Carriage House Flooring | Dr. Ian O'Byrne

We recently moved to our new home, and as a result we have a lot of new projects to complete.

The home has a detached garage with a finished spare room on the second floor. I’ll turn that spare room into my office and a room for friends and family to stay over. Apparently, I need to also start calling the structure a carriage house and not a garage…but that’s another topic entirely.

As we work through these projects, I’ll share some insight on the decisions, products, and processes to document my thinking. This may be of help to those of you that are also engaging in this work.

Carriage house

The second floor of the carriage house is finished. It has flooring. The walls are insulated, drywalled, and painted. There is even a full bath. The first floor is a typical garage. It has bare studs for the room…no insulation or drywall. The concrete floor is unfinished. The electrical system is minimal at best.

At some point, we will insulate and drywall the room. We’ll add more outlets and better lighting. I’d like the first floor to be more a space for a gym, gaming, and play. We didn’t have enough time to get in to complete the work on the wiring, insulation, and walls before moving. But, I decided to knock out the flooring quickly before we started loading stuff into the garage…carriage house.

Breathable epoxy floors

The flooring is typical, unfinished concrete slab. Most people would either leave the floor alone or put some sort of coating or covering to assist with traction or appearance.

We’ll use foam square padding to make it easier for working out or playing with the kids. I wanted an epoxy floor under the pads to seal the floor and make it look a bit more finished.

In a typical environment, I could purchase an epoxy floor kit from a big box store and install it myself. I’ve spent a couple of years working for my uncle and installing epoxy floors for high price clients. The challenge is that here in the lowcountry, we’re below sea level. Because there is naturally a lot of moisture under the concrete flooring, it will want to come up. Concrete, in and of itself is very breathable. That is to say that moisture can pass easily from the ground into the atmosphere.

The graphic below is meant to just illustrate that if I paint an impermeable membrane on top of the concrete, the moisture from the ground will continue to push up through the flooring. The moisture will ultimately win as the flooring will bubble, flake, crack and dissolve until the end of time.

The solution to this problem is the use of an epoxy floor that will allow the concrete to breathe. A covering that will be strong, yet also allow gases and moisture to freely pass.

I sketched out a schematic of the room in Google Keep for reference. Basically 20 by 24 feet for a total of 480 square feet.

Under the guidance of my uncle, I purchased four gallons of Armorseal 8100 from Sherwin Williams. This is a two part product. One gallon of part A is mixed with one quart of part B. You mix it thoroughly, let it sweat (activate) and then apply to the floors.

Preparation & application

As I’ve indicated, I’ve helped install several epoxy floors in my past. Even with this experience, I watched a bunch of YouTube videos to make sure I was successful. The Paint Life TV channel was an invaluable resource, and I followed the following process.

First, I degreased the floor using a giant barrel of Purple Power degreaser. I acid-etched the floor using muriatic acid, followed by scraping, and then another dose of muriatic acid. This was followed by a rinse with ammonia to neutralize the acid. Even though the floor was rinsed and appeared to be dry…the acid may still be in the pores of the concrete. I needed to neutralize it before moving on.

If this were a professional job, I would have ground down (sanded) the elevated parts and filled the cracks. Since it’s my garage…and I’ll have foam pads and other stuff in the garage…I scraped and sanded the extra paint and grime, but left the cracks alone.

I applied the first coat of epoxy once the floor was completely dry. This is a process as you’ll need to set up a station, mix the materials, and quickly get it on the floor and roll it out before it hardens. The epoxy is not cheap. If you don’t move quickly, you’ll get a hundred-dollar anchor to remember your efforts. I was thankful to have my son serve as an assistant in the process.

The first coat went down relatively well. One mistake was that I forgot to start the fan running on the other side of the room. The first coat looked good, but there were some uneven spots left in the application. The garage took three gallons of product.

The next day I swept everything out and floated a final coat using the last gallon of product.

In addition, I added some product to two pads of concrete that serve as an entryway to the carriage house and the back door. I’ll keep an eye on this to see how well it does in the elements.