FAQ's

Evans Roofing Company is proud to have on staff key personnel who are known throughout the Roofing Industry for their experience and knowledge of roofing. Here are some frequently asked questions, with their responses:

When I went up onto my roof after a rainstorm, I noticed several areas where water ponds. Is this a concern?
The short answer is yes, it can be a concern. The longer answer relates to the question, “What can be done about it?” In an ideal world, there would be no water ponding on roofs. Unfortunately, we don’t live in such a world. Most flat roofs have water ponding conditions, to at least some extent. If the building is fairly new, it probably doesn’t have much of a problem. However, older buildings tend to settle. Plywood, rafters and other supports tend to sag over time. This can cause pockets of water ponding. Also, when buildings were built back in the 1960’s (or earlier), people weren’t paying as much attention to water ponding issues. Many old buildings were built with roofs that have poor slope. As a result, some old buildings have a lot of ponding water. Correcting the problem at this stage could be extremely expensive or (in some cases) impractical. When re-roofing is performed, the issue at hand is, “Is it worth spending a lot of money to correct the problem?” In many cases, the answer is no.

Water ponding that evaporates within 72 hours is generally not considered to be a major problem. Some Manufacturer’s and Consultants use 48 hours as the guideline. In most cases, water ponding doesn’t cause the roof leak (unless it’s very severe). What water ponding can do is to cause the surface of the roof to prematurely deteriorate. This is generally the case in cap sheet surfaced and coating surfaced roofs. It’s usually not a major issue with single ply roofs.

The costs to correct water ponding issues can vary dramatically. Sometimes new drains can be added in strategic locations. However, if water ponding occurs in numerous locations, this can become very expensive and is not a practical approach. In some cases, water ponding problems can be corrected by installing new tapered roof insulation. This could be a consideration when re-roofing is performed. However, it can be very expensive and can double the cost of re-roofing.

The best way to analyze water ponding conditions is to have Evans Roofing Company inspect your roof. Our experts can give you an honest, accurate opinion as to what would be the best solution. If correcting water ponding issues makes sense, we’ll let you know. If it’s not cost effective to do, we’ll let you know that too! We look out for your best interests and can help you to make the right decision.
I would like to put Composition Shingles on my roof, but it’s not very steep. Is this a problem?
Yes, it can be a problem. Composition Shingles should not be installed when the roof slope is less than two (2) inches vertically to every twelve (12) inches horizontally. If the roof slope is less than that, composition shingles would not meet Building Code or Manufacturer requirements.
I have an old flat roof. How long do they normally last?
Most flat roofs in California are “Built-up Roofs” with either cap sheet or gravel surfacing. The anticipated life span of this type of roof can vary, depending upon the roof slope, quality of the roof system and the amount of roof equipment. However, the general average is usually within the fifteen (15) to twenty (20) year range.
I’ve heard that in California you must now install roof insulation when you replace an existing roof. Is this true?
The “Title 24 Building Energy Efficiency Standards” in the State of California changed on January 1, 2010. It is now mandatory in California that existing roofs comply with the requirements of these Standards when they are replaced, recovered or recoated. One of the critical changes to Title 24 is that roof insulation is now required when existing roofs are removed down to the roof deck or to down to recover boards. This requirement applies to nonresidential buildings, high-rise residential buildings, hotels and motels. It only applies to areas that are heated or air conditioned. The amount of required insulation varies, depending upon the building type and the geographical location. There are some exceptions (mainly for Historic Buildings). The new Title 24 requirements are very complicated and difficult for the average person to understand. Evans Roofing Company can help. If you have questions related to this topic, let us know. For more information on Title 24, click here.
What’s the best type of flat roof to install on a building?
There are several different types of roof systems that are designed for low-sloped (flat) roofs. Evans Roofing Company installs them all. They each have their own advantages and disadvantages. The most important thing is to match the right type of roof system to your building. This is where Evans Roofing Company can help. We analyze the design of the building, the use of the building and your specific requirements. We then recommend the type of system that’s right for you. For more information on types of roof systems, click here.
I own a commercial building that has had an ongoing leak problem. The roofer tells me that an air conditioning unit is causing the problem. My Air Conditioning Contractor tells me that it’s a roof problem. Who do I believe?
This has been an ongoing problem ever since they started installing air conditioning equipment (HVAC) on the tops of roofs. The answer is: “Sometimes the roof is the problem and sometimes the HVAC units are the problem”.

Air conditioning contractors are experts in what they do…..keep the interior of the building heated and/or cooled. Evans Roofing Company is an expert in leak detection. For almost thirty years we have investigated the source of thousands of these specific leaks. During that time, we’ve conducted water tests and have taken apart many different types of HVAC units. What we’ve discovered is that very often, what people think are roof leaks, are indeed HVAC leaks.

There are typically three main types of HVAC leaks:

HVAC Condensation Pan Leaks:
When air conditioning units operate, they collect condensation. HVAC units typically have internal sheet metal pans that collect and drain off the condensation water. Because this is a continuing process, the sheet metal pans have a tendency to rust out. When this happens, the water inside the HVAC unit can leak into the building. This is a common source of leakage, particularly in older units. It represents a significant percentage of the reported leak calls that we receive. If you experience ”roof leaks” when it’s not raining, the chances are that it’s an air conditioning problem.

HVAC Air Duct Leaks:
Sometimes HVAC units have sheet metal air ducts that run across the roof. These ducts have overlap seams, where they are connected together. These seams are sealed to prevent air from leaking in and out. But, they are also sealed to prevent water from getting inside. Unfortunately these seals can crack and wear out. When the HVAC units operate, a high vacuum occurs in some of the ducts. If the duct seals are cracked or broken, the vacuum can pull rain water inside. Once inside the ducts, the water can be blown through the system. If you experience leakage that is seen directly below air ducts or ceiling air vent openings, the chances are that this is the problem.

Vacuum induced Equipment Leakage:
Most HVAC units create significant interior vacuum. If there is a small hole or opening in the HVAC unit, the vacuum can pull rain water inside the unit. Sometimes roof leakage occurs on brand new roof systems directly underneath HVAC units. When this happens, we conduct intensive water tests, to determine the source of the problem. In many cases we find that the roof is not leaking. The HVAC unit is leaking internally.

A thorough investigation of this situation was conducted by the Steve Mandzik of the Irvine Company. Click here to view videos taken by Steve. Each video takes about three to five minutes to download. But, the videos present solid proof that some HVAC units leak internally. The water tests were performed on a sunny day on a roof that was completely dry.
I received a roofing proposal from someone who said he is a Licensed Roofing Contractor. How can I verify this?
Don’t take the Roofing Contractor’s word for it! Written documentation can be forged. Licenses can be revoked by the State. Insurance policies can be cancelled. The best way to be sure that everything is in order is to check with the California State License Board. It’s very simple to do. Just go onto the Contractor’s State License Board’s website at https://www2.cslb.ca.gov/OnlineServices/CheckLicense/LicenseRequest.asp and enter the Contractor’s name or license number. The website lists several different ways to search for the requested information. You should be able to find key information about the contractor. If the Contractor’s name is not listed on the website, use caution. The website also lists information about Workers Compensation Insurance. Check to see if the website indicates that they are exempt from Workers Compensation because they have no employees. If this is the case, and they actually do have employees, don’t let any of them onto your property. If they have an accident, you could be liable.