Roof Talk-101 How Rainwater Catchment Can Help in Drought Areas

Roof Talk-101  

How Rainwater Catchment Can Help in Drought Areas

Martin Grohman

Did you know that one inch of rain falling on 1,000 square feet of a roof amounts to 640 gallons of water? That’s a significant amount of water—more than most households use in a day—and evidence of the fact that in a typical year (and in a temperate climate), thousands and thousands of gallons of available water are running off your roof.

The most common term for collecting water for household use these days is “rainwater catchment.” While still rare in the United States, it is quite common in other parts of the world, notably in the Caribbean. However, partly out of necessity and partly for reasons of conservation and sustainability, rainwater catchment is becoming more common in the United States.

Consider the fact that you’re watering your lawn and flushing your toilets with drinking water, and think about using rainwater for those times instead.

Rainwater catchment doesn’t have to be complex: you can start with a rain barrel and catch water for the lawn. More advanced systems incorporate a device called a first flush diverter. This diverts the rain that falls for the first few minutes away from your catchment system or barrels in order to “wash” the roof of pollen and other buildup that has accumulated since the last rain. From there, additional advances include filtration, treatment, and underground storage cisterns.

To really get where we need to be with rainwater catchment, significant plumbing work is required. That’s because separate systems for drinking water and rainwater would be needed for most homes. However, there has been some progress in this area, including the development of a standardized piping color (purple) for irrigation water.

Industrial users can benefit from rainwater catchment systems as well. A common use of rainwater is for cooling tower systems, which rely on evaporative cooling and thus require large amounts of makeup water to replace that which has evaporated. A rainwater catchment system on a large commercial roof paired with storage tanks—often mounted directly on the roof or sometimes buried under a parking lot—can easily supply this makeup water. And again, why use drinking water for this?

Have you experienced a water shortage in your area? Have you looked into rainwater catchment or other methods to use the roof as a water-savings asset? The day may come for more of the country as Net Zero homes also try to achieve Net Zero water.

ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .

Roof Talk-101 10 Reasons to Coat a Commercial Roof

Liza Barth

When assessing the condition of a commercial roof, it’s important to keep in mind that there are other options besides the typical repair or replace. In fact, coating may be the best choice. Here are some reasons to choose to coat a commercial roof instead of replacing or repairing it:

• The roof is sound, but needs reflectivity. As long as the current roof is sound with no wet insulation or active leaks, then coating can help. Coating extends the life of the roof membrane by protecting it from harmful UV rays that can cause “alligatoring,” as well as reducing heat that causes thermal expansion and contraction. Excessive thermal expansion and contraction can prematurely age the membrane, causing cracks, split seams, and blisters.
• To provide energy savings by reducing heat transfer into the building and therefore reducing air-conditioning costs. A dark roof can reach temperatures of over 150°F.  A cool roof could drop that temperature by 50°F or more.
• To help improve the inside comfort of the building especially with un-air- conditioned spaces.
• To improve the appearance of the existing roof by changing it to white or adding a color.
• To avoid inconveniencing tenants if the building is occupied. With a tear-off, tenants may need to relocate for a period of time or deal with noise, dust, and other issues that can affect their business productivity.
• To reduce the risk of exposing the roof. Coating does not require a tear-off and therefore does not expose the roof to the elements. If the roof already has up-to-code insulation, it’s not necessary to tear it off to bring the roof up to code.
• There is a tight budget. Coating can be a lower-cost choice while still giving the roof the proper protection it needs.
• There are many penetrations or equipment on the roof that would be difficult and costly to change, such as air-conditioning systems.
• There is a plan to sell the building in a few years. Coating is a good choice if an owner doesn’t want to invest much in the building, but still wants it to look better and extend the life of the roof until they sell.
• To simply add an additional level of protection from leaks.

Coating is a cost-effective solution to extend the life of the roof. Plus, there may be rebates and potential tax advantages since coatings are often considered a maintenance item. If you decide coating is right for your building, check with a certified contractor to properly evaluate your roof before doing any work.


ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .

Roof Talk-101 10 Common Commercial Roof Problems

Liza Barth

Problems on a roof can happen to any building, but most of the issues are largely preventable through planning. Several factors will influence a roof’s service life: design quality installation, products, maintenance, roof use, abuse, and weather. The 10 roof problems listed below are common occurrences, but through quality work and planning, most can be easily dealt with before a major, expensive problem occurs.

Problem #1: Roof leaks. With any type of roof, if it is leaking then you have a problem.

Solution: A proactive preventative maintenance program can eliminate or reduce building interior water intrusion.

Problem #2: Blow-offs, tenting, or billowing. This occurs if the roof is not adhered properly to the substrate. Single-ply roofs are at risk for blow-off and billowing.

Solution: Ask your roofing contractor to provide the proper specification or building code for your area when installing a new roof.

Problem #3: Poor installation or workmanship. A faulty installation increases the likelihood of problems and reduces a roof system’s life expectancy. Workmanship tends to be one of the more common problems or reasons for problems down the road.

Solution: Ask your contractor for a checklist specific to the roof system that should be used for information-gathering (data-collecting) and reporting. Also ask about moisture surveys. Roofs with insulation should be surveyed prior to being overlayed via non-destructive methods. Have your contractor provide a written inspection report, complete with digital photos. Clear details on any structural changes or modifications to the roof surface should also be provided to you.

Problem #4: Lack of maintenance. There are many reasons not to neglect a roof, including financial and safety, but it’s important to have routine inspections done. Ponding water, a base flashing that is slipping, or pitch pockets that haven’t been filled are items that can be easily spotted and fixed.

Solution: To maximize roof service life, a proactive maintenance program should begin in year #1. If you wait too long to initiate the program, you will reduce the potential benefits.

Problem #5: Ponding water.The National Roofing Contractors Association (NRCA) has classified “undesirable” ponding water as standing for more than 48 hours, although ponding can pose a threat in even shorter time spans. A matter of “deep” concern in the roofing industry is the fact that a 1” deep pond weighs 5.2 lbs./square foot. The additional weight of the load may pose a threat to the structural integrity of the building, with a very real possibility of roof collapse in extreme cases.

Solution: Look into ways to address proper drainage on the roof by adding roof drains or using tapered roof insulation. Also, check the flashings, as they can be a source of leaks.

Problem #6: Punctures and the addition of penetrations. For those with single-ply roof systems, damage from foot traffic can be problematic.

Solution: Limit traffic and conduct cursory inspections after tradespeople have been on the roof.

Problem #7: Safety. Fires, odors, slips, and falls are common issues that occur on the roof.

Solution: Make sure you have all the proper personal protection equipment, such as safety glasses, approved footwear, and hard hats. You should also have a copy of all the MSDS information for all the products being installed on the roof.

Problem #8: Improper repairs. Using materials that are not intended for application on specific roof types can result in permanent damage.

Solution: Ask your roofing contractor if they are certified from the manufacturer to install and repair your roof.

Problem #9: Shrinkage. Single-ply roof types are unique. If you walk out onto an EPDM roof, one of the first things you’re going to look for is evidence of shrinkage. The two items most commonly seen are flashings pulling away from the wall or curb and crazing and cracking of uncured membrane, which is commonly used at perimeter and penetration flashings.

Solution: Make sure you’re conducting visual inspections. Some experts recommend a minimum of two per year (late fall and early spring)…certainly at least annually.

Problem #10: Blistering, ridging, splitting, and surface erosion. These issues are commonly found with BUR roof systems, but can also happen in some single-ply systems.

Solution: Do your homework and make sure you select a certified and licensed roofing contractor before selecting or installing your new roof.

ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .

Roof Talk-101  How Rising Demand Charges Make the Case for White Roofing

Thomas J Taylor, PhD

There has been much trade press the past year arguing how far south a black roof will yield energy savings. Their main point is that black roofing has a winter warming benefit. However, the winter sun in Chicago is not very warm, and many of the calculations assume that commercial buildings are heated with electricity, which is usually not the case.

So, what is the right roof color to help lower energy costs? Much of the modeling understates the case for white roofing, but electric demand charges are changing that perception, since they can increase an electric bill by three times. Whether you’re designing a building or managing a facility, it’s important to understand demand charges—and white roofing is one way to keep costs under control.

Utility companies have to worry about two things when supplying a region—how much power they have to supply each month or quarter, and how to manage peak demands. Think brownouts in California during a summer afternoon, when everyone’s air conditioning is cranked up. If a lot of power is used one hot afternoon in July, the electric company will charge at a higher rate all month long. They focus on the high demand charges that occur in a short period of time and will penalize a building owner for it.

I spoke to Andre Desjarlais, Building Science Research Group Leader, at Oak Ridge National Labs to see what this means for an actual electric bill. He described two customers—both with the same monthly power usage of 2,500 kWh, except one of them paid over three times more than the other. How is this possible? Let’s take a look at the math:

(Credit: Department of Energy)

Even though both customers used the same total power, Customer A used it within a short window of time and was charged $1,775. Customer B spread out their demand and paid just $515—a third as much.

Sounds convincing, but all bills aren’t that simple. In fact, they’re actually very complicated to figure out, since they often don’t even mention demand charges. Desjarlais provided an example of how this looks on a typical utility bill:

(Credit: Department of Energy)

Look closely at the “Time of Use Detail” section. There are three charges based on actual usage: peak, partial-peak, and off-peak times of the day. Below that is a similar set of charges based on the actual rate of use, where demand charges account for 45% of the total bill! This shows the importance of checking these charges, especially since they rise faster than base charges.

A Californian example by Desjarlais shows demand charges climbing up by 30% over three years:

(Credit: Department of Energy)

Demand charges are an electrical phenomenon, and will be largest during the summer months when AC usage is at its peak. However, there are ways an architect or building manager can combat these extra costs:

• Add additional insulation.   Since insulation saves on both summer and winter charges, it always generates an improvement, regardless of geography.
• White roofing can have its biggest impact in lowering peak demand and, therefore, in lowering demand charges. This is true even for well-insulated buildings.
• Time the start-up of load-intensive equipment (such as refrigerators and air conditioners) to prevent spikes, and of building energy management software to avoid simultaneous operation of HVAC units.
• Use a professionally installed cool, reflective roofs or roof coating to reduce a building’s cooling needs and demand charges.
• For the building designer: by lowering AC demand with white roofs, the unit can be downsized. This will lower demand charges even further and reduce upfront capital costs—a true win-win.

ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .

Roof Talk-101  How a Roof Can Help Save Homeowners Money

Liza Barth

The cost of heating and cooling a home has literally gone through the roof, but the right roof can promote energy efficiency in your home.

Cool roofs are designed to have greater reflectance than traditional shingles, which helps reduce the temperature in your attic.  According to the Cool Roof Rating Council, cool roofs may save homeowners an average of 7-15% of their total cooling costs.[1]  Cool Roofs also help reduce pollution and greenhouse gas emissions. When helping homeowners choose a cool roof, look for shingles rated by the Cool Roof Rating Council and  Energy Star®.

You should also consider a home’s insulation.  If a home’s roof is poorly insulated, the heat and air conditioning need to work harder to regulate the temperature inside the house. The more they work, the more money is spent each month on the utility bill.


ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .

Roof Talk-101  3 Types of Moisture in Low-Slope Roofing Systems

Thomas J Taylor, PhD

Roofing systems must be designed and installed to address the many sources of moisture that can affect a building. Roofing manufacturers can provide the materials with a range of properties and options for the roofing system designer, but because each building is unique the final responsibility for ensuring that moisture and condensation don’t cause problems lies with the architect, system designer, project engineer, and/or roofing system professional.

Several years ago, SPRI issued an advisory bulletin on moisture and its effect on roofing systems. Their classification of the types of situations leading to moisture build-up is a good way to think about the main scenarios. I’ve listed them here, along with some general roofing system guidelines that may be useful. Of course, these guidelines should be superseded by those of a professional roof system designer.

1. Buildings with Small Amounts of Occupancy-Generated Moisture

These are the most common situations, covering office, retail, and warehouse spaces, for example. Warm air migrates upward and carries moisture with it. In northern climates, regardless of the membrane type, condensation can occur between the membrane and the insulation. Here is what to do in this situation.

• Try to always use two layers of insulation with staggered joints. This helps prevent migration of warm, moist air up to the underside of the roof membrane. Warm air and moisture generally move upward, so drying out the roof system during warmer/sunnier days is a slow and difficult process. The goal should be to minimize or prevent condensation in the first place.
• If a single layer of insulation is used, install cover boards, especially a high-density polyiso board, and use staggered joints.
• If the membrane is to be fully adhered with a water-based adhesive, special care is needed to select the right one. Some have been shown to re-liquify in the presence of moisture. 

2. Buildings with Large Amounts of Occupancy-Generated Moisture

This category includes paper mills, laundries, buildings with indoor swimming pools, and the like. The building’s air handling and ventilation systems should be carefully specified to take into account the moisture loading. Also, the entire building envelope needs to be designed and constructed in such a way that damaging condensation and moisture build-up doesn’t occur. It is critical that a building science professional experienced in these types of building occupancy and designs be involved.

• Some approaches used by building design professionals for these buildings involve the use of air and vapor barriers. Care is needed to make sure these are applied properly and without any damage to their integrity. Pay particular attention to how they are terminated around the perimeters and at penetrations.
• Remember that roof membranes are essentially impermeable. An air and vapor barrier placed lower in the roof system can prevent any water that has managed to leak in from going elsewhere.

3. Construction–Related Moisture

Most construction practices release some amount of moisture into the building space. These can be as straightforward as drywall installation and painting although these are typically relatively short term. However, some practices can release large amounts of water over a considerable time frame into the building. Concrete slab floors have been a challenge to use with some flooring materials, and building design professionals have methods to cope with the moisture release.

Concrete roof decks can present a challenge for roof system designers especially in new construction. Regardless of the type of concrete, significant amounts of water remain after curing is completed.

• There is very little correlation between cure time and the amount of water remaining. Guidelines such as not closing up the system until a minimum of 30 days after pouring and forming are not particularly effective at reducing or eliminating issues.
• Concrete in new construction that appears to be dry rarely is. Water takes a long time to diffuse out of a four inch-thick slab. In fact, the NRCA no longer considers the “plastic sheet test” to be a viable indicator of concrete’s surface dryness. That test involved taping a plastic sheet to the surface and monitoring moisture under it.
• Many roof system designers require concrete decks be covered with a vapor barrier. As with buildings that have occupancy-generated moisture, care must be taken to ensure that these are specified and installed correctly. Roof membranes are essentially impermeable and any moisture that does get into the roof system will not have a path out.
• Adopt a “belt and suspenders” approach to the roofing system and make sure any vapor barrier is terminated around the perimeter and penetrations properly. To do this, use two layers of insulation with staggered joints. When installing a fully adhered membrane with a water-based adhesive, make sure the adhesive will not re-liquify in the presence of moisture.
• Make sure professionals who have experience with this type of construction are involved. These could include structural engineers, building science experts, and concrete suppliers.

The vast majority of roof systems give trouble-free performance for many years. When problems do occur within a few years of installation, it could be due to installation defects or moisture build-up. Roofing manufacturers try to provide a wide range of material choices so that the design professional can configure the optimum system for each building. The guidance offered here might help you to ask the right questions. However, to lower the risk of issues, make sure design professionals experienced with moisture and humidity in your region are involved.

ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .

Roof Talk-101  How to Help Homeowners Understand Ice Damming

Paulo Vieiradias

The cold winter season is the time when many homeowners see icicles hanging from their eaves and/or water coming in the house due to ice damming on the roof.

There are three main causes of ice damming:

• Poor insulation from a house ceiling. An attic with inadequate or deteriorated insulation can cause ice damming.
• Lack of ventilation. A house with proper ventilation allows the necessary cold air to mix and cool the hot air from the house, which slows the snow melting down.
• Leaking gaps between the living space and the attic. These spaces allow extra heat to “escape” into the attic, which warms the space and melts even more snow.

Snow on the roof will eventually melt, but if the heat from the house causes the snow closer to the roof to turn into water, then that water can either go down slowly to the gutter or travel under the shingles. There is no heat at the gutter, so snow will remain there, creating a barrier. The water that is moving down will hit that cold snow barrier and then freeze again. This creates a dam (ice damming), which will hold the remaining water on the roof.

Shingle roofs are designed to shed water; they cannot handle having it freestanding. That is why a good quality leak barrier is needed at the eaves. To help your homeowner understand the importance, you can perform a simple test with a bottle of water. This will show that every nail going through the leak barrier is automatically sealed.

The most important thing a contractor can do to help homeowners with ice dam problems is to first clean the snow off the roof (following strict safety rules) and then create exits for the trapped water.

In the long term, the contractor should:

• Seal the living space.
• Install adequate attic insulation.
• Make sure that the attic is properly ventilated.

Preventing ice dams and icicles may not be possible at all times, but these are measures that can be taken to help stop water from entering the house.

ROOFGUARD-LLC has been installing commercial roofing systems for over 30 years. We have the solutions you are looking for if you desire a new commercial roof or need a re-roof. ROOFGUARD-LLC only uses the best products and installation practices to insure you have a worry free commercial roof. For more information visit us at. www.roofguardtexas.com and we also invite you to Like Us on our Roofguardtexas Facebook Page .