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

How it works

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

Installation Steps

ThermalBuck outperforms a traditional wood buck, and saves time on your window installation. 

ThermalBuck vs. wood

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

Thermal Bridge Coefficients

News & Events

Hands-On Building Science with Matt Risinger & ThermalBuck November 22, 2017

December 4, 2017 – Risinger & Co. Headquarters – Austin, TX Don’t Miss this Event! Risinger & Co. will present “Hands-On Building Science with ThermalBuck,” to the Austin green building community. You’ll see how easy it is to integrate ThermalBuck into a high-performance wall, to simplify the installation of windows… Read more

ThermalBuck Recognized as Energy-Efficient Technology by Window & Door Magazine November 20, 2017

ThermalBuck is proud to announce our inclusion in the Oct/Nov 2017 issue of Window & Door Magazine as part of the feature, “Energy Efficient Technology Showcase,” a collection of energy-efficient products for window and door dealers, as well as components for manufacturers. ThermalBuck is a high-performance window buck that extends and insulates the mounting point… Read more

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

High performance wall assemblies are becoming more common as builders work to make homes more energy-efficient, and meet energy code requirements. But builders know attaching windows with rigid foam or mineral wool isn’t easy.


ThermalBuck solves the challenge by extending the mounting point for windows & doors to create a flush plane for cladding. It 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. ThermalBuck saves both time and money when installing nail flange windows with continuous insulation – with more performance. 

*We recommend ThermalBuck installation with Dow Corning 758 Silicone Sealant or DAP Dynaflex 800 Modified Polymer Sealant.  

Insulates the rough opening to limit thermal bridging
Complete air & water barrier around windows & doors
Extends the mounting point to create a flush plane for cladding


ThermalBuck is the continuous insulation solution for the high-performance building envelope.


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.

Alpen Certified Installer attaching window into ThermalBuck


Simplify Window Installation

ThermalBuck solves multiple problems when using exterior insulation and/or rainscreens. It extends the mounting point of windows & doors to create a flush plane for cladding attachment. In addition, it allows for structural attachment to prevent the compression of insulation and preserve a tight wall assembly. 

Consult the window manufacturers’ recommendations, then add an additional 1/2″ on all 4 sides to accommodate ThermalBuck.  (see installation for example)

Side by side rough openings with ThermalBuck window buck installed shot from interior


Improve Performance and Efficiency

ThermalBuck simply does more than a wood window buck. It insulates the mounting points of windows & doors, and simplifies flashing. Dimensionally stable and strong, it helps to maintain the integrity of the window installation. ThermalBuck is part of a continuous insulation solution, and an essential part of the efficient building envelope. 

R-values range from 4.4 to 17.6. View the results of our thermal testing and see how ThermalBuck outperforms wood 2:1.  

Build Green and Live Green

Using ThermalBuck to improve your window installation means you’ll use fewer natural resources to heat and cool your home year-round. Not only will that save you money, it’s better for the environment too.  

ThermalBuck reduces thermal bridging and prevents moisture from accumulating, which improves your indoor air quality – and that benefits your family’s health.