Inadequate drainage can kill a roof quicker than fire or wind, but tapered systems can solve this potential problem–and many others:
Why spend the extra money on a tapered insulation system? Because it can probably save your new roof from an early demise.
Building owners and contractors who focus only on the initial cost of tapered insulation are overlooking the long range benefits and savings that such a system provides.
First of all, the inadequate drainage of a fiat roof can result in damage that is far more costly than installing tapered insulation in the first place.
Standing water will eventually cause serious damage to any portion of a building; but, because the progressive deterioration on a roof is not readily observable, building owners tend to dismiss the fact that water can cause far more destruction than fire or wind. Water damage is seldom covered by insurance or roofing guarantees.
Consider the fact that a one-inch deep pond of water weighs 5.2 pounds per square foot–a weight that many structures cannot withstand. Although in new construction, the designers may have figured this additional load into structural calculations, standing water still puts undo stress on the roof membrane.
In the case of an existing structure, both the building and the membrane may be at risk. Debris and sediment tend to accumulate in low lying ponds that sprout. plant life. The constant freezing and thawing of ponded water is yet another factor contributing to the breakdown of the existing roofing membrane.
Failure of any roofing membrane can lead to a variety of problems in the roof system and within the building as a whole. For example, wet insulation loses its ability to resist heat flow, leading to increased heating costs in the winter and cooling costs in the summer.
Leakage in one section of the roof system can eventually deteriorate the entire roof membrane; moisture can corrode metal decks, crack concrete decks and wet-rot wood decks. Finally, water-damaged building materials and furnishings can become quite costly to replace.
The tapered solution
The key to avoiding these expensive problems is to prevent them by providing adequate drainage. One of the most effective ways to do this is by using tapered insulation in both reroofing projects and in new construction. Understanding your insulation options allows you to choose a roofing system that is functional as well as economical over the entire life of the system.
The first consideration in choosing your tapered system should be to address your thermal requirements, The next step is to select a slope that will provide a constant decline to the drainage point. In so doing, local building codes, as well as surface irregularities, must be taken into account.
Tapers of 1/8 inch and 1/4 inch per foot have proven to be the most popular with building codes and specifiers. To compensate for any deflections on the deck, a minimum of 1/4 inch per foot slope seems to have become the norm. Tapered panels are also available in 1/16 inch, 3/16 inch, 3/8 inch, & 1/2 inch per foot slope.
Once the particular needs of the roof are established, the appropriate material can be specified. Any type of insulation that is available in flat boards can also be purchased in tapered form. Once you have examined the various types of insulation, you will be able to determine which one will provide optimal performance under your specific roofing circumstances,
In order to successfully complete a tapered project, it is imperative that the contractor, architect, and manufacturer clearly communicate with one another throughout the job in order to ensure that all aspects of the tapered design are consistent with roofing specifications and actual field conditions.
It is also important for contractors to familiarize themselves with the tapered system purchased because the panel sizes can vary from manufacturer to manufacturer.
Installation of a tapered system is not dramatically different from that of flat insulation with several key exceptions:
* After the delivery of the insulation has been verified on
the jobsite, it is important that the contractor separate each
different panel size into its own organized area. This practice
will allow the roofing contractor to quickly and easily find
the metal panels needed.
* Determine the area to be completed that day. Install the
board according to the code on the board corresponding to the
code that is shown on the shop drawing.
* Start boards either from the roof drain or the high point
depending on the tapered design being used.
Once properly installed, a tapered system will provide returns on the owner’s original investment.
Proper roof drainage will result in substantial savings from:
Reduced roof maintenance
Less stress to the building structure
Extended roof life
Consistent insulation performance
What’s more, the risk of disrupting building operations and damage to building contents will be dramatically reduced. Therefore, the cost of tapered insulation is not only justifiable but logical — from any angle.
Source: Copyright of RSI: Roofing, Siding, Insulation is the property of Questex Media Group