Building an insulated concrete form (ICF) building or house allows for the application of many types of exterior finishes: masonry veneers, stucco, panel siding, vinyl or wood siding, and fiber cement boards. If you can install the finish on a traditional wood-frame structure, you can install it on an ICF wall. However, the application of exterior finishes to the solid substrate of an ICF wall provides more strength and durability than when applied to a wooden skeleton. ICFs typically provide fastening points for exterior finishes at 8" on center, plus addition fastener points at corners. The versatility of sidings for ICF allows you to achieve all your design and aesthetic goals for the structure. The choice of exterior finish comes down to your personal decision, cost, and local styles.

How to Pick the Best Exterior Finish for Your ICF Project

While ICFs do not limit the application of any sidings, several factors play into selecting the right one for your project: cost, aesthetics, ease of installation, and location. Some sidings offer more durability; others reduced costs, and some provide moisture-resistance. The success of all the cladding, whether masonry veneers, stucco, or panel, fiber cement, and vinyl sidings, depends on proper and professional installation.

1. The Ease of Applying Masonry Veneers to an ICF Wall

Masonry veneers (brick and natural stone) easily installs over the ICF surface with ICF masonry anchors set into the concrete. Builders must consult with the ICF manufacturer on the proper anchors for their wall system. Also, before installing the anchors, contractors should review the construction documents for anchor spacing specifications.

The characteristics of an ICF eliminate the requirements for a weather resistant barrier or building paper in the air cavity of a masonry veneer.

Masonry veneers provide several advantages as an exterior finish. Masonry veneers come in a large range of sizes and colors, which allow for many aesthetic options for building and home owners. Furthermore, masonry veneer’s durability stands up to severe weather, which ensures the exterior finish integrity for years to come.

Simulated stone veneer siding is directly applied to the ICF substrate with product specific adhesives.

2. Stucco Cladding Over ICF Provides Many Benefits

Stucco provides a beautiful exterior finish for ICF. Stucco provides a weather resistant finish to the ICF. Other advantages of stucco include rot-, rust-, and fire-resistance. Stucco cladding comes in three types: traditional stucco, exterior insulation and finish systems (EIFS), and thin-coat acrylic stucco. ICF typically utilizes the thin-coat stucco method because it allows for quicker and less expensive installation than traditional stucco and EIFS.

An ICF substrate is EPS which allows for the direct application of thin-coat acrylic stucco. This eliminates the need to install an additional EPS layer over the wall assembly.

Traditional stucco, using a metal lath is directly applied to the ICF with the lath secured into the ICF fastening strips.

The success of the stucco application depends on proper installation, including details at openings, transitions, and the edges of the wall cladding. Architectural detailing of the exterior may be enhanced with additional EPS molding, trim, window trim, etc. easily adhered to the EPS of the ICF for stucco applications.

3. Panel Siding Offers a Cost-Effective Exterior Finish for an ICF wall

Sheet panel siding provides one of the quickest and most affordable options for an exterior finish for ICF. Panel siding contains shiplap edges so that one sheet laps onto its neighbor. Panels come in 4 by 8, 10, and 12 feet long sizes. Common panel sidings include smooth-sawn, rough-sawn, cement-fiber, and pressed hardboard.

Wood siding or wood panels must be installed on furring strips that are attached directly to the ICF. This provides an air gap behind the wood to prevent moisture build-up and future rot.

Vertical siding options may also require horizontal furring strips installed to meet siding fastener spacing.

All sidings must be installed per the manufacturer's instructions.

4. Fiber Cement Siding Provides a Durable and Strong Cladding

Prefabricated fiber cement siding provides several pros and cons when applied as an exterior finish to ICF. Fiber cement siding stands up to wind, rain, hail, fire, insects, and even hurricane-level storms. Fiber cement siding comes in many colors and textures, including some that mimic wood shingles. Any vertical style siding requires horizontal furring installed over the ICF to provide proper siding fastening spacing.

Installing cement board can cost two to three times more than vinyl siding - mainly due to fiber cement requiring more manpower to deliver and install than other methods. Also, fiber cement needs repainting, unlike vinyl siding.

5. Vinyl Siding - a Quick and Affordable Exterior Finish for ICF

Durable and tough vinyl siding, made from PVC plastic resin, comes in many styles and colors. Vinyl siding installs quickly and provides an affordable siding for ICF. Unlike metal and aluminum, vinyl does not rust, conduct electricity, or dent. And, unlike wood, it won’t warp, rot, or chip. It also holds up against outside elements like the sun, rain, and wind. Vinyl siding pairs well with a variety of exterior window trim ideas as well. Overall, vinyl siding provides a long-lasting, reasonably priced product for the exterior finish.

Vinyl siding can crack or break upon impact. Also, if not installed properly, it can leak and detach.

Is There a Right Exterior Finish for Your Project?

While ICF construction allows all types of exterior finishes; essentially, the choice of exterior finish often comes down to your personal decision, cost, ease of installation, and climate. Of importance, however, the effectiveness of the exterior finishes depends entirely on the correct and professional installation.

ICFs provide an excellent solid substrate for the application of any and all exterior finishes.

Please contact Fox Blocks professionals for more tips on the best exterior finishes for your ICF project.