Wood Technical Planning Documents

• To determine window opening size for typical installations, add 3/4" to frame width and height.
• For large windows, multiple windows, out-of-plumb openings, and/or in masonry construction, the need for additional jamb clearances should be reviewed.

Proper sealant placement is critical to window or door performance.

• When applying siding, brick veneer or other exterior finish material, leave adequate space between the unit frame and the exterior finish material for backer rod and sealant.
• Note: The sealant details shown are standard recommendations from the sealant industry. Contact your sealant supplier for recommendations and instruction for this or any other application.

In addition to the recommendations for punched openings, the greater width of horizontal ribbons often requires special head/jamb details, reinforcing mullions, expansion mullions, and subsills to resist wind loads, allow for construction tolerances, and provide adequate water management.

Subsill systems that weep incidental moisture to the exterior are recommended for water management in openings where the potential for water infiltration is increased and may not be adequately managed by the building weather barrier, flashings and drainage system.

Sample conditions include, but are not limited to:

• Increased level of exposure due to multi-story construction
• High weather exposure
• Recaulking would be difficult or unlikely
• Non-standard installation methods
• When there are multiple units joined within the opening

• For horizontal ribbons, expansion/control mullions are recommended every 20' maximum.
• Minimum 1/2" clearance is recommended at each jamb for openings greater than 10' in masonry openings.
• A variety of expansion mullion details are available.

In addition to the recommendations for punched openings, the greater height of vertical stacks often requires special detailing, reinforcing mullions, intermediate dead load support, and subsills to resist structural loads, allow for construction tolerances, and provide adequate water management.

Operable or fixed windows of the same width (4"-11" max) can be stacked vertically to a maximum height of 20' without intermediate support.

• When window opening height is 12' to 20', see typical head detail to accommodate discrepancies in construction, floor and ceiling deflection, growth of unit assemblies and expansion movement.
• Frame expanders can be trimmed in the field.
• Receptors can be used to receive and trim the outside edge of the frame expander.

• Intermediate dead load support is required for vertical stacks more than 20' in height.
• Many solutions are possible, including those shown.
• Recommendations on the Weight Limitations of Transoms over Doors Combinations Recommendations can be used as a guide for sizing dead load support.
• Check local code requirements when stacking windows past floor lines.

Subsill systems that weep incidental moisture to the exterior are recommended for water management in openings where the potential for water infiltration is increased and may not be adequately managed by the building weather barrier, flashings and drainage system.

Sample conditions include, but are not limited to:

• Increased level of exposure due to multi-story construction
• High weather exposure
• Recaulking would be difficult or unlikely
• Non-standard installation methods
• When there are multiple units joined within the opening

Storefronts and entrances include a combination of windows and doors that often require reinforcing mullions, expansion mullions, and subsills to resist wind loads while providing adequate water management.

Window walls may include a combination of windows and doors that require reinforcing mullions, expansion mullions, and subsills to resist wind loads while providing adequate water management.

Specific accessories and construction details must address the various conditions that are critical for the proper design of combinations of windows and doors such as

• Proper flashing
• Control joints to accommodate expansion and contraction
• Intermediate structural support
• Mullion reinforcing and its end anchorage to the rough opening
• Rough opening wall construction to accept loads transferred from window combination

Placing windows and doors in a combination creates joints or mullions that may need structural reinforcing. Spread mullions can also be utilized to achieve an aesthetic element. In order to ensure that a given combination will withstand the design pressure, use the reinforcing tables on the following pages. These tables are organized by joint type and assembly type (factory vs. non-factory assembled). Use the graphical representation of each joint type to determine which joint type(s) are contained within the combination. The reinforcing tables consider structural performance only. See the Size and Performance Data page within each product section for single unit performance class and grade ratings.

IMPORTANT: Determining and meeting the structural load requirements and design of the rough opening is the responsibility of the architect or engineer. Window and door frame systems are not designed to support additional elements or components of the building wall system.

Durable, Factory applied aluminum trim

• Prefinished with Pella's tough EnduraClad finish; matches Pella products
• Brickmould or 3-1/2" brickmould, 3-1/2" flat, Jefferson or Monroe profiles
• Several sill nose options
• Custom profiles available
• Designed for aluminum-clad wood windows and doors

Durable, snap-in trim that is adjustable to field conditions

• Prefinished; matches Pella products
• Provides the look of flat trim
• Aluminum brickmould can be attached to re-create the look of historical wood brickmould
• No metal brake required
• Cut-to-length kits, 96" or 144" lengths
• Available in widths from 1" to 6"
• Receptors are available to provide a finished edge

Field-cut, protected, reversible wood trim

• Primed and ready for site finishing
• Grained or smooth appearance
• 10' lengths
• 3-1/2" or 5" flat widths, 3/4" thickness

Wood brickmould available factory-applied or in lineal lengths

• Available in primed Pine or Mahogany; ready for site finishing
• Straight or curved
• 1-7/8" or 3-1/2" brickmould or flat trim with 1-1/2" or 1-7/8" sill nose/subsill
• Standard and custom profiles available
• Designed for wood exterior windows and doors only

Durable, field-cut aluminum snap-in trim

• Prefinished; matches window frame
• 96" or 144" lengths
• 3" flat or 1-1/2" brickmould
• Custom brickmould profiles available
• Straight or curved

All profiles and accessories are available in Pine; select profiles and accessories are available in Oak. 34 unique profiles.

• Colonial - Simplicity and symmetry authentic to the traditional style. 13 profiles.
• Craftsman - Lasting influence and attention to detail mold the decorative features. 5 profiles.
• Provincial - Curved arches and soft lines create stylish effects from the simple to the extravagant. 9 profiles.
• Ranch - Smooth transitions and a long, low profile highlight the style options. 7 profiles.

Coordinate accessory trim to accents in the home with these beautiful choices.

• Stops
• Lattices
• Stools
• Quarter Rounds
• Trim

Applicable when the existing frames are in good condition and only the sash needs to be replaced.

• Fully assembled Precision Fit® double-hung, casement, awning and fixed windows
• Slides easily into existing pocket
• Trim, wall coverings, paint and plaster are usually not disturbed
• Reduces cost and inconvenience compared to a complete tear-out

Applicable when replacing wood windows.

• Aluminum subframe is preassembled and installed into openings
• Conceals existing wood window frame to become "receptor" for new window
• Allows installation from inside building
• Reduces labor costs and eliminates need for exterior scaffolding and its expense

Applicable when replacing metal windows.

• Aluminum subframe is preassembled and installed into openings
• Conceals existing wood window frame to become "receptor" for new window
• Allows installation from inside building
• Reduces labor costs and eliminates need for exterior scaffolding and its expense

Applicable when replacing wood or metal windows.

• Profile of subframe typically matches profile of existing window frame and brickmould
• Aluminum subframe is preassembled and installed into openings
• Conceals existing wood or metal window frame to become "receptor" for new window
• Allows installation from inside building
• Reduces labor costs and eliminates need for exterior scaffolding and its expense

Subframe expanders are used to expand the width of the subframe flange and are often used on curve-top window openings with rectangular windows.

When there are several window openings in a row, the mullion detail shown below can be used to enable the use of subframes in all of the openings while covering the exposed wood between subframes.

Aluminum brickmoulds can be added to the face of the subframe flange to match the profile of the historic wood brickmould.

• Field measurement guides are available for window replacement projects where only the window sashes are removed and the existing frame is left in place.
• These guides identify the important dimensions required to design the window replacement solution.
• Guides are available for existing wood and metal windows.