Uncategorized

Key Takeaways

  • Insulation is roughly half the cost of a roofing system. That share is what makes R-value changes a budget event rather than a technical footnote. KPost CEO Keith Post noted the value sitting at 20 with expectations it would climb to 30, and industry talk of 42, each step pushing system cost higher.
  • LTTR is a 15-year time-weighted average, not a fresh number. The ASTM C1289-13e1 standard took effect January 1, 2014 and established how Long-Term Thermal Resistance gets calculated for Polyiso, using consensus standards from the United States and Canada.
  • Before the standard, every manufacturer set its own specs. R-values varied by producer, which made products hard to compare on a bid. PIMA members adopted LTTR as the exclusive measure for permeable-faced Polyiso and submit to testing voluntarily, and non-members were expected to fall in line.
  • Thicker insulation raises costs beyond the insulation itself. Kelly Lea, KPost’s VP of Estimating, pointed out that any job not permitted before the change had to be rebid, and that thicker board also requires longer fasteners. The knock-on costs land in places a spreadsheet doesn’t anticipate.
  • Codes vary city by city, so bids need research. Senior estimator Aileen Struble noted that every city and county adopts building codes independently and not all sit at the latest standard. Lightweight insulating concrete typically runs about 30% less than a rigid Polyiso system, which makes it worth pricing as an alternative.

It might seem to the average person that the commercial roofing industry has not changed significantly over the last few years, but with the continued focus on green products and environmental impact, the roofing and construction industries have undergone many changes. One very important change is the ASTM C1289-13e1 standard for insulation testing that went into effect on January 1, 2014 providing new testing methods for the determination and calculation of Long-Term Thermal Resistance (LTTR) values for Polyiso roofing products.

Polyiso is a very popular roofing insulating product used in a large number of roofing systems. Recent changes of the LTTR values are based on consensus standards in the United States and Canada using a scientifically supported method to calculate the 15-year, time-weighted average R-value of roof insulation. What this means in plain English is that the insulation R-Value now has a standard, and that standard increases the amount of insulation across the board.

There are many manufacturers of Polyiso and all are required to comply with this new test standard, which is a major departure from the past, where every manufacturer had their own specifications. Those who are members of the Polyisocyanurate Insulation Manufacturers Association (PIMA) have adopted the LTTR method as the exclusive means to measure thermal performance of permeable-faced Polyiso roof insulation and voluntarily submit to testing. The others are expected to comply regardless.

So what does this mean for commercial roofing and building projects in 2014?

“Not only did the R-Value change level the playing field with regard to how manufacturers sell their products, but it also has a significant cost impact,” said Keith Post, KPost Company CEO. “In the past, the R-Values per manufacturer would vary. Now there is a standard. And that standard increases the amount of insulation required, which in turn increases the cost.”

Commercial Roofing and Construction Industry Impact

“This changes everything. We are talking about a fairly minor number, but it’s big enough to impact every bid,” said Kelly Lea, KPost Company Vice President of Estimating. “Any job that was not permitted in 2013 must be rebid with the new R-Value standard, which could impact the budget. As an example, the changing R-Values require thicker insulation which also increases the cost of a project in other ways, such as the need to use longer fasteners.”

Polyiso is in a large number of roofing systems, as it is the most common roofing insulation unless lightweight insulating concrete is installed. The cost of lightweight insulating concrete is typically 30% less expensive than rigid Polyiso roofing system

According to KPost Company senior estimator, Aileen Struble, R-Values are incredibly important from a budgeting and cost perspective, particularly in light of the fact that every city and county has its own building codes.

“As contractors, we are engaged in an endless learning process to be certain we are providing the correct product that meets the industry and city standards,” said Aileen. “Cities and counties can adopt building codes as they choose, and not all are up to the latest standard. It takes a lot of research to ensure the bids are in compliance with all the varying regulations and codes.”

According to Aileen, most cities and counties want to capitalize on tax advantages associated with utilizing green products to improve the environment. Therefore, they are becoming stricter about the types of construction products that can be used. Coupled with the recent R-Value change for Polyiso, the need to perform extensive research becomes paramount. Otherwise, the bid could be outdated before you even submit it.

“Roofing insulation already comprises approximately 50% of the overall cost of a roofing system. The R-Value is now at 20, but we know it will go up to 30. We’ve even heard it might increase to 42. Now the cost really starts to skyrocket,” said Keith. “We will have to research alternative coverings that are more durable and reflective in order to keep costs in check.”

How to Combat Cost Increases

Having the resources to stay on top of the industry changes makes a big difference in combating rising costs. For one, it ensures that the bid you receive contains the correct information while recommending the right product.

“KPost Company provides a consultative approach to our projects, so we are educating and informing along the way,” said Aileen. “Whether it’s the owner, property manager or contractor, we ensure that individual receives the right information while also providing educational materials. In addition, we approach each project from our customer’s perspective, so they receive more than one solution.”

In addition to ensuring the information is correct, there are alternatives to consider when recommending a roofing system.

“We invested in cellular lightweight insulating concrete several years ago because we could see the value it brings to our customers,” said Keith. “In addition to getting the same R-value as other products such as Polyiso, it lets us reuse the roof deck, making it environmentally friendly. Plus, it will provide a 20% savings, ensuring a solid cost savings.”

Whether it’s new construction or a reroofing project, confirming that you have the right information is critical to keeping costs in check and maintaining a budget. Fortunately, there are options to consider when determining the best commercial roofing system for your project. Bottom line – find a knowledgeable, educated contractor who stays on top of the industry changes and varying codes. That will save money, time and headaches on your next commercial roofing project.

FAQs

The requirement comes from the energy code adopted by your city, applied to the climate zone the Metroplex sits in, and it is expressed as a minimum R-value for insulation installed entirely above the deck. The figure has climbed through successive code cycles, so a roof built to code fifteen years ago is well below what a replacement must now meet. Because each city and county adopts codes independently and not all sit on the latest edition, confirm the requirement with the authority having jurisdiction for that specific address before pricing.

Polyiso has a thermal drift characteristic where its measured R-value declines as temperature drops, which is unusual among insulation types since most improve slightly in cold. The effect is modest at North Texas winter temperatures and matters far more in northern climates, but it is real, and it is one reason some designers specify a hybrid assembly pairing polyiso with a layer of a different material. It also explains why published values are given as long-term time-weighted averages rather than as fresh numbers.

More than the insulation line on the estimate. Fasteners have to be longer to reach the deck through the added thickness. Roof drains and scuppers may need to be reset so the finished surface still drains to them. Curbs under rooftop equipment, parapet heights, door thresholds onto the roof, and flashing heights at walls can all need adjustment to maintain required clearances above the new surface. These knock-on items are a routine source of surprise on a reroof priced from the insulation alone.

A cover board is a thin, dense layer installed between the insulation and the membrane. It gives the membrane a firm substrate, spreads foot traffic and hail impact instead of letting it dent the insulation beneath, and improves the fire and wind performance of the assembly. Many manufacturers now require one for their longer warranty terms. It adds cost per square foot and it is one of the more defensible upgrades on a roof that will see rooftop traffic. Our lightweight insulating concrete services offer another route to slope and thermal performance where cover board economics do not work.

Sometimes, if it is dry, intact, still adequately attached, and the assembly will meet current code with whatever is added on top. Moisture is what usually rules it out, and it is verified by infrared survey and by core cuts rather than by looking at the surface. Reusing sound insulation and adding a new layer over it can save meaningfully on both material and disposal, but wet insulation left in place under a new membrane will defeat the entire project.

Insulation specification decisions get made on projects like this one, a TPO system at The Stack at Deep Ellum:

company icon