Dodged a bullet with asbestos mastic under warped oak planks

Bought this 1920s bungalow last month and started pulling up the sagging hardwood in the living room after spotting black stains from a old leak. Turns out the boards were glued down with what looked like sketchy mastic, so i grabbed samples and sent em to a lab before sanding. Results came back clean--no asbestos, just some funky adhesive that softened with heat. Now im tackling the water rot by planing down the high spots and patching with new oak. Anyone dealt with similar surprises in vintage floors?

Smart move testing that mastic first. i skipped it once and ended up in respirators for a week.

For water damage, i always cut out the bad sections and sister em with fresh boards. Heat gun on the mastic makes scraping a breeze too.

We had a job like that in a 1930s place. Tested everything, only the backing paper had traces. Pro tip: use a wet vac nearby to keep dust down. Ended up with a beautiful refinish, client was stoked. But yeah, always demand the full lab report--some outfits just guess.

Lucky break. Our crew hit asbestos floor tiles last year, full abatement nightmare.

To remove mastic without chemicals, score it deep with a multi-tool then steam it off. Works on old glue like yours.

Nice save. I hate when water damage hides under layers--always check subfloor too.