Advice for painting a concrete floor in a movie theater
April 6, 2019 10:30 AM   Subscribe

I'm looking for a cost-effective way to paint a concrete floor in a movie theater. The current paint job is in bad condition.

I'm the new owner of an old, independent movie theater. From what I understand, the floor was last painted about five years ago, using an epoxy-based paint. I've also heard that the paint started chipping soon after the paint job was completed. As it stands now, the floor is ugly, with large bare spots (see this photo). When we clean the theater, we often end up dislodging big chunks of paint from the floor.

I want to repaint the floor, but I don't have a lot of money to spend. Also, it's not feasible to remove the seats, so we would not be able to use some kind of floor-scraping machine.

Our handyman recommended using a wire brush on a broom handle to scrape the existing paint, then washing the floor with an ammonia-based degreaser, and then painting it with a latex paint that's made for concrete floors. He was vague about the exact type/brand of paint. The strategy would be to paint the floor in sections, over the course of a few weeks, so that we wouldn't have to close the theater.

I'm looking for a second opinion from someone who has direct experience in this arena. I've done some Googling, but the number of options is a little overwhelming. Specific brand recommendations would be much appreciated.
posted by JD Sockinger to Home & Garden (8 answers total)
I am concerned about the idea of exposing patrons to the fumes of drying paint if you attempt to stay open. I think it would be better to remove the old paint over a period of time, then close for 3-4 days; on day 1, use the degreaser/cleaner, and on day 2 after it's thoroughly dry, apply the paint throughout. Re-open only once you can walk into the theatre, stay for 2 hours, and not find the odour objectionable. The last thing you want to do is have your new patrons put off by a bad smell. They'll likely forgive a peeling floor much more than they will something that will give them a headache.
posted by seanmpuckett at 10:38 AM on April 6, 2019 [11 favorites]

We painted the studio floors where I had a space. We used a fast drying latex from Home Depot, with some sprinkle on sparkle bits, white flecks that did a lot to visually even out inconsistancies in the surface. It dried in an hour. Later you sweep to get up extra bits that didn't stick to the paint. There was little smell it was easy. I recommend cleaning the floor before and getting up what is going to come up. This paint is easy to apply, and then reapply for touch up or high traffic areas. The speckle bits are random and so repairs and paint overs always match. The studio owner went with battleship gray with white specks. Art studios, it was so forgiving and cleanable, and also ignorable too.
posted by Oyéah at 11:04 AM on April 6, 2019 [2 favorites]

FYI if you purchase low- or no-VOC paint, there is little or no odor. VOCs are the ingredient in paint that is both very bad for the environment and also the cause of the smell.

Low- and no-VOC paint does cost more. But if using it allows you to keep the theater open for several days, it might be worth it.

Here is one no-VOC floor paint I found in 5 seconds of googling (Disclaimer: I don't know anything more about that particular paint, or about floor paints in general, than that).
posted by flug at 11:34 AM on April 6, 2019

I would use a scraper to remove loose bits, or it will peel again. Oyéah's response sounds good. I would do a section at a time, and I would everything possible to maximize ventilation to reduce smell and improve drying time.
posted by theora55 at 12:03 PM on April 6, 2019

another good idea would be to choose a colour that is closer to the colour of the actual concrete, so that if it starts chipping again, it will be way less visible because there will be less contrast between the painted and chipped areas. A nice dark grey would be a good choice.
posted by 5_13_23_42_69_666 at 1:17 PM on April 6, 2019 [2 favorites]

From the large chipping sections, it looks like the epoxy paint layer might be delaminating from the concrete floor. Delamination happens when there is a slick layer that prevents the top coat from adhering. My guess is that the concrete is waxed beneath the epoxy layer. Paint needs a rough, textured surface to adhere best. Make sure the concrete layer doesn't have a slick coat of wax, oil, or some other substance. Otherwise, whatever top coat of additional paint applied will also delaminate. Could also be temperature change differential between the concrete and the paint.
posted by effluvia at 1:59 PM on April 6, 2019

Seconding effluvia. An Epoxy paint shouldn't come up in chunks. So either it it's not an epoxy or the floor wasn't prepped properly. Besides a slick coating epoxy can be prevented from bonding properly if it is dusty. Your picture looks a lot like a polished or very well floated concrete floor. Coatings aren't going to stick to it very well at all.

At any rate if it was me I'd acid etch the concrete before applying a new coating (using a hydrocloric acid product). You'd also have to get the floor down to bare concrete otherwise whatever non epoxy concrete coating product you use will come up anywhere there is epoxy remaining. While a manual brush might work I'd probably attack the remaining paint with a cupped wire brush in a 7" angle grinder. (I'd bet someone makes a large floor polisher like machine to do this as well; it might be something you can rent).

Not being able to close the theatre is going to make this job infinitely harder. Would it be possible to close off (with ropes/plastic ?) a third of the theatre at a time (left/middle/right or top/middle/bottom)? Maybe on slow days doing a 1/3 every week? That way you could remove the seatsin that area, do proper prep, and then coat a large portion of the floor all at once.
posted by Mitheral at 7:54 PM on April 6, 2019

I used to work in a facility that had painted concrete floors where the paint was lifting due to moisture from dripping condensation. We would scrape the paint off the floor with the broad, flat style paint scraper during down times. It was equally deeply satisfying to get the paint up in large sheets and very frustrating when it was still too well adhered to scrape up at all. It also gave me a lot of time to contemplate why someone would paint a concrete floor to begin with, especially grey. Is a grey painted floor really that much nicer than a plain concrete floor? Unless there is some sort of safety issue, like the painted floor is more slip resistant than than the unpainted floor, I would leave it unpainted, because you are going to have to repeat this process again some point in the future.
posted by velocipedestrienne at 2:59 PM on April 8, 2019

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