Here is Colorado, if you want to finish your basement, you have to construct floating walls. What exactly is a floating wall and why do you have to build one?
The reason you have to build floating walls in Colorado is due to the soil. We have what are called expansive soils, in that the clay will expand when/if it gets wet. This can cause the concrete floor of the basement to heave an inch or two. While that doesn’t sound like much, it’s enough to cause some serious problems if you don’t take it into consideration. Imagine your concrete floor rising 2 inches, then also lifting the first floor of your house. Bad news.
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Building a floating wall is really quite simple.
- Lay a 2×4 on the ground where you want to build a wall. This is called the bottom base plate. Attach it to the concrete floor using liquid nails (or some equivalent) and concrete nails. Concrete nails are driven through the 2×4 into the concrete floor using a .22 caliber ammunition.
- Lay another 2×4 on top of the base plate. This is called the top base plate. Cut yourself 3 or 4 pieces of wood that are 1.5 inches thick, but less than 3 inches thick. These will be temporary spacers between the bottom base plate and the top base plate.
- Drill a pilot hole every 36 inches along the top base plate. Square the bottom and top base plates. Then, drive a 60d nail through the pilot hole through the top base plate and into the bottom base plate.
- Run your 2×4 studs to the ceiling. Leave the spacers between the two plates until you finish building up the studs. This will stop the top base plate from pushing down.
- Once you finish building the wall, remove the temporary spacers. You now have a floating wall (you can also think of it as a hanging wall). As you will see, nothing is attached to the bottom base plate except the 60d nail. It will act as a guide rod should the floor start to rise. However, it will not lift the top base plate.
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