Basements (8 of 9): Floating Walls

Floating Wall Detail

“Floating walls” are not like “Sky-hooks”.  It is not an imaginary term used in jest to explain how a building will stand.  Floating walls are real and very necessary for basement finishing.  This simply means that the wall does not extend fully from floor to ceiling.  Don’t fret.  That doesn’t mean they are not solid or that they don’t provide separation from one room to the next.  There are two ways to construct a floating wall.  The most common and preferred method is to hang the wall from the ceiling, leaving a gap at the base to allow room for the concrete floor to heave if necessary.  As discussed in the previous post, treated wood is secured to the floor and a gap of about 1”-2” is provided above this.  The “floating wall” suspended from the ceiling is then secured laterally by tie rods into the base plate penetrating the floating base through a slip hole.  (See the detail for better clarification.)  This is preferred over another method of providing the gap at the top of the wall.  If the gap is at the top than any floor movement will result in cracks in the wall finish because floors do not heave evenly.  So remember, “floating walls = good”, “sky-hooks = bad”.

Basements (7 of 9): Exterior Walls

Most people, when finishing their basement, want to cover the exterior masonry walls.  After all, who wants to stare at a mass of rough, gray, cold wall?  Furring out the wall (built-out framing) will remedy this quite nicely, but before this is done one must verify that there is proper drainage at the base of the wall.  This is not easy to verify because the drainage is buried under several feet of dirt.  If you have a newer home you can check the plans on file or check with the original builder.  The reason you want to have proper perimeter drainage is because you will not be able to tell if there is water leaking through the wall once you have covered it up.  So, assuming you have proper drainage you have several ways to finish the walls.  One that is not recommended but seems to be popular with most do-it-yourselfers is to “glue” drywall to the surface of the concrete.  (Yikes!)  This is not recommended because any movement of the wall will result in cracks in the finished material, which inevitably results in pounds of mud (or drywall joint compound) being plastered over the crack over many years.  Another, only slightly better method, is to attach furring strips to the concrete and then secure gypsum board (drywall) to the furring strips.  A couple of flaws with this is that most do not think of providing treated wood (as discussed in an earlier post) and with the furring strips securely fastened to the concrete you still have the same issue of cracks due to any wall movement.  For the best results, use the floating wall method described in the previous post with an air gap of about one inch between framing and concrete.  This allows the wall and floor to move without interfering with any finishes.  The expense is a little more up front, but you don’t have to worry about trying to cover-up the mistakes of poor installation over the years with mounds of mud.

Basements (6 of 9): Treated Wood

Finishing your basement is more than throwing up walls and covering them with drywall.  What most people don’t realize is that wood has a chemical reaction when placed next to concrete.  This reaction deteriorates the wood in a short period of time and will create many unwanted issues.  Fortunately, we have become wise in some things and discovered that treating wood with certain chemicals will prevent these reactions, making it possible to use concrete and wood together to create lasting structures.  So, don’t be fooled by someone claiming they can finish your basement for you simply because they can swing a hammer.  You may find yourself with very costly repairs in the near future.

Basements (5 of 9): Plumbing

Most home builders have good intentions when they provide rough plumbing layouts in basements.  This is both good and bad.  It is good that you don’t have to put the expense of tearing up concrete to put in your own plumbing, etc.  Most fixtures have been considered and can be worked into the space they have provided.  However, this also limits the layout of the entire basement.  You have to put the bathroom right where they have chosen and hope you can be happy with the configuration of rooms that will fit around it.  Even the bathroom can only be configured the way the rough plumbing is laid out.  The location of the door is usually implied as well, so all areas are predesigned in a sense because of the plumbing configuration.  The savings of not having to put in your own plumbing, etc. could be worth the limited design potential.

If you don’t have rough plumbing provided, this too is a blessing and a curse.  If you are simply designing an additional living room there may not be a need for a bathroom or plumbing.  In most cases, if someone is planning to make use of their basement, they usually have additional bedrooms, fitness rooms, theaters or other spaces in mind.  For convenience (especially with bedrooms) providing a bathroom is essential.  This means you must cut through existing concrete (unless you are fortunate to have a framed floor over crawl space) and run new lines (supply and waste) to the new locations.  Most basements will have floor drains provided and the water heater is usually located in the basement.  This is an advantage which can be utilized, and if planning is done correctly near existing plumbing supply lines, the excavation, demolition and repair will be minimal.

So the long and short is that there are advantages and disadvantages to having or not having rough plumbing provided.  In either case, a good designer can take advantage of the situation and give you the best solution to fit your needs and the space provided.  Don’t be afraid to explore the options – paper is cheap – so find the design that you will love!