Before you can install a ceramic tile or stone floor, you need to know if the subfloor is even capable of supporting tile. Simply put, tiles can be a durable, low maintenance, beautiful floor choice…if it’s on a solid substrate. On the other hand,it can be an expensive mistake that cracks, breaks and requires multiple repairs that may never work if the subfloor is not prepared correctly. What factors do you need to look out for to decide if tile is right for your project, and what steps can be taken to insure a trouble free installation? for more related information, click here.
For tile to be successful, it needs rigid support, with very little tolerance for movement. The more rigid the substrate, the better chance the tile has of remaining crack free throughout its life. Most problems with tile floors over wood come from excessive ‘bounciness’ of the substrate. Carpet can handle some bending, vinyl tile can flex and bend a bit, hardwood floors can bend a little too, but if tile or stone is subjected to forces that push in 2 different directions at once, it doesn’t know how to bend. Instead, it cracks, first in the grout and then in the body of the tile. Consumers who have just paid thousands of dollars for a tile floor do not find these cracks appealing, to say the least. for further details, visit : http://www.gsa.gov/portal/content/113454
Realistically, if all of this flooring is hidden by finished ceilings below and covered over by old flooring layers above, educated guessing takes center stage. The following questions help to determine floor stiffness using common sense guidelines:
- What floor covering was on the floor before? If it had ceramic tile or stone, and the floor received reasonable traffic for years with no cracking or broken grout, it’s a pretty good bet that the subfloor is up to the job. If it was vinyl, carpet or hardwood, we are still in the dark.
- Does the floor feel bouncy? If so, it is. Trust your instincts. It’s not ready for tile. A well-built subfloor feels very stiff underfoot. Squeaking can also be a bad sign, but it may also solvable by screwing down the planks or plywood better into the joists.
- How thick is the subfloor and what is it made of? In new construction, ¾ inch plywood or Oriented Strand Board is a standard subfloor over joists that are 16 inches on center apart. We find that is almost never enough to meet the deflection standards in most homes. Other times there is old plank flooring beneath a layer of plywood. This is a wild card, since the engineering tables usually don’t include the value for planks in their calculation, but common sense says it does add some stiffness.
- How tough is the tile to be installed? Fairly thick quarry tiles, for example, may be rated for heavy duty industrial applications, although they are often installed in homes. Because they are thicker than normal tiles and able to withstand heavy traffic, they may be less prone to cracking than a sensitive, thinner tile. For that matter, natural stone such as marble and granite are on the other end of the spectrum – they crack even easier than ceramic tile and should not be used in settings where any excess deflection is possible. Intuition may tell you they are stronger than ceramic, but in fact they are more brittle and prone to cracking. They need twice as rigid a floor as ceramic.
- What condition does the wood appear to be in? Even if the amount of wood support seems adequate according to the tables, if it appears to have been water damaged, if sections of it look moldy or corroded due to rot or decay, it’s not doing its job. Options include replacing or reinforcing it, but not just ignoring it. Also, has it been cut into in various spots, such as a plumber cutting sections of the joists for positioning pipes? All of these problems can make the wood less effective.
If a subfloor displays excessive deflection, it can usually be remedied by installing more plywood on top of it before tile is laid, and by reinforcing the joists from below. While it may make the floor higher than before, think of it as a sort of ‘insurance policy‘ against flooring failure.