Flooring and Carpeting/Bitumen adhesive
QUESTION: Hi, I've written to you before and you had given me very help and reassuring answer. I have another query. The asbestos tiles have been removed yesterday and now there is a thin layer of asbestos bitumen adhesive left on top of the concrete floor. The contractor sprayed the bitumen with a product called PVC which he said to bind the bitumen so that no asbestos fibres will be released. Is bitumen adhesive left on concrete completely safe? Will it be OK to switch the dehumififiers on to complete the drying process? (Water damage due to burst pipe). Thank you for your help.
ANSWER: Please note: The trick using the boiling water to determine asbestos may NOT work on your adhesive since your contractor sprayed it with something (PVC).
---------- FOLLOW-UP ----------
QUESTION: The bitumen adhesive do contains asbestos as it has been tested in the lab. So is it safe to leave on concrete floor? The contractor did not remove all of the bitumen.
I had actually written the following to you but only the note about the testing was sent. Here is what I wrote in full:
It is safe unless you start to scrape it or abrade it in some manner and get the particles airborne and you inhale it. It is ok to run the dehumidifiers. Drying the air is not the same as scraping or abrading the adhesive. However, drying the air and walking on the dried adhesive could lead to airborne particles or particles on your footwear. You stated that your contractor used a product called "PVC" to bind the adhesive. I am not familiar with that product. So I would not know how well that product would keep the asbestos from becoming airborne or attaching itself to your footwear if you walk on it. To be safe you will want to have the adhesive recovered with carpet once your drying is done. If you need to walk over the adhesive you may want to lay down kraft paper (available at Lowes or Home Depot, etc.) in the walkway once the concrete is dry and prior to carpet replacement. Then you can simply throw the kraft paper away.
The trick to determine asbestos is to spill boiling water on an exposed area. If the water puddles, you have cut-back adhesive (contains asbestos). If the adhesive melts, you do not.
(This may not work if it has been treated).
Please be aware that your choices are limited in what flooring you can put over the old adhesive. Carpet is ok but manufacturers of some resilient products will not warranty their products over cut back adhesive or adhesive that has been removed or treated by the use of solvents. Many abatement professionals use solvents to remove "cut back". These solvents absorb into the slab, where they remain. The presence of the solvent residue can cause a reaction with some hard surface floor coverings, especially it's adhesive causing failure and/or discoloration on the new product's surface. The Resilient Floor Coverings Institute, which sets industry standards, specifically disclaims warranty of new floors installed under such circumstances. If you do have asbestos "cut back" mastic, and it MUST be removed,there are nonsolvent products that work in the removal process; Franmar industries sells Beeno and there are also citrus products used in the remediation process. The concrete must be allowed to completely dry prior to the installation of ANY flooring.