# Forum Home Renovation Flooring  Black tar under carpet underlay?

## freeman2015

Ripped out the old carpet. Some underlay seem to be stuck to concrete floor due to a layer of black tar. What is this for? And how do i prep the floor for laminate?

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## goldie1

How old is the house. Old lino tiles used to be glued down with a bitumen adhesive. Think from memory 
it was called black jack and contained asbestos so it could be from a previous flooring

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## woodbe

I think goldie1 is on the money. 
We recently had some old vinyl tiles removed by asbestos company, and they also removed as much of the blackjack as possible. They said it is possible that it wasn't blackjack but not worth the bother for testing, just took it all out.

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## freeman2015

Thanks everyone for your conments. Below are pics of the 3 rooms where the carpet underlay was stuck to concrete floor. 
Living area: carpet underlay appears to be rubber but has been glued down to floor. We were able to remove with a floor scraper but required elbow grease.  
Rear bedroom: only the underlay that was near the window was stuck to floor.    
Bedroom 3: rubber carpet underlay was easier to remove from floor but some kind of black substance which showed trowel marks were under the underlay

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## freeman2015

Do you think these were blackjack or something else? Why was he carpet underlay stuck to some areas of the house but not on all of them?

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## goldie1

Your house doesn't look old enough for black jack. It prob last used in the late 60s. Pic 3 looks like  
foam back carpet was previously installed. It had a black rubber backing which was glued to the floor 
and had to be scraped up. Pic 1 possibly the same. How old is your house

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## freeman2015

Thanks goldie1. What a relief. Asbestos scared me a bit as we have scraped the underlay off. 
My house was built un 83. 
I wonder why was the rubber backing glued down on some areas? Is it for damp proofing/moisture barrier?

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## pharmaboy2

Looks like normal underlay - goes like that after a few years especially if it's been wet - one of the reasons foam is better than rubber. It's a bitch to get off as well, I had the problem on a boat, took a day to remove a few square metres

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## goldie1

> Thanks goldie1. What a relief. Asbestos scared me a bit as we have scraped the underlay off. 
> My house was built un 83. 
> I wonder why was the rubber backing glued down on some areas? Is it for damp proofing/moisture barrier?

  Not blackjack if built in 83. Pic 3 looks like foam back carpet which was normally fully glued 
The other 2 as pharmaboy said would some times stick its self to the floor as it  
deteriorated  Get one of these to scrape it up. Scraper Floor Qep 8in Extend Floor&wall 10-296 | Bunnings Warehouse 
They work a treat

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## commodorenut

After learning about the ability of dry ice in making bitumen deadening far easier to remove from car body shells, I'd be willing to give some dry ice a go and see if it can make it brittle so you can chip it away in chunks.
The trick is to keep the dry ice in a plastic bag, so you can keep moving it around and get far more mileage out of it.

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