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 another detail. Obtain the unit and trim manufacturer instructions. Verify that the unit is plumb, level, square, and operating correctly before replacing trim.
- Remove failed trim carefully. Score paint and sealant, then pry off trim without tearing the frame, cladding, WRB, or flashing. Remove loose fasteners and deteriorated sealant. New trim must not conceal rot, loose masonry, failed sheathing, or damaged framing.
- Inspect backing, flashing, and drainage. Check for sound, solid backing along every proposed fastening line. At the sill, identify the pan or drainage detail and confirm that it has an open route to the exterior. At the head, confirm that head flashing or a drip cap sheds water outward over the trim rather than behind it. Where side flashing is accessible, verify that its lower end overlaps the sill flashing/detail in the manufacturer’s specified direction. If these details are hidden, damaged, or unknown, remove enough surrounding material to evaluate them only if you can restore the manufacturer’s system; otherwise stop and hire a qualified installer.
- Correct uneven conditions before fitting trim. The trim face must lie in a supported plane. For masonry irregularities, use a system-appropriate solid, noncompressible build-out or backing that is securely supported; do not bend trim into the irregularity. For siding, account for siding thickness and required clearances at the transition. Do not bridge large unsupported gaps with sealant. Replace loose masonry or deteriorated framing before proceeding.
- Measure the required coverage and dry-fit each piece. Confirm the profile covers the frame-to-wall gap while preserving the intended frame reveal, flashing terminations, and drainage paths. Mark from the visible face, cut one piece at a time, and dry-fit it before fastening.
- Choose and prepare joints by material. A miter may suit a stable decorative corner; a butt joint may be specified for a particular profile; and a scarf joint may be specified on long cellular-PVC runs to manage movement. For wood, prime or seal exposed end grain before installation and use compatible exterior joint treatment where the system calls for it. For cellular PVC, use the manufacturer-approved PVC cement and expansion method where specified. Do not apply PVC gluing or movement methods to composite or aluminum trim unless their instructions require them.
- Fasten into sound backing. Use the trim manufacturer’s specified trim screws or finish nails and specified spacing. Where required, use stainless-steel or hot-dipped-galvanized fasteners. Fasteners must penetrate sound framing or approved backing by the product-specified amount, not merely cladding or veneer. As a product-specific example, AZEK requires corrosion-resistant fasteners with at least 1 1/2 inches of penetration into a substrate and prohibits staples, brads, and wire nails for its trim. That is not a universal rule for every product; follow the exact trim instructions for type, length, location, and spacing. Do not fasten only to siding, mortar, brick veneer, or trim itself.
- Seal only designated joints. Use an exterior-rated sealant compatible with the trim, frame, cladding, and coatings. Seal trim-to-frame or trim-to-cladding joints only where the door, window, or wall system calls for it. Do not seal weep holes, sill-pan outlets, drainage gaps, or a lower edge where sealant would create a water-holding pocket. Follow the manufacturer’s specified bead location, overlap, and termination at head flashing and drip-cap locations.
- Finish and complete the inspection. Remove excess sealant before cure. Finish wood with the specified exterior primer and coating, including cut ends. Paint other materials only when their manufacturer permits it; field-applied paint may not be covered by the product warranty. Observe all adhesive, sealant, and paint cure times before exposing the work to water or operating attached hardware.
Completion Checks and Common Mistakes
- The trim is straight, fully supported, and not forced into a warped or uneven plane.
- Wood joints and cut ends are primed or sealed as required; cellular-PVC joints have the specified cement, scarf, fastening, or expansion treatment; composite and aluminum joints follow their own product instructions.
- Fasteners are seated correctly and reach sound backing, not only siding, mortar, veneer, or trim.
- Head flashing or drip cap sheds outward over the head trim; accessible side flashing overlaps the sill detail as specified; sill drainage, weeps, and pan outlets remain open.
- The door or window operates normally and weatherstripping contacts evenly.
Common mistakes include treating trim as structural support, fastening only into cladding or mortar, using prohibited brads or staples, installing over rot, forcing warped trim flat, caulking all edges, blocking sill drainage, and painting a plastic product with an incompatible coating.
Troubleshooting: If a joint opens, check whether the material needs a movement allowance or approved joint treatment. If trim loosens, inspect backing and fastener reach rather than adding more caulk. If sealant cracks, confirm material compatibility and joint movement. If water appears at the sill, investigate head flashing, side-flashing overlap, the sill pan, and blocked outlets immediately. If a door or window binds after trim work, stop; verify that the unit has not been distorted or fastened through an unintended location.
Professional-stop boundary: Seek qualified help for active water intrusion, unknown or failed flashing, structural or framing damage, extensive masonry repair, displaced cladding, or any storm-door attachment without confirmed solid backing. Follow the unit manufacturer’s instructions, product warranty conditions, and applicable local building requirements.
Essential Tools and Equipment for Brick Molding Installation
Use the following list with the materials and safety equipment specified by the door, window, flashing, and trim manufacturers:
- Tape measure, pencil, level, square, and straightedge
- Miter saw or hand saw appropriate for the trim material
- Drill/driver, hammer or approved nailer, nail set, and manufacturer-specified fasteners
- Pry bar and utility knife for removal work
- Exterior-compatible sealant and caulking gun
- Required flashing materials, primer, adhesive, or approved PVC cement
- Paint supplies for products that are intended to be field-finished
- Safety glasses, gloves, and hearing protection when using power tools
Maintaining and Repairing Brick Molding Profiles
Inspect exterior trim after severe weather and during regular exterior maintenance. Look for failed coating, open joints, cracked sealant, loose fasteners, rot, insect damage, cracks, warping, and staining below the head or around the sill. Clean dirt and mildew with mild detergent and water only as the material manufacturer permits.
For wood, address failed paint and exposed end grain promptly. Repainting frequency depends on exposure, moisture, coating condition, and the coating system—not a fixed calendar interval. Use filler only for small, sound repairs. Replace trim that is soft, extensively split, or decayed after finding and correcting the moisture source.
Cellular PVC and composite trim can still develop movement-related joint problems or loose fasteners. Inspect them even when they need less coating maintenance. Confirm paint compatibility, primer requirements, color restrictions, cure time, and warranty terms before field painting any PVC, composite, aluminum, fiberglass, or polyurethane product.
Conclusion
Choose brick molding by the specific door or window system, the actual profile drawing, the required frame coverage, the condition of the backing, and the wall’s flashing and drainage design—not by a presumed standard dimension. Properly fitted and fastened trim can finish the frame-to-wall transition, but it cannot correct rot, failed flashing, blocked sill drainage, or an unsupported storm-door attachment. Related guidance: What Color Door Goes with Red Brick: A Comprehensive Guide. Related guidance: What Kind of Sand for Brick Walkway: Expert Tips and Solutions.
FAQ
Can I paint or stain brick molding after installation?
Wood can usually be painted or stained with an exterior system suitable for the species and exposure; coat cut ends as well as visible faces. For cellular PVC, composite, aluminum, fiberglass, or polyurethane, verify that field painting is permitted and whether the manufacturer requires a specific primer, paint, color range, or cure period.
How do I maintain brick molding to ensure its longevity?
Inspect for coating failure, open joints, loose trim, cracks, rot, and water staining. Clean it gently, maintain wood finishes as their condition requires, and correct the cause of water entry instead of repeatedly applying more sealant.
What should I do if my brick molding starts to warp or crack?
Check for moisture damage, unsupported backing, unsuitable fasteners, blocked drainage, or material movement. Replace badly damaged sections only after correcting the underlying condition. Do not force warped trim flat or bridge a large unsupported gap with sealant.
Are there design trends for brick molding that I should consider?
Match the profile’s scale and detail to the building and nearby exterior casing. For replacement work, compatibility with the existing unit, correct coverage, and properly detailed flashing matter more than a short-lived trend.