New carpet over black cutback?


  #1  
Old 02-11-03, 06:56 PM
tskoglund
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New carpet over black cutback?

My question is related to a previous thread about carpet installation over bad vinyl tile. The old tiles are 9"x9" (I think it's VAT) and were installed on the concrete slab using black cutback about 45 years ago. Now that I'm removing old carpet that was installed over the tile, so many of the vinyl tiles are coming up (about 1/3), that I'm thinking it would be easier to remove all the tiles rather than re-gluing all the loose ones.

However, the cutback is somewhat water soluble and I fear any future attempt to steam clean will draw some of the black cutback into the new pad (8lb and 3/8" or 1/2" thick) and carpet. Is this really a concern?

If so, is there some sort of sealer that I should coat over the cutback in lieu of regluing all the loose tiles? Thanks in advance.

(removing the cutback is NOT an option. I've already spent many hard hours doing just that to prepare for ceramic tile installation and there's no way I'm doing that again!)
 
  #2  
Old 02-11-03, 07:27 PM
FloorMagic
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Encapsulate

http://www.ardex.com/main-guidelines.htm#cutback

Cutback is nasty stuff and it used to contain asbestos. It's dangerous, don't fool with it.
 
  #3  
Old 02-11-03, 07:59 PM
tskoglund
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I read the link about dealing/not dealing with cutback, but I'm still not sure what the recommendation for my application is. I didn't see a specific ARDEX product for sealing the cutback and my installation is happening very soon, so I've got to find whatever I use locally. That, or glue the old tiles back down.

Any suggestions/recommendaitons?
 
  #4  
Old 02-11-03, 08:36 PM
FloorMagic
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http://www.ardex.com/prod-sdf-bro.htm

Ardex featherfinish will do the job. For your application any portland based cementious patching compound that you might find in your local home center will work as an encapsulator (cover) as well.

According to Federal laws and guidelines I can't give you advice to remove anything that may contain asbestos, even tile. Even though it's in a non friable condition and looks harmless, it can be very, very dangerous to remove if not done properly. Proper disposal is a major issue also. http://www.mesoinfo.com/

If you need it removed look up a licensed abatement contractor.
http://www.thebluebook.com/cl/all203.htm

Skim off (feather) the edge of the remaining tile. Cover the cutback with the patch and call your city to find out about safe disposal of the loose tile.

http://www.state.ma.us/dep/bwp/asbestos/96-012.htm
 
  #5  
Old 02-12-03, 05:53 AM
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Yes Ardex SD-F Feather finish.

But you need to scrape the cutback down to a fine film.
 
  #6  
Old 02-12-03, 05:33 PM
FloorMagic
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Unhappy Scraping

You think scraping is a good idea without explaining the technique to prevent the asbestos from becoming friable? That advice seems curt and a tad irresponsible.

This is a stretch-in installation and achieving a chemical bond between the skim and the concrete is really not necessary. A mechanical bond will do just fine as there is no need to scrape anything. Skim over the tileless areas with a 1/8" U notch trowel. Let dry then flat trowel the ridges in. This will successfully encapsulate the cutback and prevent bleed through. Troweling wet patch will prevent any asbestos from breaking loose and becoming airborne.
 
  #7  
Old 02-12-03, 09:59 PM
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>>>>>You think scraping is a good idea without explaining the
technique to prevent the asbestos from becoming friable?
That advice seems curt and a tad irresponsible.
 
  #8  
Old 02-12-03, 10:42 PM
tskoglund
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The nearest Ardex distributor from the Valley is in San Antonio, a mere 250 miles away. So I checked Home Depot and bought Armstrong S-184 Fast Setting Patch and Skim Coat for $13/25lb bag. The Ardex product seems to be a faster setting material, but otherwise they seem to be very similar products.

All the concern about cutback scraping is moot in my case since the original layer is very thin and unscrapable. I used a floor squeegee to spread water back and forth over the surface of the floor. Then shop vacuumed up the brown water. I put a skim coat of S-184 over that using a flat trowel. There's definitely a technique to be learned in troweling the stuff, so avoid my mistake and make a small batch (~5 lb) to figure out the technique first before you committ too much of the first batch to waste. I think the 1/8" u-trowel first coat and smooth trowel finish coat would help make for an easier installation but it would likely have taken more patch material.

I was forced to take up all the old tile and removed the old tackless strips to get the tile underneath them. I wore a single-piece nose and mouth respirator designed for organic vapors for an asbestos filter (it's what I had), opened some windows at the opposite end of the room and pointed a large 2' fan out the window for negative ventilation.

Before discovering the VAT and cutback asbestos issue, I had removed a bunch of tile before without any protection at all. At this point, all I can hope is that the hazard is minimal for a once-in-a-lifetime, non-occupational exposure. The warnings on flooring product packaging regarding cutback asbestos sounds quite scary, but perhaps it's more of a CYA note for pro's who work with the stuff on a regular basis. I don't know for sure and can't do anything about it now.
 
 

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