Introduction
Brick molding, also spelled brickmould, is exterior casing fitted around the outside edge of a door or window frame. Despite its name, it is not made from brick. It covers the frame-to-wall transition and provides a finished exterior edge. It may be used beside brick veneer, siding, stucco, or other cladding, and it is commonly supplied with some prehung exterior door systems.
What is Brick Molding and Its Purpose?
Brick molding is exterior trim, not the structural opening or the complete weatherproofing system. A door or window may instead use an integral flange, nailing fin, separate casing, or a masonry- or stucco-specific accessory. Identify the exact unit and its installation instructions before selecting replacement trim. Therma-Tru’s glossary defines brickmould as exterior trim around a door frame.
Properly detailed brick molding can:
- Cover the visible frame-to-wall transition and create a finished visual edge.
- Provide a surface for sealant joints where the door, window, or wall system specifies them.
- Help protect exposed frame edges only when the trim finish, flashing, drainage details, and maintenance are sound.
- Provide a mounting surface for an accessory only when the accessory manufacturer specifies that use and solid backing supports the fasteners.
Brick molding does not replace sound framing, a sill pan, head and jamb flashing, the weather-resistive barrier (WRB), or the wall drainage plane. Properly sealed joints may reduce localized air leakage, but any energy benefit depends on the complete installation: fastening, shimming, insulation, weatherstripping, flashing, and the wall air-control layer.
How Brick Molding Fits Into the Opening System
Use this simplified exterior-opening cross-section to separate trim from water management. The exact order and materials are manufacturer- and wall-system-specific.
- Door or window frame: the installed unit that must be plumb, level, square, securely fastened, and able to operate correctly.
- Brickmould or exterior casing: trim at the outside edge of the frame.
- Rough-opening framing or suitable masonry substrate: the sound backing that receives required fasteners; brick veneer, mortar, and siding alone are not assumed to be adequate backing.
- Flashing and WRB/drainage plane: components that direct incidental water outward in a shingle-style sequence.
- Cladding: siding, brick veneer, stucco, or another exterior finish that terminates at the opening detail.
- Sill pan and exterior drainage path: a sill pan collects incidental water and must be able to drain to the exterior by the unit- and wall-specific path. Do not seal that path shut.
For example, Andersen’s instructions show side flashing installed over brickmould and overlapping the sill flashing, followed by sealant and a full-width drip cap above the head brickmould. Therma-Tru calls for cap or head flashing beneath the weather-resistant barrier. These are system details, not a universal instruction to caulk every edge.
What are Typical Brick Molding Dimensions?
There is no universal brick-molding size. Face width, thickness, back relief, profile, and projection vary with the manufacturer, material, jamb depth, door or window system, and regional availability. Do not select replacement trim from a presumed standard size.
Measure after removing only enough failed trim to see the actual transition. Record:
- the face width and projection of the existing trim;
- the width of frame edge and frame-to-wall gap that the new piece must cover;
- the visible reveal of the frame that the existing system leaves exposed;
- the distance from the proposed trim edge to siding, masonry, operating hardware, weep holes, and drainage gaps; and
- the actual jamb depth and any manufacturer-required accessory or flashing detail.
Compare those measurements with the exact product profile drawing and unit installation instructions. The replacement must cover the intended transition without burying cladding clearances, flashing, sill-pan outlets, weeps, or operating parts of the door or window.
Different Types of Brick Molding Profiles
Profile names are not standardized. A product called flat, rounded, bullnose, ogee, crown, or channel may be exterior casing, decorative molding, or an accessory profile depending on the manufacturer. Choose from the actual cross-section and installation detail rather than the name alone.
- Flat or simple casing: a straightforward face for a clean appearance and relatively simple replacement work.
- Rounded casing: a softened face that may help match existing traditional trim.
- Decorative casing: a more detailed face, such as an ogee-like shape, used when matching surrounding exterior trim or a historic profile.
- Custom or historic profiles: may be needed to match an existing opening; confirm that the chosen material and finish are suitable for exterior exposure.
- Drip cap: a water-management accessory above head trim when the system calls for it, not merely a decorative brickmould profile.
Brick Molding and Storm Doors
Brick molding may provide a mounting surface for some storm doors, but it is not structural reinforcement. Confirm the storm-door manufacturer’s required mounting width, fastener positions, and solid backing before installation. The fasteners must reach suitable framing or approved backing—not only the trim, siding, mortar, or brick veneer. Stop and obtain professional guidance if the backing cannot be confirmed.
What Are the Best Materials for Brick Molding, and How Do They Compare in Terms of Cost and Durability?
Availability, price, and performance vary by profile and manufacturer, so no universal national cost ranking is reliable. Compare the exact products available for the opening, including finishing, compatible fasteners, sealant, accessories, and future maintenance.
| Material | Useful qualities | Installation and maintenance considerations |
|---|---|---|
| Wood | Familiar, workable, and suitable for painted or stained traditional details. | Prime or seal exposed faces and especially cut end grain. Inspect coating and joints regularly. Repair the moisture source and decay rather than covering deteriorated material with new trim. |
| Cellular PVC | Some products do not require paint for protection. | Movement, fastening, joints, paint compatibility, color limits, and cure time are product-specific. AZEK states that its trim does not require paint for protection, but its installation guide gives specific requirements for movement, fastening, joint treatment, and painting. |
| Composite | Available in some door and trim systems with varying finishes and profiles. | Do not assume it cuts, expands, glues, or paints like cellular PVC. Use its product-specific technical guide. |
| Aluminum | May be supplied as part of a specific door or window system. | Use approved accessories, manufacturer-approved cuts and joints, and corrosion-compatible fasteners. Follow the unit-system detail for coatings and contact with other metals. |
AZEK’s trim and moulding guide is an example of why material-specific instructions matter. Other plastics, composites, fiberglass, polyurethane, and aluminum products may have different rules and should not be treated as interchangeable.
Choosing the Right Brick Molding Profile for Your Project
- Match the unit system first: use the door or window manufacturer’s approved trim detail where one is provided.
- Confirm coverage and reveal: select a profile that covers the intended frame-to-wall transition while retaining the unit’s specified visible frame reveal and clearances.
- Match the exposure: choose material and finish based on sun, rain, and the maintenance the elevation will receive.
- Match nearby trim: select a simple, rounded, or decorative face that fits the architecture, while keeping drainage and flashing details separate from appearance.
- Check the substrate: trim requires solid, reasonably planar backing. Repair rot, failed sheathing, loose masonry, or damaged framing first.
- Check requirements: manufacturer warranties, historic-district rules, and applicable local building requirements may control the profile or detail.
Step-by-Step Guide to Installing Brick Molding
Scope: The replacement procedure below applies only to exterior casing on an existing, sound, correctly installed door or window system. It does not replace the complete installation instructions for a new unit.
New door or window installation: Install the unit according to its complete manufacturer manual before fitting brickmould. The work sequence is generally: repair and prepare the rough opening; establish the sill pan and outward drainage path; install, shim, fasten, and verify the unit; integrate jamb and head flashing with the WRB; install the specified head flashing or drip cap; then install trim and seal only the designated joints. If the required sill pan, WRB integration, head flashing, or cladding transition is missing or cannot be verified, stop and consult a qualified installer. Do not use brick molding and caulk as a substitute for those details.
Work only when the substrate is dry and conditions meet the temperature limits for the sealant, adhesive, paint, and trim material. Wear safety glasses when cutting or prying, gloves when handling flashing or sharp metal, and hearing protection when using power tools.
Installation Steps
- Identify the unit and existing detail. Confirm whether the opening uses brickmould, a nailing fin, an integral flange, separate casing, or an