Why is encapsulating asbestos a recommended practice?

November 25, 2024 12:00 AM

I have some asbestos tile in the kitchen underneath the carpet. Everyone says that if asbestos isn't friable, it's ok to encapsulate it so stray fibers don't get into the air. Don't disturb it, it's fine! However, it will eventually become friable, and then you must remediate. Why is the typical advice to put off asbestos remediation until it is even more hazardous to remediate?
posted by Mirth to Home & Garden (12 answers total)

Anecdotally (I was once married to a civil engineer), every structure has a finite lifespan. Remediation usually happens at demolition, not at a remodel. The technology and services available are presumed to be better (and cheaper) in the future than they are today, so do your best to keep things stable as long as possible and sort out the expensive, tightly regulated clean-up when it comes time to replace the whole thing or whatever other big event you're planning for.
posted by late afternoon dreaming hotel at 2:54 AM on November 25 [16 favorites]

Why is the typical advice to put off asbestos remediation until it is even more hazardous to remediate?

Because it is better to remediate a hazard than to create one.

Asbestos bound up in a stably installed building product in such a way as to bind its fibres and keep them out of the air isn't a hazard. Same cannot be said for the broken pieces that removal will inevitably create. So unless the material is already in such a state of deterioration as to create an imminent risk of spontaneous and ongoing fibre release, there is no hazard present that could justify the small but nonzero fibre release risk inherent in even the best-conducted asbestos remediation works.
posted by flabdablet at 3:32 AM on November 25 [10 favorites]

it will eventually become friable

If it's bound up in cement sheet or vinyl or linoleum floor tile, no it won't. Not unless subjected to heavy wear or being bashed about.
posted by flabdablet at 3:38 AM on November 25 [7 favorites]

It's about cost and not creating problems where there isn't one. Our ability to make durable encapsulation is very good and relatively inexpensive which makes preventing asbestos exposure the first and standard solution. The cost of removal is many times, often a full magnitude, larger than remediation. It doesn't become more of a problem later - it's essentially the same issue.

That's because this is an issue that is a binary. There are a range of options to mitigate the risk of exposure but when you cross the threshold into actual exposure then asbestos removal from than environment has to be undertaken. Both the risk and the cost of asbestos removal is much higher.

Maybe you plan on staying there forever (or 20 years), or maybe the though of paying to remediate now and then pay for removal later seems like a poor financial choice or maybe a short term period of higher risk is work a long term of nearly zero risk. But remediation, by design, has a very very low risk associated with it.
posted by zenon at 7:53 AM on November 25 [4 favorites]

Response by poster: Thank you all for your insights! I am still confused.

If it's bound up in cement sheet or vinyl or linoleum floor tile, no it won't [become friable]. Not unless subjected to heavy wear or being bashed about.

This is contrary to some things I've read which say it will eventually become friable simply due to aging of the asbestos-containing material. If I understand correctly, that's why ongoing testing is required after schools do asbestos encapsulation.

The technology and services available are presumed to be better (and cheaper) in the future than they are today

I understand why someone would be inclined to say that - on average, taking a long view, that has been the case for much of human history. Over the short term, though, I don't see any guarantee that technology and services won't get worse and more expensive. Also, this building is in a region where it will likely be destroyed by natural disaster, at the same time as many other buildings. If that happens, the asbestos will no longer be contained within one room, it will be further fragmented, and professional asbestos removal will be in extremely high demand.

So... Maybe there's a magnitude-of-risk thing that I'm not understanding the scale of? In which case numbers or graphics would be really helpful (I haven't found those in anything I've ready yet). Because right now it seems like encapsulation is the standard because it's so much less expensive and the risk is considered acceptable, not because it's actually best practice.
posted by Mirth at 9:15 AM on November 25

Best answer: Just my opinion, but one reason encapsulation is an option is that if removal were the only allowed route, because it's so expensive people would DIY removal or ignore the asbestos, which is a worse outcome.

Encapsulation is relatively inexpensive and limits harm vs the alternative of no encapsulation.
posted by zippy at 11:53 AM on November 25 [4 favorites]

You can also just get some quotes from licensed (or whatever the correct term is) asbestos abatement companies. If you can stomach the cost, presumably they remove it in a manner that is safe for the home owner. If you’re looking at the difference between $500 to encapsulate and $5,000 to remove, that might be clarifying to your decision making process.
posted by Number Used Once at 1:03 PM on November 25

Asbestos in tile is different than asbestos for insulation material, in terms of how likely it is to get friable and be disturbed, etc. A flat material attached to the floor with some kind of mortar is less likely to get all crunched up and become airborne than some flexible material wrapped around a pipe that is exposed to air and light and movement, for instance. Asbestos itself doesn't decay. And if you think of how often someone needs to replace floor tile vs. other aspects of a house, to me, that's one of the best contexts for just putting another layer on top, if the tile is in good shape.
posted by slidell at 2:39 PM on November 25 [1 favorite]

Best answer: A school or other high use setting will see considerably more wear, which alters the timeline/level of risk and a major factor will be liability. That frequent retesting is to id if the encapsulation is working or not. Somewhere there’s an actuary table that plots the costs of actually fixing the problem against the insurance premiums. The last time I dealt with asbestos at work they just removed all access- that was the easiest/cheapest way to deal with it.

You are right that it’s a ‘just good enough’ solution. Disasters are a huge issue- famously the World Trade Center Towers destruction released a huge amount of asbestos and repeated exposure to that certainly contributed to folks who cleaned getting sick and dying. I’ve been exposed a few times, I’m fine… but folks in the trades like I was are often cavalier about these risks right up until it gets them.
posted by zenon at 3:40 PM on November 25 [1 favorite]

A flat material attached to the floor with some kind of mortar is less likely to get all crunched up and become airborne than some flexible material wrapped around a pipe

And a flat material glued to the floor and protected from wear and oxidation by underlay and carpet over the top is thoroughly protected from degradation of the binder.

My own house was built in the 1950s and has asbestos cement sheet lining the laundry walls and ceiling. It's painted on the interior side but not on the wall cavity side. When we took out the wall between the laundry and the bathroom we got an asbestos removal guy in to deal with the sheeting being removed from that wall, and his advice was that the act of replacing the rest of it, even using all his standard precautions, would release more asbestos fibre than would ever escape if we just left it all in place. Which, given that his standard precautions are designed to reduce fibre release to very low levels, I found quite reassuring.

Given that our asbestos cement sheeting is fully exposed to air on its reverse side and supported by being nailed to a timber frame, it's subjected to way more vibration than your under-carpet floor tiles. If you plan to remodel at some point, by all means get your asbestos tile professionally dealt with but until then I wouldn't be at all worried about it.
posted by flabdablet at 6:28 PM on November 25 [2 favorites]

I am wondering about carpet in the kitchen. Is this wall-to-wall? How do you clean it? (to me it seems less than ideal to have carpet in a place where there are often drips and accidents on the floor.) Specifically, I'm wondering if any friable asbestos fibers can migrate up through the carpet. If you have carpet cleaning, wouldn't that destabilize the asbestos underneath if it was damaged or old? I would also hesitate to have small kids crawling around or playing on the floor.

I suspect it would be safer to remove the carpet (consult an asbestos removal pro about how to do this safely) and install something like less permeable hardwood or vinyl flooring on top of the asbestos floor.
posted by citygirl at 7:13 AM on November 26

Response by poster: I've been thinking about this some more. In the 80s and 90s when asbestos was being phased out, people didn't have easy access to internet videos and professional explainers.

Advice for dealing with asbestos is based on the assumption that the average DIYer wouldn't have access to the professional knowledge to safely remove asbestos. If the advice were being developed in the 2020s, widespread availability of safe removal practices might be more of a factor. I think if asbestos practices were developed today, people would be told to "Take all asbestos safety precautions during removal, we mean it! Otherwise encapusulate or hire it out." because this would mean less need to externalize the problem by creating a situation where more people have to work in asbestos removal, with it's dangerous chronic exposure.
posted by Mirth at 9:33 AM on November 28