Tiling Over Exterior Balconies and Decks - Risk or Reward?
In a seminar I attended recently hosted by the National Association of Home Builders, the speaker discussed at length the increasing trend of consumers to invest in elaborate exterior living spaces. Patios, decks, and balconies were specifically mentioned as areas that will take on increasing importance over the next several years. Our industry should realize this opportunity, but tread cautiously in regards to our approach.
As I write this article, I just got off of the telephone with one of my contractor members from the great state of Florida. I could feel his frustration through the line. “As contractors, we are being told so many different stories by the manufacturer, we don’t know whom to believe,” he said. “There are so many products out there advertising their system will work in exterior installations on balconies, we don’t know which way to turn.”
Often, when we receive a call pertaining to a balcony installation, we refer to the engineer or architect, to ensure the system they have specified can handle the weight of the assembly and that it is properly designed to prevent leaking. Too often it seems to me the tile contractor is left to make the decision regarding what membrane to use, how it is to be applied, and how to properly divert the water away from the structure. In Florida, where balcony installations are quite common, they receive over 50 inches of rainfall a year. This makes it imperative that these installations are designed and installed properly. There is no room for error. Failures in these types of installations can cost thousands, and even millions of dollars.
Common causes of failure include inadequate sub-floor strength to hold the weight of the assembly, improper drainage (industry standards call for 1/4 inch per foot), failure to properly waterproof the system, and incorrect flashing. There may be others but these are the most common.
Simply stated, the contractor has all the potential liability if they don’t make a good decision here. First, the balcony or roof deck should contain a detailed specification with plans and drawings. Without these plans, at a minimum, specific manufacturer instructions and warranty information needs to be supplied. This includes both the waterproofing and the thinset manufacturer, if they are not the same supplier.
So a contractor, when faced with these questions, should refer back to his manufacturer of choice on installation materials. Will the thinset manufacturer recommend their product to be applied to a roofing deck membrane? Lets let them make that decision. The same goes for the waterproof membrane, which must meet ANSI 118.10 requirements.
Another question we are often asked is whether ceramic tile can be applied to a wood deck system. Although currently there are no methods in the handbook for exterior wood decks, in certain situations you may find authorization to install ceramic tile on them. New products specifically designed for these applications could significantly impact this lucrative market. Stop to think for a minute how much ceramic tile we could sell and install on both new deck construction and existing deck remodeling or renovation.
It goes without saying that performance of a ceramic tile installation in an exterior environment begins first with the proper specification of the ceramic tile itself. The tile must be rated by the manufacturer to be suitable for an exterior installation. Certain slates and natural stones may work outside; others may not. Be sure to check the manufacturer recommendations always before going any further.
Contractors that embrace balcony and deck installations stand to pick up a lot of high profit work both now and in the future. But the work is at risk unless they take the necessary steps to ensure a successful installation. A proactive approach is to engage all the parties involved to map out a strategy of proper performance. If the architect/engineer, builder/general contractor, contractor/manufacturer all can agree on a method of installation that will withstand the test of time, success is likely to ensue.