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Photograph of  asbestos slab ceiling insulation, tremolite asbestosAsbestos Fireproofing & Sound or Moisture Control Coatings in Buildings
S olid asbestos fireproofing & spray-on products

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Asbestos-containing building fireproofing materials & coatings: identification, history, properties, use, photographs, hazards.

Photographs of Tremolite asbestos in buildings SPRAY-ON FIRE-RESISTANT MATERIALS May or May Not Contain Asbestos.

This article includes photographs of contemporary spray-on fire-resistant coatings that do not contain asbestos but that may resemble older asbestos-containing materials.

This article describes common asbestos fireproofing materials used in buildings on ceilings and walls. We have not prepared but will add description of spray-on fiberglass coatings used on steel columns and ceilings in high rise buildings such as the lower floors of the NY World Trade center.

This document assists building buyers, owners or inspectors who need to identify asbestos materials (or probable-asbestos) in buildings by simple visual inspection. We provide photographs and descriptive text of asbestos insulation and other asbestos-containing products to permit identification of definite, probable, or possible asbestos materials in buildings.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Asbestos Fireproofing- Tremolite Asbestos-containing Spray-on or Slab (Tremolite) Fireproofing in buildings

Photograph of  LARGER IMAGE - asbestos slab ceiling insulation, tremolite asbestos showing exposed ends projecting over a basement partitionAsbestos Fireproofing - Asbestos-containing Spray-on or Slab (Tremolite) Fireproofing in buildings - How to recognize asbestos fireproofing materials in buildings.

Asbestos containing spray coatings were applied to many building surfaces and components for fire-resistance but also as an acoustic coating for sound reduction on roofs, walls, under floors, as a coating to prevent condensation on surfaces, and for other reasons we describe below.

Asbestos spray coatings are most often found on the underside of roofs, on steel structural members and on steel-reinforced concrete beams and posts, under floors in multi-floor commercial buildings, on paneling, and on some plumbing fixtures such as tubs and sinks.

Asbestos-sprays were used as undercoatings on automobiles, trucks, buses as well, often with an asphalt-based top coat.

In construction an asbestos spray may also have been used as a gap or crack filler to control drafts or for cosmetic purposes.

In addition, slabs of solid asbestos were sometimes adhered to building sufaces for fire protection, such as the boiler room asbestos ceiling coating shown in our photograph just above. [Click to enlarge any image]

While an expert lab test using polarized light microscopy may be needed to identify the specific type of asbestos fiber, or to identify the presence of asbestos in air or dust samples, many asbestos-containing building products not only are obvious and easy to recognize, but since there were not other look-alike products that were not asbestos, a visual identification of this material can be virtually a certainty in many cases.

Also see ASBESTOS DUCTS, HVAC a field identification guide to visual detection of asbestos in and on heating and cooling system ducts and flue vents.

Also see Micro-Photographs of Dust from the World Trade Center collapse following the 9/11/01 attack. Links to U.S. government and other authoritative research and advice are included.

Asbestos based building fireproofing materials including both the thick Tremolite asbestos panels below, chrysotile asbestos panels and asbestos-containing paints and coatings for fire resistance, are described here.

Photograph of  asbestos slab ceiling insulation, tremolite asbestos

Slabs of 1" thick asbestos insulating board, typically 6" wide, were used as fireproofing on commercial building ceilings and possibly walls.

According to some experts, this material is usually Tremolite asbestos, a particularly hazardous form of asbestos which occurs as both fibrous asbestiform (see 1st lab micro photograph) and non-fibrous granular form which in our samples includes high percentage of ultra-small sub-micron asbestos particulates (see 2nd lab micro photograph).

This material when viewed overhead from below, can appear to be simple concrete.

But a closer look shows its fibrous nature, and inclusions which do not resemble concrete. Unlike cementious asbestos board, this material is soft, very friable, and easily damaged or disturbed. [This tremolite insulation was removed from the building by experienced professional asbestos abatement workers. It should not be handled by amateurs.]

Microphotographs taken in our forensic laboratory show what this particular asbestos material looks like under high magnification and polarized light.

See ASBESTOS UNDER the MICROSCOPE.

Not commonly used in single family residences or small buildings, but common in high-rise buildings into the 1970's, including the lower floors of the World Trade Center, leading to asbestos fiber release at "ground zero" on 9/11/00. At some locations where this material was sprayed on the under-side of steel roofing and on steel columns, it may be hidden by finish materials and enclosures.

ASBESTOS FOAM LAMINATES discussed in ASBESTOS INSULATION included fire resistant foam boards, wallpaper and similar products.

Historic / Traditional Use of Spray On Asbestos Coatings

Keasbey Mattisons Sprayed Limpet Asbestos advertisement (C) InspectApedia.com[Click to enlarge any image]

Asbestos sprayed "limpet" asbestos coatings were used for resisting surface condensation, fire-resistance, fireproofing, soundproofing (as an asbestos acoustic coating) on building surfaces, pipes, and as an undercoating on sinks and bathtubs.

Sprayed-on asbestos coatings were produced by a number of companies in the U.S. and other countries. In the U.S. spray-on asbestos was produced and applied as early as 1930 (Turner & Newall Limpet Spray) and continued in use into 1975 (Kaiser Gypsum K-Spray textured ceiling asbestos coating).

Limpet asbestos is a brown asbestos product composed principally of amosite asbestos or amphibole asbestos having coarse asbestos fibres that supported adhesion on the sprayed-on surface and good heat resistance.

We found some sources describing limpet asbestos as including crocidolite (blue asbestos) and also chrysotile (white asbestos).

Above: an advertisement for Keasbey Mattison's sprayed "limpet" asbestos coating promoting its use as sound conditioning at the U.S. Air Force Academy. The company describes spraying on a 1 1/2" thick coating of asbestos to provide four hours of fire-retardancy as well as sound deading.

Sprayed on withg a gun, SPRAYED "LIMPET" ASBESTOS goes on in any kind of weather, as long as the temperature at point of application is above 40F. Sets fast and dries fast. No nailing, cutting, fitting, or clipping. No forms or shoring. Minimum clean -up time and labor. Thermal insulation, condensationcontrol, and fire retardation are other uses of SPRAYED "LIMPET" ASBESTOS.

High Power Microscopic Image of World Trade Center Collapse Dust collected at the siteLimpet asbestos spraying was performed using compressed air, water from a reservoir tank, and bagged dry asbestos mixed with cement. The equipment mixed water, the asbestos/cement, and compressed air to coat the sprayed-on surface.

W.R. Grace was a major supplier of Monokote®, a spray-on chrysotile (white asbestos) asbestos coating materials. Monokote® contained varying levels of asbestos from 5 to 50% in the spray coating mixture, typically along with cement, depending on the application.

In some applications sprayed-on asbestos coatings were then topped with an asphalt-based "tar" for durability or weatherproofing, providing a sound-deadening coating similar to asbestos-asphalt-mixed coatings used in automotive underbody coatings.

Some sources refer to this coating as hand-trowled on blackjack tar but that description is inaccurate as the coating was not tar but was asphalt-based.

Asbestos spray coating was used up to the 65th floor of the U.S. World Trade Center and was released over a very wide area during the 9/11/2001 WTC collapse.

See WTC DUST PARTICLE - MICRO PHOTOGRAPHS

Asbestos Automotive body undercoating (underbody coating), also applied by spraying, is described

at ASBESTOS OTHER PRODUCTS.

History of Asbestos & Asphalt-Asbestos Spray Coatings
& other Uses of Asbestos on Bathtubs & Sinks

White asbestos spray coating on a bath tub in New York (C) Daniel FriedmanBelow: a spray-on bathtub coating that may contain asbestos, observed by the author [DF] during a building renovation and repair project in New York.

Spray-on coatings on sinks and bathtubs, sometimes also covered with an asphalt-based top coat, were used to reduce problems with moisture condensation on the tub exterior.

Besides an asbestos spray or otherwise applied coating on a bathtub exterior, there were other tub exterior coatings that might have been used, including asbestos paper, felt, plaster or gypsum or simply paint.

US Patent research that we conducted gives a partial picture of the use of asbestos in various forms on bath tubs beginning as early as 1900.

Spray-on Asbestos Coating or Insulation Manufacturers & Products

Contemporary Spray-on Fire Resistant Building Coatings & Materials That do Not Contain Asbestos

Spray on fireproofing on steel construction DF 2008

Some modern spray-on building fireproof or fire-resistant coatings look a bit like products used in the 1970's and prior, but the new materials do not contain asbestos as its use in this application is now prohibited.

Continue reading in this article using direct links to the sections listed below, or

The photograph of building construction with a spray-on fire resistant coating t above was taken in the Bronx, New York, in 2008.

Below: Spray-on fire-resistant coating in the Duluth MN airport in October 2018.

Spray on fireproofing coating Duluth MN airport (C) Daniel Friedman at InspectApedia.com

Current spray-on fire-resistant coatings do not contain asbestos and include both wet and dry insulation coatings, and cementious fireproofing coatings (such as fire resistant plaster) installed by a variety of fire-resistant coating and insulating companies who may apply an insulating layer, fire retardant paint, intumescent paint & coatings (polyvinyl ace tate resins and inorganic fillers designed for the fire protection of interior structural steel), cementious coatings, etc.

Spray on fireproofing coating Duluth MN airport (C) Daniel Friedman at InspectApedia.com

These fire-resistant products are produced and sold by W.R. Grace, Isolatek / Cafco, Albi, Southwest Vermiculite, International Cellulose, and others. Spray insulating products cover a still wider range including foam insulating products (and some fire-resistant foam products used typically at building penetrations and other special applications).

Asbestos Test Results for Spray-On Fireproofing

The Germania Bank Building in 2009 - Wikipedia

Manufacturers Hanover operated the Germania Bank Building (b. 1898-1899) building shown above, 190 Bowery as a branch bank up to the mid-1960s.

Spray on fireproofing in an antique bank vault, The Bowrey, New York City (C) Daniel Friedman at Inspectapedia.com

The building was designed in a Renaissance Revival or Beaux Arts style by Robert Maynicke and was built in 1898–99. Currently a private residence, it was made a New York City designated landmark on March 29, 2005. - Wikipedia ret. 2020/04/05

Below we include images of the bank vault located in the basement and of spray-on fire-resistant coating applied to various surfaces in that area.

Spray on fireproofing in an antique bank vault, The Bowrey, New York City (C) Daniel Friedman at Inspectapedia.com

Here we show the use of spray-on fire-resistant insulation in the Germania building bank basement as it appeared in 2017.

Spray on fireproofing in an antique bank vault, The Bowrey, New York City (C) Daniel Friedman at Inspectapedia.com

Sample No. 08: Location: 190 Bowery, New York City, Old bank building used as Totokaleo store temporary location, collected 2017/12/02

Spray on fireproofing insulation test sample from NYC (C) Daniel Friedman at InspectApedia.com

Fireproofing spray insulation test results

Spray on fireproofing insulation test sample from NYC (C) Daniel Friedman at InspectApedia.com

The lab characterized this fire-resistant spray as "tan, fibrous, homogeneous (not entirely, see our photos), and identified

Sample 08 Spray on fireproofing insulation asbestos test result (C) Inspectapedia.com EMSL

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2023-12-28 by InspectApedia Publisher (mod) - would asbestos fireproofing spray have been used on my home's roof or soffits?

Seneca Howland house, Pleasant Vallery NY shows basic house parts sucvh as soffit, eaves, fascia, barge board, gable end (C) Daniel Friedman at InspectApedia.com

@Anonymous:

I apologize for my earlier challenge about your question; for the last few months we've been deluged with hundreds short questions like yours, mostly about asbestos, and that appeared to come from the same source.

The "Soffit" is the portion of a roof that extends past the building walls and overhangs the building exterior. On most roofs the soffit is enclosed so that you can't directly see the underside of the roof.

Asbestos fireproofing spray roof coating was not normally used on 1-4 family residential buildings. So you wouldn't expect to find it on your home unless you live in a high-rise building or are in a commercial building.

In those buildings an asbestos fireproof spray, as illustrated above on this page, was applied to the entire underside of the roof - visible if the under-side of the roof deck is accessible from inside the building. Whether or not that same spray continued to the building exterior roof underside (under a soffit) would have been a very small area and the roof over a soffit would not have been so treated by itself.

Fireproofing spray that used asbestos was also applied to the underside of floors in high-rise buildings, as became a concern when the World Trade Center towers collapsed at the 9-11-2001 terrorist attack.

To clarify these house parts see

HOUSE PARTS, DEFINITIONS

where we define "roof soffit" as

Soffit or lookout or house eaves.

The soffit is the enclosed portion of the roof that overhangs the house walls at the roof lower edges. The construction of a typical roof overhang, eave or soffit is shown in our sketch [at the top of that article] - also shown in our photo of the Seneca Howland house in Pleasant Valley, NY - above in this discussion.

Post a photo of the underside of your roof as viewed from your attic (one photo per comment) and use another comment to post a photo of your roof eaves or overhang or "soffit" and we can comment further.

On 2023-12-28 by Anonymous - what is underside of roof? is it soffit? - where would asbestos spray-on insulation be used?

what is underside of roof? is it soffit?

residentially, where would asbestos spray on insulation be used?

@InspectApedia Publisher, no i am not chat bot, and i am asking becuase i had a leaking roof. Since you said asbesots spray on insulation was apllied on underside of roof. I am worried, but when i did some reserach it siad the underaide of roof is called soffit on the outside. that is why i wanted to confirm what do you mean underside of roof.

On 2023-06-26 by InspectApedia Publisher (mod)

@Patti,

No.
That is not a safe assumption.

Asbestos products were manufactured in a complete range of textures and a wide range of hardness, from smooth cementious board through soft insulation through paste and lagging and fabrics.

Take a look at the stunning range of asbestos products at ASBESTOS LIST of PRODUCTS https://inspectapedia.com/hazmat/Asbestos_Products.php

On 2023-06-26 by Patti

My attic where my furnace is, is lined with smooth 12" x 12 panels about 1/2 inch thick screwed in. Not able to get a photo but, isn't asbestos always rough/bumpy like?

On 2022-11-21 by InspectApedia (Editor) (mod)

@Carla,

The photo is a bit blurry so I'm not sure but it looks as if we are seeing gypsum board. Also known as drywall. On a ceiling.

And in hour photo it looks as if that surface is quite moldy - I'd be looking for the source of leakage, and I'd have the drywall removed and the exposed surfaces cleaned.

Depending on the country of manufacturer and the age of that material drywall or joint compound use at drywall joints good indeed contain asbestos.

I certainly don't see any spray on fireproofing such as discussed on the page above.

On 2022-11-21 by Carla

Moldy ceiling - not spray asbestos fireproofing (C) InspectApedia.com Carla

This is an image from an apartment building. Might this contain asbestos?

On 2022-08-31 by InspectApedia (mod)

@Caroline V,

Try again to include a photo by using the Add Image button.

On 2022-08-31 by Caroline V

Hi -- I am interested in a condo that was built in 1981. Attached is a picture of the garage. The owner and building manager say it is not asbestos but I'm concerned. Do you know what this could be?

On 2022-02-06 by Inspectapedia Com Moderator (mod)

@Kelly Cozad,

Continuing...if you could post a photo, it may help us identify the substance.

You can only attach one image per comment but can post as many comments as you wish.

On 2022-02-06 by Inspectapedia Com Moderator (mod)

@Kelly Cozad,

No, the spray on asbestos fireproofing products used on building surfaces would not be a black tar immaterial. More likely they would be gray and thick and fibrous.

There are some black adhesive mastic and black Asphalt Coatings that were used as foundation waterproofing or tile adhesive have contained asbestos fibers though not generally in a friable condition.

It would be really unusual to find anyone spraying such an unsuitable material onto the covers of a heating unit.

On 2022-02-06 by Kelly Cozad

I live in a 1970 mobile home that has a furnace cabinet where the walls are spray coated with a black tar looking substance, probably asbestos?

On 2019-12-27 by danjoefriedman (mod) - possible asbestos fireproofing spray-on coating falling off of a ceiling

I cannot say by visual exam if that falling insulation contains asbestos or not, Howard; It may make sense to have a sample tested since in any case it ought not be falling off the ceiling; there may be both an asbestos issue and a fire hazard.

Indeed the texcture and color of the falling spray-on insulation and the building age both suggest that this could be an asbestos-containing material.

If you decide to have it tested, do let us know the result: that may help other readers.

And in any event you want to diagn ose the cause of the fallling material: if it's due to leaks that needs to be repaired.

On 2019-12-27 by HOWARD LOEWENSTEIN

let me add to my just previous comment this loose/falling insulation is coming from the boiler room plant ,from off the metal ceiling above.

Possible asbestos-containing fireproofing spray falling off of a ceiling (C) InspectApedia.com Lowenstein H

I am trying to see if you may know if this is asbestos or contains asbestos at all, its from a large govenrment public parks building opened in 1979.

Possible asbestos-containing fireproofing spray falling off of a ceiling (C) InspectApedia.com Lowenstein H

On 2019-03-03 y danjoefriedman (mod)

Eric I think we're seeing the edge of plaster board or gypsum board panels - that might contain asbestos, but is definitely not a spray-on coating.

On 2019-03-03 by Eric

We have this in our house. Looks like metal flakes in it. Its not an even thickness so it may be sprayed on over some drywall.

[Image lost by Comment Box]


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