Hello,

We have a three season room that the previous owners (or maybe the previous, previous owners) installed carpeting into, back in the 80s/90s. We didn’t love the color and the smell we’d find if we left the room closed up for a few days. This summer we ripped it up and found tons of adhesive underneath. After a few hours of attempted scraping, we called in the pros to have it refinished.

In terms of the job, we asked about exposing some aggregate. The contractor warned us that it’s a total crapshoot when it comes to exposing aggregate on previously poured concrete. There was no guarantee on what they’d find after they started removing material. That said, when they started the process, we were overjoyed to see what was underneath. They spent two days taking off material and polishing. The last day they started mopping to prepare for sealing and we noticed lots of visible swirling and lines. They applied a sealer, and left. We’d hoped that after things dried, the markings would be less visible, but after two days while everything was lighter in color, the swirls were still pretty visible.

At first i thought the patterns were from the polishing machines, but after comparing photos of before and after, it’s clearly staining from the carpet adhesive.

They came back out and took a look and admitted they’d never seen staining so bad and didn’t have any recommendations aside from epoxying the floor. He mentioned they’d already taken off quite a bit of material and if they did any more, we run the risk of aggregate starting to come loose. They offered to strip the sealer, but warned us of the risks of stains from spills. We had them remove the sealer, and considered the job done for now. After reading up it seems like there are potential health risks due to exposure to silica dust.

Short term, we don’t use the room at all in the cold winter months here in the in the midwest, so we’re in no rush to solve this. Long term, the room still doesn’t see a ton of traffic, although we do spend more time in the room during the summer and I’m not sure what to do at this point. Obviously we’ll have some rugs and furniture down which will help hide it.

Worst case it seems like a pretty simple job to put down sealer in the spring ourselves. The concrete company said we might need a quick polishing pass to take off some material and “open up” the concrete to take the sealer.

Pics 1-3 are after fully drying, 4-6 are right after the sealer was applied, 7-9 are before the adhesive was removed.

My questions at this point are: 1. Are there any solutions to removing the adhesive stains from concrete? Chemical, mechanical, or otherwise? Should we search for another vendor? 2. Would leaving the concrete unsealed for a few months help reduce the visibility of the markings? 3. Are there real health risks to unsealed concrete in livable spaces? 4. Does the contractor seem to be correct in their assessments and recommendations (live with the stains or epoxy)?