EIFS and Stucco Trim: A Specification Guide for Architects

EIFS trim and stucco trim do the same job on a facade: they frame windows and doors, mark floor lines, cap the roofline and add the shadow lines a flat plaster wall can't give on its own. Specifying them well means choosing profiles that suit the wall system, deciding how each piece is attached, detailing the trim so water sheds away from openings, and calling out the right primer and finish. This guide walks through each of those decisions for cement-coated EPS foam trim on EIFS and traditional stucco, on homes and on commercial buildings alike.

Choosing Stucco Foam Trim Profiles for EIFS and Stucco Facades

Most stucco and EIFS elevations use the same family of elements. Specify them as a set so window heads, sills, bands and the cornice line up and read as one design. Done well, trim is the simplest way to increase curb appeal on a stucco home and gives commercial projects a finished, stone-like facade. For entries and porches, decorative exterior column wraps (non-load-bearing, around a structural post) complete the set. The stucco molding and stucco foam trim hub brings the relevant categories together. If the wall system itself is still being decided, our comparison of EIFS vs. stucco covers the differences.

Scale, thickness and projection

Exterior trim is seen from the street, so it usually needs to be larger than it looks on a drawing. Consider the opening width, the wall height, the projection from the wall face and the thicknesses of the layers it sits over. Hold a sample against the wall, or mock up one opening, before ordering a whole building.

Mouldex trim is sold by the piece and cut and mitered on site, so corners at heads and sills are made in the field. There are no factory corners and no window trim kits; that is what lets the same profiles adapt to every opening size on a project.

Detailing Trim at Windows, Doors and Other Openings

Unlike wood trim, Mouldex trim is moisture-inert and won't rot or warp, but the detail around it decides where water goes, and with it the durability and longevity of the facade. Show these points on the drawings.

Heads

Keep the top of a head trim or crown sloped or protected so water can't sit on it. Show the window head flashing required by the wall system and window manufacturer, and keep it working; the trim goes over the finished wall, not in place of flashing.

Jambs

Leave a consistent sealant joint between the trim and the window or door frame, sized to the sealant manufacturer's recommendation. Don't bury the window's own perimeter seal behind the trim.

Sills

Use a sill profile with a sloped top and seal the joint where the sill meets the window frame and the wall. On drainage EIFS, keep the system's drainage path at the sill clear.

Bands, cornices and other horizontal runs

Any trim that projects from the wall creates a ledge. Specify sloped or protected tops on bands and cornices, and seal the top joint against the wall.

EIFS to brick and stone transitions

Where EIFS meets brick or stone, water and movement concentrate at the joint, so the EIFS to brick transition deserves its own detail on the wall sections. A common approach is to make the material change at a trim line: a band molding or sill-type profile at the change in cladding gives it a clean edge and a shadow line instead of a butt joint between two textures. See exterior band molding.

At the dissimilar-material joint itself, use a sealant joint with backer rod, sized to the sealant manufacturer's recommendation, and keep the trim from bridging it so the joint stays free to move. Provide flashing and a drainage path at the transition so water from the wall above is directed out of the wall, not into the joint. Follow the EIFS manufacturer's published details for the transition. Mouldex trim is adhered over the finished wall, with mechanical fasteners only where the weight of the piece calls for them. The same approach applies to EIFS cornice details at a parapet or roofline: slope and seal the top, and coordinate with the coping and roof flashing.

Joints and transitions

Show where long runs are joined and where trim meets a different material, such as stone at grade or a storefront frame. Joints should be bonded and sealed as shown in the installation guidelines. At expansion or control joints in the wall, carry the joint through the trim rather than bridging it.

Finishing Stucco Foam Trim: Primer, Paint and Texture

Mouldex exterior trim arrives with a uniform cement-gray face. Primer is required on every piece. After priming, the finish is either an exterior latex paint or a textured brush coat.

• Textured brush coat gives the trim a surface close to the stucco or EIFS finish around it, so the trim reads as part of the wall.
• Smooth exterior latex gives crisper edges and works well when the trim is a contrasting color.
• Same color as the wall gives a quiet, monolithic look that suits modern elevations.
• Contrasting color makes surrounds, bands and the cornice stand out, which suits traditional homes, hotels and retail facades.

Both finishes are commonly used, and a wide variety of colors works; it is important to specify the finish in the paint schedule alongside the wall. Like any part of a facade, trim needs periodic care: inspect sealant joints and paint, especially on sills, and touch up as needed.