The Energy-Efficient Window Installation
Window installation with exterior insulation is a challenge. ThermalBuck solves the problems presented by “outsulation” by extending the mounting point for windows & doors to create a flush plane for cladding, and allows for structural attachment of the window.
It insulates the mounting points with an R-value of 4.4 – 17.6, and acts as an air & water barrier when installed with recommended sealants, preventing moisture around windows and doors.
Dimensionally stable, ThermalBuck won’t warp, shrink, or expand like a wooden buck. It prevents compression of rigid insulation, and helps to maintain the integrity of the window installation. Simple to install and easier to flash than a traditional wood buck, ThermalBuck is the continuous insulation solution.
Simple Installation Guide
MEASURE
Measure the Rough Opening. Allow 1/2″ additional room on all 4 sides (1″ overall) than recommended by window manufacturer. Check for level & plumb, shim interior if needed.
CUT
Inspect ThermalBuck for any damage. Angle cut pieces 45° with a miter saw. Undersize 1/16″ -1/8″ to allow for sealant at corners.
DRY-FIT
Dry-fit the pieces of ThermalBuck to ensure it fits properly, adjust as needed.
SEAL
Apply three 3/8″ bead of recommended sealant to the underside of each piece of ThermalBuck. Ensure 100% ooze-out at all transitions for complete air & water seal.
INSERT
Press ThermalBuck firmly into the rough opening along the total length to ensure a good seal. Start at the sill, then jambs & head.
SEAL
Add sealant to mitered ends before installing joining piece. Ensure 100% ooze-out at all transitions for a complete air & water seal at the rough opening. Add sealant if needed.
NAIL
Firmly hold ThermalBuck in place, and nail a 2″ roofing nail through the 1/2″ tongue, penetrating into the structure every 10″ – 12″. Add sealant to ends, then repeat steps for each jamb, and finish with head piece.
CLAMP
Align all 4 corners then clamp each with two roofing nails while the sealant cures (24 hours).
Do not install the window until the sealant has cured.
SMOOTH
Once 100% ooze-out is achieved, smooth sealant and remove excess.
INSTALL
Install window according to manufacturers’ instructions. Skip seal or do not seal the bottom flange for drainage.
Nails or screws must penetrate into the structure a minimum of 1-1/4″.
SEAL
Apply 3/8″ bead of sealant around the perimeter of all sides of ThermalBuck at the OSB transition to complete exterior air & water seal.
SEAL
Seal both the transition of ThermalBuck to the window and to the framing to complete the interior air & water seal, and create a back dam.
Detailed Installation: Self-Adhered WRB
These images provide a brief overview of ThermalBuck installation with a Self-Adhered WRB, which places the WRB against the sheathing and the continuous insulation (or rainscreen) as the final layer of the wall assembly. Download the complete photo guide to show every step along the way, and how to integrate the Self-Adhered WRB with ThermalBuck for a high-performance building envelope.
Dry-Fit the pieces of ThermalBuck, and ensure enough gap between mitered corners for sealant.
ThermalBuck has a waterproof coating, and all seams need to be sealed with approved window & door sealants.
The WRB goes under ThermalBuck at the sill, but wraps up against ThermalBuck at each jamb.
The window is fastened directly through ThermalBuck, and must penetrate 1-1/4″ minimum into the structure.
Download Installation Guide Self-Adhered WRB
Watch our Installation Videos for “on-site” help with each installation step
When installing a self-adhered membrane, first install the WRB, then tape back the head flap and jambs. Cut the WRB flush with RO at sill, and seal the WRB to sheathing at sill. This is the only place where the WRB will go between the ThermalBuck and the sheathing. Next, install ThermalBuck, then let cure for up to 24 hours. Install the window according to the manufacturer’s instructions. Seal the transition of ThermalBuck to the sheathing at the jambs with DAP Dynaflex 800 or Dow Corning 758, then press WRB into the wet sealant, to cover half the thickness of ThermalBuck. To complete flashing, tape across the jambs and head of WRB across nail flange of window. Install continuous insulation according to manufacturer’s instructions.
Note: consider WRB manufacturer’s recommendation for flashing tape. Download the full set of installation instructions with detailed photo steps.
Detailed Installation: WRB Interior to Continuous Insulation
These images provide a brief overview of the steps of the most common ThermalBuck installation, which places the WRB against the sheathing and the continuous insulation (or rainscreen) as the final layer of the wall assembly. Download the complete photo guide to show every step along the way, and how to integrate the WRB with ThermalBuck for a high-performance building envelope.
Download Installation Guide WRB Interior to CI
Watch our Installation Videos for “on-site” help with each installation step
When installing the WRB interior to the CI, first install the WRB, then tape back the head flap and jambs. Cut the WRB flush with RO at sill, and seal the WRB to sheathing at sill. This is the only place where the WRB will go between the ThermalBuck and the sheathing. Next, install ThermalBuck, then let cure for 24 hours. Install the window according to the manufacturer’s instructions. Seal the transition of ThermalBuck to the sheathing at the jambs and head with DAP Dynaflex 800 or Dow Corning 758, then press WRB into the wet sealant. To complete flashing, tape across the jambs and head of WRB across nail flange of window. Install continuous insulation according to manufacturer’s instructions.
Note: consider WRB manufacturer’s recommendation for flashing tape. Download the full set of installation instructions with detailed photo steps.
Detailed Installation: WRB Exterior to Continuous Insulation
These images provide a brief overview of the steps – which start with the Simple ThermalBuck Installation Guide. The continuous insulation is next, followed by the WRB. Download the complete photo guide to show every step along the way, and how to integrate the WRB with ThermalBuck for a high-performance building envelope.
Download Installation Guide WRB Exterior to CI
Watch our Installation Videos for “on-site” help with each installation step
When installing the WRB exterior to the exterior insulation, ThermalBuck is installed first using DAP Dynaflex 800 or Dow Corning 758 Sealant & nailed into the structure. (Note: sealant must cure for 24 hours before the window can be installed.) The exterior insulation is next, followed by the beginning of the WRB installation. Until the window is installed, the WRB can be completed only at the sill. Once the window installation is complete, then the head and jamb flaps of the WRB may be trimmed, sealed, and taped. Complete the flashing with tape across the nail flange of each jamb, and head flap of the WRB.
NOTE: Consider the WRB manufacturer’s recommendations for flashing tape. Download the full set of installation instructions with detailed photo steps.
Integrating the WRB & Continuous Insulation
ThermalBuck easily integrates with different wall assembly components, and each type of continuous insulation: Mineral Wool, EPS, XPS, and Polyiso. Take into consideration each of the product manufacturers’ installation instructions, and use best building practices for an air & water tight assembly. Here are just a few examples of the most common wall assemblies, and detailed installation instructions of how to integrate the WRB.
Watch our Installation Videos for “on-site” help with each installation step