Cement Board Siding Asbestos Exposure

Cement Board Siding and Historical Asbestos Use

Asbestos-cement siding was historically produced in rigid shingles, sheets and panels. Asbestos fibers were used as reinforcement in a cement matrix, helping create a durable exterior product that resisted heat, moisture and weathering.

OSHA historically identified asbestos-cement siding, shingles and flat sheet among asbestos-containing construction products. These products were different from ordinary wood siding, aluminum siding and modern fiber-cement siding.

The presence of cement alone does not establish asbestos content. Product identification should consider the manufacturer, trade name, installation date, dimensions, edge profile, fastening system and available records.

Types of Cement Board Siding and Applications

Depending on manufacturer, formulation and year, asbestos may historically have been associated with:

• asbestos-cement siding shingles;
• flat asbestos-cement siding sheets;
• rigid cementitious exterior panels;
• lap-style asbestos-cement siding products;
• cement board panels used on residential or commercial exteriors;
• decorative asbestos-cement siding units;
• asbestos-cement products used around soffits, gables or exterior wall sections; and
• related sheathing products or paneling products installed in the same wall assembly.

The related Siding Products Asbestos Exposure page discusses a broader range of historical siding materials. The Concrete Asbestos Products Asbestos Exposure page covers other cementitious asbestos products such as pipe, flat sheet and specialized building materials.

Modern non-asbestos fiber-cement products can resemble older asbestos-cement siding, so appearance alone is not enough to determine composition.

How Asbestos Exposure Could Occur

A potential exposure pathway requires asbestos-containing siding and a task that releases fibers into the air. Intact cement board can bind fibers within a hard matrix, but aggressive mechanical work can disturb that material.

Potential disturbance could occur during tasks such as:

• sawing siding boards or shingles to length;
• drilling holes for fasteners or fixtures;
• grinding or shaping panel edges;
• breaking brittle siding during removal;
• removing nailed or screwed asbestos-cement panels;
• repairing cracked or weather-damaged siding;
• demolishing exterior wall assemblies;
• cutting openings for windows, doors, vents or utilities; and
• dry sweeping or blowing dust after cutting or removal.

OSHA asbestos rules for cementitious asbestos-containing siding and shingles emphasize avoiding unnecessary cutting, abrading and breaking and generally favor removing panels as intact as possible. Actual exposure depends on asbestos content, work method, material condition, dust generation, duration, frequency, proximity, ventilation and cleanup practices.

Workers and Job Sites That May Have Encountered Cement Board Siding

Workers who manufactured, cut, installed, repaired or removed historical asbestos-cement siding may have encountered airborne fibers. A job title alone does not establish exposure; the exact product and task matter.

Potentially relevant occupations may include siding installers, carpenters, construction laborers, roofers, remodelers, maintenance workers, painters, electricians, utility workers and demolition crews.

Possible settings include homes, apartment buildings, schools, hospitals, offices, industrial buildings, warehouses, military facilities and other structures where cement board siding or asbestos-cement shingles were installed.

Workers nearby could also have encountered dust if siding was dry-cut, drilled, broken or removed in the same work area.

Cutting, Repair and Removal Risks

Cutting and drilling

Field fitting siding often required cutting around corners, windows, doors and vents. If the board contained asbestos, sawing or drilling could generate fine cementitious dust containing fibers.

Weathering and breakage

Older cement board siding can become brittle with age, impact or repeated weather exposure. Cracked panels may break during repair or removal and create debris.

Repair work

Replacing only a few damaged boards can still disturb original siding, especially where panels overlap or fasteners must be removed. Drilling or prying should be evaluated carefully when asbestos-containing material may be present.

Removal

OSHA asbestos work practices for cementitious asbestos-containing siding favor removing panels intact and minimizing cutting, abrading and breakage. Breaking panels into smaller pieces can increase dust generation.

Demolition

Whole-building demolition can fracture exterior siding along with wall framing and sheathing. If asbestos-cement siding is present, appropriate asbestos procedures may be required before general demolition begins.

Evidence That May Identify Historical Cement Board Siding

Product identification is strongest when physical characteristics are combined with historical records. Appearance, age and gray cement-like color are not enough to prove asbestos content.

Useful evidence may include:

• manufacturer names or molded markings;
• brand names and product numbers;
• original bundles, wrappers, cartons or labels;
• manufacturer catalogs and siding brochures;
• architectural specifications and exterior finish schedules;
• purchase orders, invoices and supplier records;
• siding contractor and subcontractor records;
• building permits and renovation records;
• historic photographs showing the siding pattern or packaging;
• asbestos surveys, bulk-sample reports and abatement records;
• employer, union or military records documenting assignments;
• coworker or supervisor statements identifying products and work methods; and
• qualified laboratory analysis of surviving siding material when appropriate.

Testing should distinguish the siding itself from underlying sheathing, caulk, paint, insulation and other adjacent materials whenever those components can be separately identified.

Medical and pathology records may document an asbestos-related diagnosis but do not establish which historical siding product was an exposure source.

Secondhand Exposure and Health Risks

If cutting or removal of asbestos-containing cement board siding generated dust that accumulated on work clothing, shoes, tools or belongings, fibers could potentially have been carried away from the job site. This is a possible secondhand exposure pathway, but family relationship alone does not establish exposure.

Asbestos exposure is associated with mesothelioma, asbestos-related lung cancer, asbestosis and other asbestos-related disease. Working with old cement board siding does not diagnose disease and does not establish individual medical causation.

Anyone concerned about historical occupational asbestos exposure should discuss their work history and health with a qualified healthcare professional.

Legal and Compensation Considerations

Depending on the evidence and circumstances, legal options may be available to a person diagnosed with an asbestos-related disease after documented exposure to a specific asbestos-containing cement board siding product.

A legal review may consider the manufacturer, brand, formulation, installation dates, building or job site, tasks performed, frequency and duration of exposure, diagnosis, jurisdiction and applicable filing deadlines.

Identifying a manufacturer or supplier does not automatically establish legal responsibility. Liability is case-specific and depends on product evidence, exposure evidence and governing law.

Some matters may involve asbestos trust funds, but each trust has its own product, exposure and medical documentation requirements. Eligibility is not automatic, and compensation is not guaranteed.

Exposure that occurred decades ago does not by itself determine whether a claim is timely. Statutes of limitation and other deadlines vary by jurisdiction and circumstances and should be reviewed individually.

Cement Board Siding Asbestos Exposure FAQs

Did old cement board siding contain asbestos?

Some historical cement board siding did. Asbestos-cement shingles, sheets and siding products were manufactured for many years, but not every cement board product contained asbestos.

Is modern fiber-cement siding the same as asbestos-cement siding?

No. Modern fiber-cement products generally use non-asbestos reinforcing fibers. Product age and manufacturer records are important when identifying older siding.

Could cutting cement board siding release asbestos fibers?

Yes, if the board contained asbestos. Sawing, drilling or grinding can create dust and disturb fibers bound in the cement matrix.

Could removing intact panels reduce dust?

Generally, yes. OSHA asbestos work practices for cementitious asbestos-containing siding emphasize minimizing cutting, abrading and breakage and removing panels as intact as possible.

Can asbestos-cement siding be identified by appearance?

No. Similar-looking cementitious siding can have different formulations. Historical records or qualified laboratory analysis may be needed.

Could nearby workers be exposed during siding removal?

Potentially. Dust from cutting, breaking or drilling asbestos-containing siding may affect workers in the same area depending on distance, ventilation and work practices.

What evidence can identify old cement board siding?

Useful evidence can include manufacturer markings, catalogs, invoices, architectural specifications, contractor records, photographs, asbestos surveys, laboratory reports and coworker testimony.

Does working with old cement board siding automatically qualify someone for compensation?

No. Legal eligibility depends on identifying asbestos-containing material, establishing exposure, documenting diagnosis, jurisdiction and other case-specific evidence. Compensation is not guaranteed.

Get Help Reviewing Historical Cement Board Siding Exposure

If you or a family member has been diagnosed with mesothelioma, asbestos-related lung cancer or another asbestos-related disease and you are trying to identify older cement board siding, asbestos-cement shingles or exterior panels from a workplace, construction project or military facility, we can help organize the product and exposure history that may be relevant.

Call 800.291.0963 to discuss what you remember about the product, markings, building, job site and work performed. Live chat is available 24/7, 365 days a year. Submit Your Case using the form below.

Prior exposure does not automatically establish a legal claim. Eligibility depends on the evidence, diagnosis, jurisdiction and other circumstances, and compensation is not guaranteed.

⚕️ Legal & Medical Information Disclaimer
This page provides general educational information and is not medical or legal advice. The information does not establish asbestos exposure, diagnosis, causation, liability, claim eligibility or compensation. Medical concerns should be discussed with a qualified healthcare professional, and legal questions should be reviewed with a qualified attorney.