ICF FAQ: Insulated Concrete Forms in Middle Tennessee

ICF stands for insulated concrete forms. Hollow foam blocks are stacked into the shape of the wall, steel or fiberglass rebar is set inside, and the hollow core is filled with concrete. The foam stays in place for good, so you end up with a reinforced concrete wall with insulation on both sides.

SuperForm blocks are 4 feet long and 1 foot tall, with plastic ties every 6 inches that hold the two foam panels together and give you screw-in points for finishes.

Source: SuperForm Installation Manual; SuperForm Professional Brochure

SuperForm says its ICF wall completes six major building steps in one process:

• Forming system
• Wall structure (rebar and concrete)
• Continuous insulation
• Air barrier
• Vapor barrier
• Interior and exterior attachment points

Source: SuperForm Residential Brochure

SuperForm Products is a family-owned company started in 1998 by two journeyman carpenters. Its head office is in Pincher Creek, Alberta, and it manufactures in Canada and the USA, including a U.S. facility in West Chester, Ohio.

MID-TN ICF Supply is the authorized SuperForm distributor for Middle Tennessee, based in Murfreesboro. Call or email us for products, pricing, availability, and SuperForm’s technical documents.

Source: SuperForm “Educating Builders” Guide; SuperForm Professional Brochure; superformicf.com FAQ page

SuperForm ICF panels are Type II expanded polystyrene (EPS), 1.5 pcf nominal density and 2½ to 2¾ inches thick. SuperForm’s EPS+ foam insulation is made with a pentane blowing agent, not the HFCs typically used to make XPS foam.

In SuperForm’s 15-year comparison, EPS+ showed 5% water absorption and kept 94% of its R-value, compared with 19% absorption and 52% R-value retention for XPS. SuperForm also states that up to 22 trees are saved by using ICF instead of wood framing on a typical home.

Source: SuperForm USA Structural Guide (BOCA Engineering); SuperForm Insulation Brochure; SuperForm Residential Brochure

SuperForm cites energy savings of up to 60% per year compared with conventional wall systems. It credits three things working together: the thermal mass of the concrete, an airtight wall, and continuous insulation on both sides.

Actual savings depend on your climate and design. SuperForm also notes that an ICF basement alone saves less than a full ICF house, because the savings only apply to the ICF walls.

Source: SuperForm Professional Brochure; superformicf.com FAQ page

SuperForm publishes these figures:

• R-24 stand-alone for its standard block (the product catalogue lists R-23 to R-25 depending on block size)
• R-27 to R-29 for MAX+ graphite blocks
• Over R-40 effective performance, which SuperForm attributes to the thermal mass of the solid concrete core

For comparison, SuperForm puts an average 2×6 wood-frame wall at about R-14.

Source: SuperForm Residential Brochure; SuperForm Product Catalogue (v4, 2024); SuperForm Professional Brochure; superformicf.com FAQ page

Yes. SuperForm states its walls reduce air infiltration by up to 75%. A continuous concrete core with dense foam on both sides eliminates the drafts and cold spots you get with leaky walls.

Source: SuperForm Professional Brochure; SuperForm Hotel Brochure

Thermal bridging is heat escaping through the solid parts of a wall that interrupt the insulation. In an ICF wall, the insulation is continuous on both faces, and SuperForm recesses its plastic ties slightly to prevent thermal bridging. SuperForm describes the result as zero thermal bridging.

Source: SuperForm Installation Manual; SuperForm Residential Brochure

They block a lot of noise. SuperForm’s website gives its walls a Sound Transmission Class (STC) rating of 55, compared with about 38 for a standard wood-framed wall. Higher STC means less sound gets through. (Some SuperForm documents list 54 or 56, depending on the publication.)

Source: superformicf.com FAQ page; SuperForm Residential Brochure; SuperForm Installation Manual; SuperForm Hotel Brochure

SuperForm reports a fire-protection rating of up to 4 hours in ASTM E119 testing, depending on the assembly and finishes, with flame spread under 10 and smoke development under 300. SuperForm puts conventional wood walls at under 20 minutes.

SuperForm notes that drywall is often required over the interior foam to meet fire-rating requirements. Ask us for SuperForm’s fire-rated wall assembly listing.

Source: SuperForm Professional Brochure; SuperForm Residential Brochure; superformicf.com FAQ page; SuperForm Installation Manual

SuperForm states its walls withstand winds up to 250 mph (400 km/h) and have high impact resistance. SuperForm also says concrete cured inside its forms is up to 30% stronger than conventionally formed concrete walls.

Wind performance depends on the whole building design, so have your designer or engineer confirm the details if storm resistance is a priority.

Source: SuperForm Residential Brochure; SuperForm Professional Brochure; SuperForm Hotel Brochure

SuperForm describes its walls as 100% rot and mold/mildew resistant, because the concrete and foam give mold no food source.

Source: SuperForm Professional Brochure; SuperForm Hotel Brochure

SuperForm says the solid concrete core is impermeable to termites, rodents, and insects. SuperForm’s technical manual also includes a termite barrier detail and directs builders to follow local building codes for termite control. Options listed include waterproofing and termite barrier systems, chemical soil treatment, and metal or plastic termite shields.

Source: superformicf.com FAQ page; SuperForm Technical Manual (drawings)

SuperForm says a properly built and maintained ICF home will last for decades. The concrete core does not rot or warp, and SuperForm states its insulation does not break down, off-gas, or lose R-value over time.

Source: superformicf.com FAQ page; SuperForm Professional Brochure

The up-front cost may be slightly higher. SuperForm says energy savings, durability, and lower maintenance often make up the difference within a few years. Because every project is different, call us for a materials quote on your plans.

Source: superformicf.com FAQ page

Possibly. SuperForm notes that incentives depend on your location. Ask us, and we can help with SuperForm’s product documentation for your application.

Source: superformicf.com FAQ page

The ICF block costs more than a concrete block, but a finished block basement needs much more than block. In the example estimate below for a 30′ x 40′ x 9′ foundation, the ICF basement came in about $9,000 lower once labor and the extra layers a block wall needs were added in.

Example only. Prices and labor rates change. Ask us for a current quote on your plans.

Source: Example estimate: CMU block vs. ICF basement

In the example estimate, the block basement needed these extra items: mortar, grout and a grout pump, block-laying labor, 2×4 interior framing and framing labor, R-12 insulation, 6-mil poly, house wrap, and insulation and vapor barrier labor.

With ICF, the foam forms stay in place as the insulation, so those framing and insulation steps are not part of the wall.

Source: Example estimate: CMU block vs. ICF basement; SuperForm Residential Brochure

Yes. SuperForm says waterproofing must be used below grade and must be compatible with EPS foam. Options include peel-and-stick membrane, dimpled drainage membrane, or EPS-compatible spray-on or roll-on products. A perimeter drainage system is always required on below-grade projects.

Source: SuperForm Installation Manual

SuperForm’s installation manual says all walls should be laterally supported at the top with a floor system before backfilling. Backfill should be free of sharp rocks and debris so the waterproofing is not punctured.

Source: SuperForm Installation Manual

SuperForm estimates that an average house basement takes about 160 man-hours to put in footings, stack the SuperForm block, pour, and clean up. Plans with more corners and openings take longer.

Source: SuperForm Installation Manual

SuperForm blocks are 4 feet long and 12 inches tall. Concrete core sizes are 4, 6, 6.5, 8, and 10 inches. Overall block widths range from 9 to 15 inches depending on the core.

The block family includes standard, 90° corner, 45° corner, T-block, top block, brick ledge, one-sided block, 3-inch height adjusters, and end bucks.

Source: SuperForm Product Catalogue (v4, 2024); SuperForm USA Structural Guide (BOCA Engineering)

Very little. SuperForm blocks have 1-inch repeating cut lines to match any plan. Corner, 45°, and T-blocks handle angles and intersections, 3-inch height adjusters fine-tune wall height, and gable walls can be built on slopes up to 12/12. SuperForm lists an 8-foot minimum radius for curved walls.

You can finish an ICF wall with stucco, siding, stone, or brick on the outside, and drywall or virtually any finish inside. The brick ledge block supports brick veneer.

Source: SuperForm Professional Brochure; SuperForm Installation Manual; superformicf.com FAQ page; SuperForm Product Catalogue (v4, 2024)

It depends on the project. SuperForm’s USA Structural Guide gives prescriptive tables for 2024 IRC projects within limits such as:

• Building height up to 35 feet or two stories
• Plan dimensions up to 60 feet
• Floor spans up to 32 feet and roof spans up to 40 feet
• One- and two-family dwellings in Seismic Design Categories A, B, or C

Projects outside those limits need a licensed engineer or engineer-stamped drawings. The guide itself is a reference, not construction documents, so always confirm requirements with your local building department.

Source: SuperForm USA Structural Guide (BOCA Engineering); SuperForm Installation Manual

Openings are framed with window and door bucks before the pour. SuperForm’s structural guide requires reinforced concrete lintels over all openings wider than 2 feet. Its lintel tables cover uniformly loaded spans up to 18 feet. Concentrated loads or longer spans must be engineered.

Source: SuperForm USA Structural Guide (BOCA Engineering); SuperForm Installation Manual

Screw into the plastic ties, which run every 6 inches. SuperForm reports up to 330 lbs of holding strength from a single 2-inch deck screw in its tie. SuperForm’s cabinet detail shows 2-inch coarse-thread screws into the ties at 6 inches on center.

Source: SuperForm Architect/Designer/Engineer Brochure; SuperForm “Educating Builders” Guide; SuperForm Technical Manual (drawings)

SuperForm states its ICF meets ASTM E2634, the U.S. standard for flat-wall ICF systems referenced in the IBC and IRC. SuperForm is third-party listed and audited by QAI Laboratories (listing B1051-1). Ask us for the current listing and code report for your permit file.

Source: SuperForm USA Structural Guide (BOCA Engineering); SuperForm Professional Brochure; QAI listing B1051-1 (qai.org)

Yes. SuperForm’s CAD drawings, BIM files, and 3D models are on its CADdetails microsite. We can also send the installation manual, technical manual, structural guide, and product catalogue. SuperForm’s technical support line is 877-627-3555 or technical@superformicf.com.

Source: SuperForm Architect/Designer/Engineer Brochure

MID-TN ICF Supply in Murfreesboro is the authorized SuperForm distributor for Middle Tennessee. Call 629-543-9843 or email info@middletnicfsupply.com for current products, pricing, and availability.

SuperForm offers a limited warranty on its blocks against material defects. Coverage for installation and finishes may come through your builder. Ask us for the current warranty terms.

Source: superformicf.com FAQ page