Window installation with exterior insulation is a challenge. Solve the problem with ThermalBuck.

 : ThermalBuck in Three Minutes

ThermalBuck extends the mounting point for windows & doors, and insulates the rough opening to limit thermal bridging. 

Product Sizes & Dimensions

ThermalBuck outperforms a traditional wood buck, and protects the integrity of your window installation. 

Testing & Technical

PHIUS Verified Psi-Install Data:
Alpen 925 Zenith Nail Fin Installation
with ThermalBuck.

Thermal Bridge Coefficients

News & Events

BRINC Products Featured in GreenBuilt Home Tour July 2, 2020

The Illinois Green Alliance has announced that its 2020 GreenBuilt Home Tour is going virtual – and we’re a part of it! This year’s event features four unique online sessions that focus on 12 different green home projects across Illinois. Each online event has a theme: passive house design, all-electric… Read more

high performance building featuring ThermalBuck and Alpen windows
BRINC to Exhibit at Better Buildings in Vermont and Wisconsin January 15, 2020

The impact of non-profit organizations that promote energy-efficient building standards is growing. Some of the most successful outreach programs include regional events that bring together architects, builders, and high-performance building material experts facing the same set of climate considerations. This February and March, BRINC Building Products will be again be… Read more

If a window isn’t installed properly, it won’t matter how energy efficient it is.


Installing windows on a building with exterior insulation isn’t easy.

The window and the rigid foam or mineral wool need to line up on the same plane for good drainage, proper cladding attachment, and to prevent compression of the insulation. 

Rough openings have always been the weakest spot on any building for air and water infiltration, and “bumping” the window out only makes it more difficult to achieve a good air and water seal.

Traditionally a wood buck is built to extend the mounting point of the window to create a flush plane. But wood can rot, warp, and shrink over time. Wood is a poor insulator, allowing thermal bridging around each window and door. Not only does it reduce the energy efficiency of the building, it causes condensation to form, and potential damage from moisture – which can lead to extensive repairs.

The continuous insulation solution for the high-performance building envelope.


ThermalBuck solves the challenge of installing nail flange windows & doors with exterior insulation by extending the mounting point to create a flush plane for cladding. It also insulates the rough opening, limiting thermal bridging around windows & doors.

Coated with a waterproof resin and secured to the rough opening with an air & water barrier sealant* and nails, it’s simple to install and easier to flash than a wood buck. Dimensionally stable and strong, it will not warp, rot, or shrink, and helps to support the weight of the window. ThermalBuck outperforms a traditional wood buck, and protects the integrity of your window & door installation.

*We recommend ThermalBuck installation with tested & approved sealants  See our FAQ page under “Sealants” for more information 


Austin builder Matt Risinger features ThermalBuck on an episode or Risinger Goes Rogue

“Once you see it, you really understand the problem this solves for builders like me.”

  – Matt Risinger, builder, building science expert, Risinger & Co., Austin, TX

How to Install a Window with Exterior Insulation

For information about scheduling a ThermalBuck installation demo in your area email us:

ThermalBuck Goes Rogue with Matt Risinger

Matt Risinger is a well-known talent in the building industry. Not only for his fine craftsmanship as high-end home-builder Risinger Homes, but also as a building science expert and educator.

Based in Austin, Texas, Matt appears at building events and trade shows across the U.S., and creates easy-to-follow, real-world content from his construction sites (that’s a lot of fun to watch) for his avid followers on social media. 

Matt recently featured hosted a demo in Austin, “Hands-On Building Science: Window Installation with Exterior Insulation” featuring ThermalBuck on Risinger Goes Rogue, as a smart, simple solution to the challenges builders face when installing windows with continuous insulation.