and primers) with flammable and toxic vapors, presenting both a fire/flash hazard and a health hazard. Controls are coating-chemical/solvent-vapor safety (ventilation, eliminating ignition sources, flammability control, respiratory protection where needed, following the product safety data, especially critical below grade), and the chemical controls.
Why is the below-grade/confined-space location a critical hazard?
Much dampproofing/waterproofing is applied below grade against foundation walls, meaning working in excavations (which must be protected against cave-in) or confined spaces (crawlspaces, tanks — requiring entry procedures), and the solvent vapors from the coatings accumulate in these below-grade/confined spaces (vapors often settle into excavations/confined spaces), creating a serious flammable-vapor and toxic-atmosphere hazard. Controls are excavation and confined-space protections (cave-in protection per the excavation requirements, confined-space evaluation and entry procedures, critical ventilation for the accumulating vapors), and the confined-space/excavation controls.
What contact and hot-application hazards apply?
The coatings contact the skin (chemical skin contact), and some waterproofing is hot-applied (hot rubberized asphalt and hot-applied membranes applied molten — a severe burn hazard). Controls are skin-contact and hot-application protection (skin protection for the coatings, burn protection for hot-applied products), and the contact/burn controls.
What is dampproofing and waterproofing?
Dampproofing and waterproofing is the application of moisture-protection coatings and membranes — the dampproofing (moisture-resistant coatings) and waterproofing (waterproof coatings and membranes) applied to below-grade walls, foundations, and surfaces to keep water and moisture out. Because the coatings are often solvent-based (flammable/toxic vapors), the work is below grade in excavations/confined spaces (where vapors accumulate), and there is skin contact and hot application, those hazards apply.
Related AHAs and JHAs
- Dampproofing AHA — the dampproofing detail
- Bituminous Dampproofing AHA — the bituminous dampproofing
- Preparation for Re-Roofing AHA — the related moisture-protection prep
- Waterproofing Installation JHA — the waterproofing-installation fundamentals
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.