Removing old underlay glued to screed floor in smokers flat

[Gossamer]

Evening,
I am refurbing a flat previously inhabited by a heavy smoker.
I removed the carpet and scraped the old underlay up, which was in an awful state.
I'm left with remnants of underlay which is stuck to the screed / concrete floor and stinks of smoke.
I need a 'blank canvas' before re carpeting as I don't want nicotine stains / smells coming through.
Any ideas?
Ta.

 

[foxhole]

Error 410 | Screwfix

Thousands of products at low trade prices | FREE next day delivery available | 30 day money back guarantee on all orders.

www.screwfix.com

 

[Gossamer]

Error 410 | Screwfix

Thousands of products at low trade prices | FREE next day delivery available | 30 day money back guarantee on all orders.

www.screwfix.com

Thanks but already scraped. Its the residual mess I need to get up.

 

[foxhole]

Try heating the blade before scraping

 

[Deleted member 174758]

A 1 to 2% solution of trisodoum phosphate (aka TSO, a heavy alkali once used in soap manufacture) in water will remove nocotine tar - crystals can be bought off Amazon. Alternatively, you could try a solution of caustic soda (often sold as a drain cleaner, bought as crystals), a very strong degreaser. Then scrape with a full size (i.e stand up) floor scraper whilst wet. Be cautious with these chemicals - always add the crystals to the water (NEVER the other way round) also that TSP is harmful to aquatic life and a splash of caustic in the eye can damage it - so glasses and rubber gloves at a times and windows open. I used TSP to clean off the paintwork of one flat we rented about 35 years back where the owner was a heavy smoker. Cured the problems after sugar soap had failed