Also called cold or heat bridges, thermal bridging is often responsible for up to 30% of heat loss in your home. You want to avoid its occurrence as much as possible to prevent high energy bills and discomfort. To detect and address thermal bridges, proper planning, design and construction are necessary. This is one reason you should hire skilled contractors for your home.
What Is Thermal Bridging?
Thermal bridging refers to the movement of heat through an object that’s more conductive than the materials around it. The conductive object makes a path of least resistance for heat. In homes and businesses, thermal bridging can result in significant energy loss, meaning higher heating and cooling costs. It occurs when there’s a gap or penetration in the building envelope, such as the insulation.
Extremely insulated and airtight houses are more prone to thermal bridging. Usually, this problem is caused by the intersection between the wall and floor, or the wall and roof. It can also develop in holes in the building envelope for pipes and cables as well as window and door reveals. Another place where thermal bridges can be found is in steel wall ties used in cavity walls and other masonry construction.
Classifications of Thermal Bridges
Repeating Thermal Bridges
This kind of thermal bridge follows a repeating pattern within a structure’s thermal envelope. Some examples of repeating thermal bridges include steel wall tiles used in masonry cavity wall construction and ceiling joists found in cold pitched roofs when insulating at ceiling level. While common, repeating thermal bridges can waste a significant amount of energy. They should be included in the U-value calculation and considered during the planning, designing and construction of a house.
Non-Repeating Thermal Bridges
You can find non-repeating thermal bridges where there is an interruption in the continuity of a structure’s thermal envelope. These occur intermittently when materials with varying conductivity meet to create part of the envelope. Most times, this type of thermal bridge occurs in loft hatches, reveals around windows and doors, and other openings in the thermal envelope.
Geometrical Thermal Bridges
The geometry of a building is what causes geometrical thermal bridges. Common examples include the corners of external walls, wall-to-floor and wall-to-roof junctions, and the joints between adjacent walls. You can minimize these thermal bridges by keeping your home’s overall design as simple as possible.
Why You Don’t Want Thermal Bridges in Your Home
Higher Energy Bills
The more thermal bridges occur in your home, the more energy is lost. As much as possible, you should design and construct your home according to thermal bridge-free design. When thermal bridges are not considered during your home’s construction, you can end up paying more to keep your home comfortable, making energy-efficient features useless. Your insulation should be designed and installed properly.
Airtight homes or properties with high insulation levels are more susceptible to the effects of thermal bridges. Around 30% or more of energy loss in a house is due to thermal bridging, defeating the benefits of insulation on a structure. In summer, thermal bridges contribute to heat gain and heat loss in winter.
A building or home with thermal bridges is more likely to experience condensation on internal surfaces. Thermal bridges can also cause interstitial condensation within walls and other components of your home. You should be warier of interstitial condensation as it’s not easily seen in the interior or exterior of a structure.
Condensation occurs when warm air touches a cold surface or vice versa. Mold is one of the negative effects of condensation. When not addressed, mold can spread around your home and put the health of your family at risk. You want to avoid condensation as much as possible as it can lead to other problems, such as poor indoor air quality, rot and structural damage.
How to Avoid Thermal Bridging
Fixing Moisture Buildup With Insulated Sheathing
Insulated sheathing minimizes thermal bridging as it completely covers your interior, including the framework and studs. Materials used as thermal barriers usually allow condensation within the walls of a house. This occurs due to increased humidity levels or temperature, and humidity differences between your exterior and interior. Insulated sheathing offers great resistance to air and moisture, helping cut down energy loss due to thermal bridging.
Invest in Rigid Insulation Panels
Installing rigid panels over your exterior will create continuous insulation and eliminate thermal transfer. Most of these panels can be easily installed over many types of siding or exterior cladding. When applied correctly, they can get rid of many causes of thermal bridging, no matter the type of siding installed over it.
Pay Attention to Your Windows and Doors
Breaks in the insulation in your home’s exterior is an invitation for thermal bridges. They are more likely to occur in your windows and doors. To break the bridges, you must take better care of your windows and doors. Make sure there are no gaps around openings to avoid air transfer. Doors must have insulated glass or foam core, and you can also install curtains or blinds to further reduce energy loss.
Choose the Right Continuous Insulation
The right continuous insulation will form a tight building envelope over your home, which can help prevent energy loss. When your home is sufficiently insulated through continuous insulation, you’ll notice a huge improvement in your comfort, and your home’s value will increase as well.
The best way to install a layer of continuous insulation is on the home’s exterior, under your new siding. Moreover, by adding insulation during your siding replacement, the appearance of your interior won’t be affected. Expanded polystyrene (EPS), extruded polystyrene (XPS) and graphite polystyrene (GPS) are the three main types of rigid insulation typically used to insulate a structure beneath the new siding. These three types of insulation come in varying energy efficiency levels. While you can purchase them in standard dimensions, they still offer different features and advantages.
Consider Insulated Vinyl Siding
Another option you should consider is insulated vinyl siding. It is standard vinyl siding with solid rigid-foam insulation. This kind of siding offers better resistance against warping and movement than standard vinyl siding as it seals the gaps behind the stepped profile of the siding. The insulation also makes the siding more firm so it appears and feels more solid.
Standardized testing discovered that insulated vinyl siding can help in reducing thermal bridging and can boost the airtightness of your home or building by 11%. Keep in mind that siding replacement can involve significant costs, so make sure to hire an experienced contractor for your project. Don’t forget to do your research, and obtain estimates, and it would help to hire a local company. Only choose a licensed contractor with relevant experience on your project.