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asbestos mastic - leave it or remove it

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Joined: Jul 8 2003

Hi,

From reading past posts, I understand that it is important to remove asbestos mastic under the asbestos VCT tiles for preparing to install new tiles or linoleum. What about for glueing down engineering bamboo? The installer has removed the carpet and the VCT tiles, and scraped as much mastic as possible, but there are still stubborn black mastic on the slab. He instended to leave the mastic down and glue the bamoo on top of it using urethane adhesive (Bostik Best), saying that the mastic would have no negative effect on the glue and actually could act as a moisture vapor barrier. Should I believe him?

I need advice quickly, so that I can stop him before too late.

Thanks.

Jiong

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Joined: Aug 25 2005

I've done engineered hardwood floors in remodeling jobs and have done some research on which flooring system would be best for an Eichler with radiant heat and on-grade concrete slab.
The best solution to Eichlers is either concrete floors or tile. If you had to go with hardwood, I would suggest a floating floor for a few reasons.
a) With temperature and humidity variances in an Eichler, even a bamboo floor might experience cupping and warping. If you will be gluing down your floors without any vapor barrier, you're just asking for trouble. Don't let him tell you that the glue is a vapor barrier.
b) If you glue your floors down and experience a leak in your radiant heat, you will have to tear up your floors compared to unclicking your floating floor.
c) I cut and pasted an excerpt from I-floor.com explaining which flooring does best on the type of floor you have.
Eichlers are basically on-grade cement floors.

My suggestion: Put this guy on hold and do more research. I don't know what your situation is, but I see countless people making the same mistakes you could be making and that is not doing any research on projects, doing an emergency post on the Eichler Network, regretting it and doing the whole job over again.
The internet has TONS of info on flooring and any project you need to do.
Good luck.

On-Grade, Above-Grade, Below-Grade

Most appropriate installations are considered "on-grade," meaning that the floor is level with the height of the exterior grounds with joists or post-and-beam construction supporting the floor. When installing on-grade, it's important that the crawlspace or basement under the subfloor is well-ventilated. If ventilation is inadequate, moisture will likely result in the cupping or warping of the hardwood months after installation.

"Above-grade," meaning upper floors of a multi-floor house or building may be appropriate for solid wood flooring if the subfloor is wood. Another consideration is the amount of flex in the floor prior to installation. While all floors have (and need) some flexibility, a more rigid floor is necessary for strip solid wood floors.

"Below-grade" situations, such as basements with cement floors, limit your choices considerably. Some parquets, as well as the solid wood Natural Reflections Line from Bruce can be installed over cement using a direct glue method. In general, though, cement floors mean moisture, which spells disaster for hardwood.

Your best bet would be to install an engineered wood floor over a moisture barrier using the floating installation technique.
ifloor.com

Nick
Castro Valley

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Joined: Mar 20 2003

jiong: this topic has been covered many times on this board. I suggest you use the search function to find past threads relevant to your topic.

If you're putting down new tile or linoleum, you should really remove the old tiles and mastic. Also, the old tiles are VAT, not VCT. VCT is a common floor available today. Removing old tiles isn't that big a deal. There are guidelines to follow for DIY, of you can hire an abatement company to do it. Do shop around for the right abatement company. For my 1240 sqft slab, I received bids between $2700 and $7700. We tried DIY, but the tiles were coming up in pieces. But I know folks in Eichlers who popped their tiles up in a few hours, painlessly. As for removing the mastic, Franmar makes a soy based product called beany-doo. Good stuff.

If you want you heating system to function properly, polish the slab, install cork tiles, VCT, or a commercial ceramic tile for your new floor. I really do not suggest any type of wood flooring.

Do post up your progress.

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Joined: Jul 8 2003

I did put in a lot of time researching for new flooring for replacing the old carpet in my eichler. I was swaying back and forth between bamboo and tile, and priced them out each with several contractors. I was almost going to do tiles (even though I have concerns about the hardness and the maintenance of grout lines), until recently I found this reputable bamboo manufacture who warrants their bamboo product for glue down over radiant heat (in fact they specifically recommend against floating over radiant heat). And luckily I found someone who has experiences with this particular installation method. I already have the slab pressure tested (no leaks), moisture content tested (within the range for the bamboo warranty), so I went ahead. For those who still worry about moisture vapor from slab, there is product (Bostik MVP - moistoure vapor protection) to go with Bostik urethane adhesive (Bostik Best) to keep the moisture in check .

My question now is do I need to remove all the mastic to bare slab to be able to use the new urethane glue, or is it OK to leave the stubborn ones? - I guess I already know the answer: that I should, but just double check, because the installer who seems experienced says not necessary, and if I believe him, I can save some money and more importantly time.

Jiong

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Joined: Mar 20 2003

do the right thing and properly remove the old tiles.

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Joined: Jul 8 2003

A little update on my research for solving my problem (I posted the question at hardwoodinstaller.com where a lot of hardwood pros hang out). It seems that I have an alternative to removing the mastic. I can skim coat a cement based floor patch. Here is the excerpt from the contractor who responded:

>
I would skim coat it with ARDEX SD-F. The ARDEX will bond and encapsulate the cutback adhesive residue, and the urethane bamboo adhesive will bond to the ARDEX, but the urethane adhesive could have bonding concerns with the cutback adhesive.
>

I'm going to try verifying with the urethane glue manufacture that ARDEX is recommended for encapsulating the cutback adhesive. Will keep you posted.

Jiong

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Joined: Jul 8 2003

Joe,

I already removed the carpet and the old tiles. It was the black mastic (cutback adhesive) from the old tiles that I was asking about.

Jiong

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Joined: Dec 11 2005

I think I would put the coating over the glue. Glue down floors are not often used on radiant heat due to the fact your floor is right on the cement and the mosture from the floor will loosen the glue over time. Your floors are more likely to be noisy and creak if you do not float it and use a moisture barrier pad underneath it.
I had bamboo floors installed last year and did not pay attention to the advice on this board and I now wish I had. They are faded from sun and have scratches, I used the hardest eco-timber product out there.
Please make sure gluing is really the best idea. Radiant floors are much different than regular and I had 5 quotes on floors and none of them said glue down was the best idea. Did you ask any other installers with experience in Eichlers on their advice?

Visit [url=http://www.marinmodern.com/]MARIN MODERN[/url] to see great modern & mid-century modern homes!

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Joined: Jul 8 2003

I am curious about the fade out of your bamboo floor. What color is it, natural or carbonizied?

It is true that most of the installers I talked to recommended floating the bamboo. But this product I got specifiicallly recommends against floatiing over radiant heat (wiill not warrantee it). Oh well, I've been going through the deciding process for a long time, and I'm focusing on getting this job done RIGHT.

Jiong

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Joined: Dec 11 2005

I have an amber colored carbonized engineered bamboo. If you lift my rug up there is a significant difference. I also have 2 neighbors with the same floor and the same problems. I am sure you have done your research and know what you are getting. I love the look of bamboo and I have seen a really nice glue down bamboo floor at the San Rafael Building department. It seems to withstand a lot of wear and tear, although there are no windows in the office and it has a subfloor. If you have the light color floor and not the amber then you will not have the color issue. Most good flooring companies insist on doing moisture test on your floor before lying down the flooring because the manufacturer will not usually give a warranty if your floor is above a certin level of moisture content. It looks like you have already looked into this though.Good Luck!

Visit [url=http://www.marinmodern.com/]MARIN MODERN[/url] to see great modern & mid-century modern homes!

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Joined: Jul 8 2003

I did get the natural (light ) color, vertical grain. I just hope this will work out well (with my fingers crossed). I am very careful about the process so that I don't void the warranty from
both the manufacture and the installer. The installer has been very supportive. In fact I was talked into this by him - he will gurantee his labor + material if there's any thing wrong (everything is in writing).

Jiong

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Joined: Dec 11 2005

It sounds like you have done your homework. I am glad you have the natural color so you will not have the issues darker bamboo floors have. It is funny how you can ask one question and get a million anwers to a question you never asked.

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Joined: Mar 20 2003

jiong, you may be setting your self up for legal/environmental problems if you don't handle the mastic according to state regulations for handling asbestos. If you just cover, what appears to be exposed mastic, you could be breaking disposal laws for hazardous waste. You, by law, would need to disclose the fact when time comes to sell the home. You really should check with your local hazardous waste regulatory agency to make sure you have done it right.

you can clean your slab in a day with Franmar Bean-e-doo. you'll need to degrease too. Not too hard.

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Joined: Dec 11 2005

This disclosure is a given. Every Eichler owner who has not removed the tiles and adhesive must disclose this issue. There is a hazards brochure given to all homebuyers in California which covers lead based paint and asbestos in homes and discusses vinyl flooring installed between 1920-1972 might have asbestos. It also says the asbestos is not harmful if it is painted over. The asbestos must be in the air in order for it to be harmful. Sealed or painted asbestos is not harmful unless it become friable which means it becomes crushed or pulverised.

Visit [url=http://www.marinmodern.com/]MARIN MODERN[/url] to see great modern & mid-century modern homes!

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Joined: Mar 20 2003

yes, but it doesn't sound like jiong's installer knows the regulations involving asbestos removal. Any tile breaking would have produced friable asbestos. So would have "scraped as much mastic as possible."

some issues I see here:

most states limit asbestos removal to 100 sq ft when someone other than the home owner does the job. Any thing beyond that needed to be a licensed abatement company, which the house is sealed and special cleanup procedures are followed.

since the removal described doesn't sound legitimate, was the clean up handled in the same manner? If so, site contamination is quite likely.

Judging by the questions asked, description of the progress to date, and the mind-set "I can save some money and more importantly time," I would be concerned about the environmental state of this property.

jiong, I hope you don't think I am jumping to an uninformed conclusion, but I just spent several years researching this procedure and had 1240 sqft of tile/mastic removed from my home. I can't imagine Sunnyvale is much different than my town. If it was my town, and if the city caught wind of what was going on, your flooring installer would be fined and your home would be declared a hazard until cleaned up and inspected.

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Joined: Aug 25 2005

Yes, you did some good research on glue down floors.

Nick
Castro Valley

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Joined: Aug 8 2008

As far as I am concerned all asbestos traces should be removed, I cannot feel safe knowing that somewhere near me there are asbestos radiations, I cannot raise my children in such an environment. I want to get my house tested for asbestos, let's hope I won't need an asbestos lawyer after that.

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