Thursday, March 9, 2017

Reflective Roof Coatings FAQs

Ever had questions about roof coatings?  Here are some answers from the Roof Coatings Manufacturers Association (RCMA):

 
 
 

Reflective Coatings FAQs

Why should I get my roof coated with a reflective coating?

Coating will extend the life of the roof, by reducing heat transfer into the building, decreasing thermal shock (thermal expansion and contraction of the roof membrane), and helping to mitigate leaks. Reflective coatings also can reduce heat energy costs and improve the aesthetics of the roof.

What kind of roofs can be coated?

Almost all types of roofs can be coated. Some examples include metal, spray polyurethane, single-ply, modified bitumen, Built-up roof (BUR) systems, etc. Without special treatments, ballasted and gravel surfaced membranes are not typically acceptable roof surfaces for coating membranes.

What types of reflective coatings are available in the market?

There are several types of reflective roof coatings that impart varied reflectance rates/ values. Typically, the reflective coatings are what are commonly referred to as white coatings and there are also aluminum coatings typically used with asphalt. Highly reflective white roof coatings are typically comprised of acrylics, urethanes, silicones, SBS, SEBS, and other types.

How is the coating applied?

The coating can be applied using spray, roller or brush.

Do I need a primer?

A primer is no substitute for thorough cleaning. However, sometimes primers are required, depending on substrate and type of coating. Refer to your coating manufacturer for specific requirements.

How much coating should be put on the roof?

This depends on the coating manufacturer and the project specifications. When in doubt, consult the coating manufacturer you are working with.

How do I prepare the roof surface for coating?

The roof must be thoroughly cleaned, and allowed to dry thoroughly. This is a critical step to ensure a successful coating application. Be careful not to damage the lap seams. Care should be taken when pressure washing not to disturb the integrity of the underlying roof membrane particularly where there are adhered seams. Refer to the specific coating manufacturer you are using for their specific requirements for roof preparation.

Should I coat a new roof or nearly new roof?

Yes, a new roof should be coated if the building owner wants to add a highly reflective roof coating to reduce energy costs. The buyer should be aware of any warranties provided for a new roof that may violate that warranty during the period it is in force via the use of a roof coating. This will extend the roof’s service life. A reflective roof coating will reduce the heat load on the roofing assembly.
 
 

What are the energy savings?

This depends on the geographic location, insulation, and cost of electricity. Lawrence Berkeley National Laboratory (LBNL), Oak Ridge National Laboratory (ORNL), National Roofing Contractors Association (NRCA), and several roofing material manufacturers have computer programs that can estimate the savings. A growing number of energy consultants are available to provide environmental regulation compliance information.

Will a reflective coating extend the life of my roof?

Yes. The coating becomes the first layer of UV and waterproofing protection for the roof, and helps reduce expansion and contraction (thermal shock) of the roof.

Are there any warranties available?

Yes. Coating manufacturers offer different types of warranties depending on your needs and applications.

How long will the coating last?

Based on long-term histories, typically the roof life of a properly applied roof coating can be extended up to 10 years or more. Performance can vary depending on type and conditions, as well as the coating film thickness.

Can the roof be recoated in the future?

Yes. As the coating wears away, additional coating can be applied. Most coatings systems are renewable and sustainable. Refer to the specific coating manufacturer you are using for their specific requirements on re-coating applications.

Do I need a contractor, or can I do it myself?

The coating can be applied by a properly trained building owner or by an experienced roof coatings applicator. However, a roofing contractor is strongly recommended if there are such issues as existing leaks, wet insulation, damaged deck, or manufacturers’ warranties.

Can a coating stand up in ponding water conditions?

That depends on the coating. All roofs should be designed and built to have positive drainage and not allow ponding water. Some coatings are designed to withstand ponding conditions; however, not all coatings will withstand these conditions. Check with your manufacturer to see if your coating can withstand ponding water conditions.

In what weather conditions can the coating be applied?

For water borne coatings, the ambient air temperature should be 50oF (10oC) and rising, with no rain for the next 24 hours. Solvent borne coatings can be applied in colder weather. As always, check with the coating manufacturer.

How long does the coating take to dry/cure?

That depends on many factors: air temperature, wind, roof surface temperature, relative humidity (water borne coatings) coating color and the type of coating applied. For example, some coatings are moisture cured and thus humidity assists in its curing process.
 
 

Can I coat a rusted metal roof?

Rusted metal roofs can be coated after the rust conditions have been addressed. If the roof is “white rust” (zinc or aluminum) it can be coated after cleaning. If the roof is “red rust” the rust must be removed or treated with a corrosion inhibiting primer. All rusted fasteners should be treated or replaced.

What is ENERGY STAR?

ENERGY STAR is a US Government sponsored program encouraging the use of energy efficient products. Roofing materials including coatings can qualify for ENERGY STAR if the coating meets specific solar reflectance minimum criteria.

What is the Cool Roof Rating Council (CRRC)?

The Cool Roof Rating Council (CRRC) is an independent, non-profit organization that maintains a third-party rating system for radiative properties of roof surfacing materials.

Is there a tax advantage or rebate program available?

Some states, municipalities and utilities have programs. Check with your coatings manufacturer for further information. As a membership benefit, RCMA provides maintains a database of current information on rebates and tax credits for installing reflective roofs. RCMA’s customized search tool can be used to find the most up-to-date listings of reflective roofing financial incentives available.
Roof coatings are typically classified as maintenance, and in many cases can be written off as such in the same calendar year in which the coating application is completed; check with your CFO for specific details on roof maintenance tax deductions.

How do I maintain the coating?

It is recommended that the roof, including the coating, be inspected semi-annually and after a major storm or high wind “event”. Additional coating may need to be applied to repair damage to the coating and underlying roofing substrate. Check with the manufacturer and/or warranty program requirements.

What are Solar Reflectance and Thermal Emittance?

Solar Reflectance is a measure of the ability of a material (roof coating) to reflect the sun’s radiation. Thermal Emittance is a measure of the material (roof coating) to release trapped heat back into the atmosphere.

Will the coating stop my leaks?

While coatings may potentially stop minor leaks, the roof should be properly repaired and dried prior to coating application. Coatings may be able to seal pinhole leaks, which are leaks not visible to the naked eye. If the roof is leaking, the roof leak will need to be identified and repaired prior to any recoating; do not expect the coating to find and seal the leaks.

Where do I find a contractor to coat my roof?

Check with the coating manufacturer who may be able to suggest applicators who have used their products and have familiarity with the application. Another option would be to interview contractors and ask specific questions about their proven ability to install roof coatings. Contractors affiliated with the National Roofing Contractors Association (NRCA) or local roofing contractor trade associations typically are more knowledgeable. Consult those groups’ websites for contractors.
 
Original article can be found here: https://www.roofcoatings.org/reflective-roof-coatings-institute/solar-reflective-coatings-faqs/

If you have a roof issue, we are the professional roofers you’ve been looking for.  We are honest and professional and take our jobs very seriously.  We look to provide you the customer service you don’t expect from our industry.
To set an appointment for someone to come and look at your roof problem, please call 480-284-7338 or click here.
The Roof Medics – Roof Repair and Roof Replacement Specialists – Residential & Commericial Licensed, Bonded, Insured  – AZ ROC CR42 License #256001
Serving Phoenix, Mesa, Gilbert, Chandler, Tempe, Scottsdale
 

Monday, March 6, 2017

The Importance of Roof Ventilation

 

This is a great article about roof ventilation found on the GAF website:

Poor Attic Ventilation Can Ruin Your Insulation, Destroy Your Shingles, And Potentially Raise Your Energy Bills!

Proper Attic Ventilation
Proper attic ventilation systems allow a continual flow of outside air through the attic, protecting the efficiency of the insulation and helping to lower temperatures in the living space.
It consists of a balance between air intake (at your eaves or soffits) and air exhaust (at or near your roof ridge).
The U.S. FHA (Federal Housing Administration) recommends a minimum of at least 1 square foot of attic ventilation (both intake and exhaust) for every 300 square feet of attic space. For example, if your attic is 900 square feet, you need a total of 3 square feet of ventilation. This amount should be divided equally between intake and exhaust ventilation (i.e., 1 1/2 feet of each) to insure proper air flow through the attic. To calculate the amount of ventilation you need for your home, visit GAF's Ventilation Calculator .
Why Take Risks?
Many homes in North America do not have proper attic ventilation. Why? Because most people are unaware that attic ventilation can impact the longevity of their entire home!--
In the summer, improper ventilation can cause attic heat to build in excess of 160°F. This super-heated air eventually penetrates the ceiling insulation into the living area below.
Types of damage that can result include:
  • Premature aging of your roofing system ("fried" shingles)
  • Warping, cracking, or breaking down of wood framing
  • Damage to siding, exterior or interior paint, and wallpaper
A properly ventilated attic can help reduce the load on your air conditioner by moving the super-heated air out of your attic before it builds up and causes damage. 

In the winter, various household appliances, bathtubs, showers, and cooking vapors can contribute to excess moisture build-up. Improperly ventilated attics will allow this moisture to collect and cling to the underside of the roof. The moisture will condense and fall, soaking the attic insulation and reducing its efficiency.
Additional structural damage can include:
  • Roof deck warping and rotting of the wood frame
  • Mildew growth
  • Buckling of shingles and felt
Finally, attics should be properly ventilated to help prevent ice dams in cold northern climates. During the winter, ice and snow on a roof will melt and run down the deck to the cooler eaves. This run-off can re-freeze, creating an ice dam that may force water back up under the shingles and leak into your home — causing hundreds or thousands of dollars of damage to your ceilings and walls. Adequate attic ventilation reduces the amount of initial melting that occurs on your roof, thereby reducing the chance that ice dams will form.
 
 
If you have a roof issue, we are the professional roofers you’ve been looking for.  We are honest and professional and take our jobs very seriously.  We look to provide you the customer service you don’t expect from our industry.
To set an appointment for someone to come and look at your roof problem, please call 480-284-7338 or click here.
The Roof Medics – Roof Repair and Roof Replacement Specialists – Residential & Commericial Licensed, Bonded, Insured  – AZ ROC CR42 License #256001
Serving Phoenix, Mesa, Gilbert, Chandler, Tempe, Scottsdale