Asbestos and Linoleum Flooring

The black mastic beneath true linoleum is often hide glue. (Basically a super version of Lepages glue. It is water soluble.)

I repeat – that black stuff may very well be water soluble. Sanding is pointless because it’s hard as iron after 60 – 80 years underfoot.

If you actually have linoleum, it’s probably from the 1920’s thru the 1940’s. Chances are it doesn’t have asbestos in it. Linoleum is made with linseed oil, sawdust, pigments and sometimes a jute fiber backing. Linseed oil (ie flaxseed oil) is edible although there isn’t much salvage linoleum I’d be willing to put in my mouth. (Although with all the hemp in there I might be willing to smoke it…)

To remove mastic:

You need a pan of super hot water. In a small out of sight area and try slopping quite a bit of water on the spot (use a car sponge to rapidly saturate it). Let it stand for only a couple of minutes then take a scraper and try scraping it up. It will move and dissolve if it’s hide glue.

If this IS hide glue, you have to work very fast and dry out the wooden sub flooring as you saturate,then scrape. I used a blow dryer and later a heat gun. You don’t want to have your wood “potato chip” after you scrape the stuff off.

I did this to a stairway and a hallway and although the hardwood underneath did deform a little, after a year or two the minor warping disappeared.

The tar or contact cement style glue used with vinyl (a la hancockone’s excellent post above) probably needs oil based solvents to remove.

this may help too. From the JohnBridge.com tile forum:
To clear things up a bit….. Linoleun was a specific type of sheet goods made from cork (Armstrong Cork Co.) and other materials for decoration. Linoleum hadn’t been used much since the ’50’s. The backing of linoleum was made of paper, usually black/brownish or sometimes it was greenish in color. You may have heard the term “battleship linoleum”? It was used on military ships to reduce the splintering of wooden decks when enemy shells hit their mark. I doubt if linoleum contained asbestos in its surface layer, paper backing or the water soulable paste usually used to install it?

What is often reffered to as linoleum is really sheet vinyl. Sheet vinyl came (comes) is many grades and widths. The very tough type of sheet vinyl is made by aranging tiny particles of vinyl chips/flakes into a pattern, this type of sheet vinyl is called “inlaid vinyl”. Inlaid vinyl comes only in 6′ widths because of its weight and therefore would be impossible to handle in wider rolls. When “experts” say you can install other floors directly over sheet vinyl floors in good condition, they are talking about this type of ‘hard-non-cushioned’ sheet vinyl.

The other type of sheet vinyl is made by the ‘rotogravure’ method. Rotogravure is like printing a newspaper. This type of flooring starts with a backing, to which a thin foam chemical is applied. As the chemically uncured foam is applied, another chemical is also applied in the design pattern of the desired flooring. It is them ‘baked’ to cure. The foam rises as it cures except where to 2nd chemical was applied preventing that area from rising, thus the texture of sheet vinyl. The material continues to the coloring/printing process and finally the wear layer. The wear layer is a clear sheet of vinyl anywhere from 2-3 mills upto maybe 20 mills thick. This type of flooring is ‘cushioned’ even though it doesn’t feel all that soft in many cases. These floors can be 6′, 9′ 12′ even 13’6″ wide. DO NOT install good flooring or CBU”S directly over this type of flooring.

In the 1960’s the flooring industry developed a ‘better’ backing for their mid to upper grade sheet flooring. The old basic paper backing was suseptable to heel and appliance indentation because to paper was soft. Armstrong introduced ‘hydrocord’ as their better backing. Hydrocord was made from asbestos, it was off-white in color, about 1/16″ thick. This type of backing was replaced by other types in the early to mid ’80’s.

Although these backings contain asbestos, most do not believe they create any danger unless you sand and breath the dust over a lengthy period of time, or eat the material. (dogs) Having said that, I DO NOT suggest anyone dry sand or scrape materials that might contain anything harmfull. Procedures have been developed for the safe removal of certain flooring materials that contain asbestos. As far as I know the adhesives used for sheet vinyl do not and did not contain asbestos. Adhesives for sheet vinyl were either water-based, (old linoleum paste) or latex based. As far as I know only some of the old black asphalt-based (cut-back) contained asbestos. Again not a problem, just don’t sand it.

I agonized over the same decision for a while, and contemplated the costs of having somebody do it professionally, and just did it myself.

I would assume the tiles contain asbestos. This type did well into the 70’s and perhaps even beyond. However, it is not considered “friable” asbestos, so the risk is minimal.

You will inevitably break these tiles into shards trying to remove them, so keeping them wet will help keep down the minimal amounts of asbestos that get released into the air when they break. I experimented with various scrapers and stiff putty knives. If the adhesive is holding very well, this could be quite a chore. I might experiment with heat to soften up the the adhesive. (Somebody is going to blast me for that).

Regarding the adhesive, you can find good, even non-toxic solvents that will soften it up and allow you to mop it up. Let me know if you need a name. Have got some at home.

I’d vote for getting it tested first. You can scrape up some of the black glue and include it with with linoleum samples to be tested. There is a place in the city near Penn station that does testing. If it comes back negative just pry the linoleum up up with a crow bar and you are set. When we had our floors redone the guys just came in and sanded off all the black adhesive when they did the floors. They came out great. If there is asbestos then, you are probably in for some expense to get it dealt with. Definitely not worth taking any risk with. Also, just for clarity’s sake, asbestos is a fairly common mineral and it is mined.