The requirements when it comes to roofing insulation can vary quite a bit from state to state.  There are a variety of reasons why this is the case: the local climate—both natural and political—and the state’s commitment to energy efficiency are key among these.

When you move into a building, it’s important to keep it up to code and observe local requirements in order to avoid fines and fix-it orders. Of course, you don’t just want to keep your building compliant for legal reasons. Ensuring your home has the proper insulation will save you money on your energy bills and keep you comfortable during weather extremes.

Oregon, and the Pacific Northwest in general, is committed to environmentally friendly housing. The laws regarding this, however, can be a challenge to navigate. Below, we’ll tell you everything you need to know about Oregon insulation requirements.

Thermal envelope

As you read up on building codes and energy requirements, one phrase you’ll see pop up often is “thermal envelope.” This is an important one because it’s directly tied into your home’s energy efficiency.

The definition of thermal envelope is fairly straightforward. It’s simply the structure that separates the conditioned part of the home—essentially, everything inside—from the unconditioned part, which is the outside world, as well as other buildings. That means the thermal envelope of your home is essentially the combined product of your walls, doors, insulation, weather stripping, and perhaps most importantly, your roof and its insulation. Your thermal envelope is every part of your home that protects you from the elements.

A good quality thermal envelope means one that’s cool during the summer and warm during the winter. The most well-made and well-maintained homes have what is known as a “tight” thermal envelope, which allows for the movement of very little heat energy between the inside and the outside world. Over time, of course, the thermal envelope in a home will deteriorate. This will cause it to, ultimately, be less efficient and will drive your energy bill up.

Regular maintenance and care of all the parts of your home that make up its thermal envelope can help ensure your home remains energy-efficient for the long haul.

How your insulation affects this

Every part of your home contributes to a tight thermal envelope, but perhaps no single factor matters more than a well-maintained, well-insulated roof. After all, at the end of the day, it’s the roof that’s keeping the hot and damaging UV rays of the sun from reaching the rest of the house. It’s also the roof that’s your only line of defense against rain, hail, and snow.

A good roof is completely resistant to water and air leakage. If water gets in, it can wreak havoc on your home and damage a great deal of your personal property. If air leaks out, it will take heat energy with it, dramatically reducing the efficiency of your heater and air conditioner and driving your energy bill way up.

Both sunlight and water can do a number on the roof of your home, so you’ll regularly need to have it maintained by a trusted roofing contractor, such as Interstate Roofing. However, even if every shingle on the roof is perfectly placed and everything has been carefully sealed, heat can easily radiate in or out without proper insulation. In uninsulated buildings, more than 25 percent of heat energy can simply disappear, right through the roof.

That’s why you need to have some sort of barrier, and that’s what insulation is. It’s made from a material that can effectively slow the transfer of heat between your home and the outdoors. Common materials used for insulation are cellulose, fiberglass, and foam. These can be placed by your roofing contractor or a specialized insulation contractor, usually beneath the roof in an attic area of the home.

The law in Oregon

Owing to its ongoing commitment to energy efficiency and environmental protection, Oregon has somewhat tougher codes regarding roofing insulation than many other states. There are several codes in place to ensure homes, and other buildings, are as energy-efficient as possible in order to prevent burning fuel needlessly.

Perhaps the most important of these codes, where they apply to Oregon insulation requirements, is the 2018 International Energy Conservation Code (IECC). This and other codes governing the construction of buildings in Oregon are designed to ensure they’re more energy-efficient. When it comes to attic insulation, the primary element these codes will govern is the R-value of your insulation.

The R-value is simply the capacity of your insulation to resist the flow of heat. A higher R-value means a more efficiently insulated home. In Oregon, most residential homes are required to have an R-value of 38. This determines exactly how much insulation you need, depending upon what material your home is utilizing. For example, the R-value of cellulose insulation is about 3.5 per inch, so in order to reach 38, you’ll need more than 10 inches of material.  Fiberglass usually runs about the same, while foam can be a little less.

Note that other factors, besides the thickness of your insulation, can affect the R-value of your roof.  The R-value can also be reduced by moisture, temperature extremes, and simply by normal wear and tear brought on by the passing of time.

Making sure you’re up to code

To ensure your roof is properly insulated, so that your building remains in compliance with local laws while also saving you a great deal of money on your energy bill, you’ll need the services of a good roofing contractor. In the Portland area, you can check out Interstate Roofing.  Specializing in both residential and commercial roofing, we offer repairs and maintenance, as well as the installation of new materials, using highly skilled roofers and an unwavering commitment to safety.