Pacific Northwest Garage Floors are different! As well as having a Resinous Floor Coating company in the Pacific Northwest I also sell the coatings throughout the country. This is a real advantage to us because we get to see the problems, the advantages and the issues of floor coatings in more places than just here.
Concrete in the PNW is special. It’s hard, it’s dense and it’s wet. Let’s look at these individually.
Hardness. The concrete in the Pacific Northwest is generally harder than many other places in the country. There is a good reason for that. Concrete is made up of a combination of aggregate which is rocks and sand and Portland Cement which is the glue that holds it all together. In the PNW we use granite which is a quartz or silica-based rock. This rock has a Moh’s hardness scale of a 7. The scale only goes to 10 which is the hardness of diamond. This means it is really hard. The next reason we have hard concrete is that after the concrete is poured, we have low even temperatures during the first 28 days. Because of the this the water stays in the concrete and does not wick away during this time. In that 28 days the concrete becomes 99% cured. The water hydrating with the Portland Cement is what cures concrete. So, the less water that wicks away from heat the harder the concrete becomes. So, between the hard aggregates and the low even temperatures we get hard concrete here.
Density. Because of the same curing reason that we have hard concrete we also have dense concrete. Water and Portland Cement make crystals. The better the curing conditions, the larger the crystals. These crystals fill in the voids in the concrete which makes it denser.
Wetness. You may not have noticed but, every once in a while, it rains here. According to weather.com Seattle experiences 152 days of rain a year. Basically, that means it rains every other day. It usually doesn’t rain a lot every other day but it does rain. What that means for us is that the moisture falls out of the sky and it goes into the ground. Then that moisture moves up thru your concrete in the form of vapor and evaporates into the atmosphere.
In the next part in this series about Pacific Northwest Garage Floors we will look at how we treat this different concrete differently.