What Are Construction Thermal Bridges in Buildings?

Do you have a random “cold spot” in your dining room or perhaps in an area where a sweater is always needed, no matter how high the thermostat is set?  Thermal bridges may be at play.

If you don’t work in or around construction, you may have never heard the term “thermal bridging”–but you’ve likely felt its effects. In a nutshell, it’s the movement of heat across an object that is more conductive than the materials around it.

Thermal bridging not only causes a loss of heat within the space, it can also cause the warm air inside to cool down. As we approach the coldest season of the year, this means higher utility costs and potentially uncomfortable shifts in temperature inside your home or building.

Keep reading to find out exactly how thermal bridging works and what you can do to stop it:

What is thermal bridging?

When heat attempts to escape a room, it follows the path of least resistance. Likewise, the same process occurs during the summer, only in reverse, allowing heat to enter your otherwise cool building.

Thermal bridging happens when a more conductive material allows an easy pathway for heat flow–usually where there is a break in (or penetration of) the insulation. Some common locations include:

  • The junctions between the wall and the floor, roof, or doors and windows.
  • The junction between the building and the deck or patio
  • Penetrations in the building envelope to include pipes or cables
  • Wood, steel, or concrete envelope components such as foundations, studs, and joists
  • Recessed lighting
  • Window and door frames
  • Areas with gaps in insulation

Impacts and risks assumed due to thermal bridging

What does all of this mean for you? In addition to poor climate control, there are several other lesser-known (but still serious) effects caused by thermal bridging.

Thermal bridges can increase the risk of condensation on internal surfaces, and also cause condensation within the walls.  Both can lead to mold growth, which in turn can cause unpleasant odors, poor air quality, and most importantly long-term health problems. Additionally, unchecked condensation may eventually cause rot and structural damage.

Thermal Bridging in windows

Thermal bridging can have a significant effect on the energy efficiency of windows. The frames and spacers are the primary culprits.  Spacers are the, typically metal, “strip” that goes between and separates the glass on double and triple pane windows.  Different materials have different conductivity and impact the performance of the windows differently.  Condensation on a double pane window is generally due to the spacers.

With retrofit situations, knowing exactly how old a window is, as well as the component materials, can provide you with a general idea of its efficacy. Unfortunately, if your windows are rather dated or just poorly made, it is nearly impossible to add thermal breaks into an existing framing system.

Issues with roofs and foundations

By their very nature, roofs and foundations present a large number of challenges in terms of maintaining a thermal boundary. Drains, vents, and holes for pipes and wires (amongst other things) create unavoidable penetrations in the building envelope and insulation. Heat transfers from the building into the ground or from the building into the air are often inevitable, though they can be minimized.

Strategies and methods to reduce thermal bridges in buildings

Bottom line? In new construction, design it right which a whole topic in itself. With existing homes, if you suspect there is thermal bridging occurring in your space, you need to eliminate or reduce the effects as much as possible.

Proper planning, design, and construction can help remedy thermal bridges in new structures. However, if you live in an older home, there are still steps you could take. These strategies include:

  • Performing an energy audit to identify thermal bridges in your home
  • Installing double or triple pane windows with argon or krypton gas, better spacers and insulated frames
  • Updating and/or adding insulation to your home – ideally adding a continuous insulation layer.
  • Installing storm doors (especially if you have metal doors)
  • The ultimate remedy is to complete a deep energy retrofit that addresses everything and more than mentioned in this blog

Studies show that in an otherwise airtight and insulated home, thermal bridges can account for a heat loss of up to 30%. Whether you’re building a new home or retrofitting an existing structure, care should be taken to avoid unnecessary breaks or penetrations so that the possibility of thermal bridging decreases.

If you’re looking for ways to minimize thermal bridges in your next project or existing home, contact us today.

Mineral Wool Insulation: The Naked Truth

Let’s face it. Life is hard.
Sometimes, pressures of work, family and bills can kick us in the teeth. And some days, we’re counting down the minutes to get home, kick off our shoes and chill. Maybe relax to some music or zone out with some Netflix. Better still, remove the confines of the day by removing our clothes – naked with no cares.

Reality, though, comes in the form of an uncomfortable and unhealthy home, as well as peeping Toms and unexpected visits from the in-laws. Just because you can relax in the raw, doesn’t mean you should!

As architects and builders, you may not be able give your clients peace of mind about walking around naked, but you can give them the comfortable sanctuary they crave in a cost-efficient home with clean air and ideal temperatures.

One excellent way to do just that is with mineral wool insulation, a building product made of rock that is heated and spun like cotton candy to create fibers, which are then put into batts and boards. It can be used in new construction or added to existing structures.

Environmentally friendly, it is composed of 85 percent recycled slag from the steel processing industry, and 15 percent raw basalt. Also, EPA testing confirms allergens and toxins are virtually non-existent.

That’s a major plus for all but especially for home owners with children.

Consider these additional, exceptional benefits of using mineral wool insulation:

Fire Resistance

The temperature range for house fires is 1200-1400 degrees F. Mineral wool insulation melts at 2150 degrees F. This means it will not catch fire. Because it is non-combustible, it doesn’t contribute to nor will it spread a fire. In addition, when heated it will not release toxic gases. Simply put, rock doesn’t burn. Designed to maintain its integrity when exposed to flames, mineral wool allows for escape in the event of a fire. Safety should be your number one concern for a client.

Sound Reduction

Mineral wool is an excellent acoustic insulation, because rock is a natural sound barrier. Due to its unique, non-directional structure, mineral wool is denser than conventional insulation and helps to absorb and minimize sound. Owners of concert halls and playhouses find it extremely effective for keeping sound within their buildings. On a smaller scale, your client will appreciate mineral wool keeping sound out for a quieter home. 

Rot Resistance

Mineral wool insulation is permeable, allowing water and vapors to escape. Also, it is somewhat water repellent. And because mineral wool has no food source, it cannot grow mildew, mold or any bacteria. This is good news, not only for those with allergies and health conditions but also for you, the builder or architect, because it helps prevent lawsuits due to wall construction failure. Vapor open assemblies, especially to the exterior, present fewer risks.

Longevity

Mineral wool insulation does not shrink, change shape or crumble – despite temperature changes or humidity. It is maintenance-free and needs no replacement.

Mineral wool perhaps is most celebrated for its thermal properties. Because it contains tiny pockets of air trapped within its physical structure, mineral wool provides extraordinary insulation, creating the down blanket for homes in cooler climates and keeping heat out of homes in warmer climates. The obvious benefit is a reduction of heating/cooling costs. Reduction in energy use plus lifelong durability equals savings in your clients’ pockets over the long-run.

Sustainability

Recycled slag and raw basalt is plentiful, and mineral wool is recyclable. Therefore, resources aren’t drained in the production of mineral wool insulation.

Also, the energy saved from the installation of mineral wood insulation far surpasses the energy spent for its production. The money spent is minimal when compared to the long-term benefits.

The above are all benefits for your client, but there are some serious benefits to you as well. When it comes to new construction and existing buildings, your reputation and business are on the line. Any faulty building product or choice of building assembly can put your insurance premiums at risk. As building codes become more stringent, and wall assemblies become more complex, mineral wool insulation reduces your liability.

Mineral wool insulation is a deal maker, not a deal breaker.

While your clients might or might not enjoy their home naked, you can have peace of mind knowing you’re providing them the comfort to do so.

For more information, contact AE Building Systems.
Source: Roxul.com