FAQ.

The FOX BLOCK form unit has a fastening strip located every 8” (200mm) on center. These fastening strips are continuous up the full height of the form unit and have a patented mechanism that interlocks one fastening strip to the one below or above it. The fastening strips are indicated on the surface of the form by a diamond pattern. They are 1½” wide and have a higher pull-out strength than a dimensional stud. Different types of cladding will have different installation procedures.

In our FOX BLOCK Insulated Concrete Forms, the insulation is made of EPS, and the webs are composed of high-density polypropylene made from 100% post-consumer recycled plastic. The EPS and the plastic are totally inert and emit no gases or hydro-soluble substances.

When using the FOX BLOCK ICF for a foundation wall with stepped footings, the best increment to use is 18” (450mm). Since the height of the form unit is 18”, you can cut a standard form unit in half for a 9” (225mm) increment. This is also a favorable increment for stepping footings.

EPS foam is an inert material, meaning it is very slow to react and has no active properties. However, this does not mean that mold will never develop on an ICF wall simply because it uses EPS insulation. If there is insufficient airflow, excess moisture can accumulate through condensation near openings. This buildup of water, if not evaporated, can cause mold to grow on the paper surface of drywall. That’s why, when designing your HVAC system, it’s important to adjust it appropriately for a tighter building envelope.

There is no height limit for FOX BLOCK ICF buildings. FOX BLOCK has been used in many commercial projects that have risen multiple stories using the system to form structural walls.

FOX BLOCK is Green in several ways. The material of the webs is 100% recycled. The material for the foam is 100% recyclable. Using FOX BLOCK as opposed to traditional building methods cuts down the amount of wood used, which has become a precious commodity. By reducing waste and shipping space required, FOX BLOCK also impacts the environment in a very positive manner.

FOX BLOCK Insulated Concrete Forms come in 5 different core sizes. Standard thicknesses are 4” (100mm), 6” (150mm), 8” (200mm), 10” (250mm) and 12” (300mm). FOX BLOCK also sells the form units in unassembled forms as well for flexibility. With the 4-Way Web Connector, you can now take any of the thicknesses mentioned above and combine them for different combinations of larger sizes. Ask your local distributor about the 4-Way Web Connector and what you can do with it.

Your plans do not HAVE to be designed for FOX BLOCK Forms. It helps the construction process go faster if the modular dimensions of the form unit are considered; however, FOX BLOCK’s forms are flexible in that you can adapt them to an existing design. Should you want to design using FOX BLOCK’s most optimal dimensions, ask your local distributor for the Dimension Layout Guidelines.

Although the joints between the FOX BLOCK form units are tight, below grade a waterproofing is still necessary. FOX BLOCK sells a peel-and-stick waterproofing that is easy to apply and carries a warranty of two years. This membrane must cover the foundation walls. In situations where you have an attached garage, the below-grade wall shared with the basement must be covered, and a 4’ (1200mm) overlap to the adjacent walls.

According to the standard ASTM E 96, to qualify as a vapour barrier, a material must not exceed 45 ng/Pasm². This unit denotes the ‘permeance’ of the material—how much moisture per force applied (air pressure), in a second over a square area. Our EPS foam has a permeance value of 36 ng/Pasm²; therefore, the FOX BLOCK Type II EPS qualifies as a vapour barrier.

The best method is to rip a plywood strip 2 to 2½″ wide and screw it into the webs along all the walls. Fasten these strips at every fourth web. The drywall contractors can then set their drywall on top of the strip and cut their top sheets accordingly to suit this height. The result is a continuous wood fastening surface for nails along the wall, and the plywood will be fully covered by the baseboard.

The FOX BLOCK form panel thickness is 2⅝”, which is deep enough to accommodate almost every standard-depth electrical box. Deeper boxes can easily be installed by gluing a square of foam on the inside of the form at the planned box location during the pre-pour phase of installation.

The FOX BLOCK form unit has a fastening strip located every 8” (200mm) on center. These fastening strips are continuous up the full height of the form unit and feature a patented mechanism that interlocks each strip to the one above or below. The fastening strips are indicated on the surface of the form by a diamond pattern. They are 1½” wide and have a higher pull-out strength than a dimensional stud. Different types of cladding will have different installation procedures.

A standard #6 x 1½” to 1¾” coarse-thread “bugle” or “flute” head (¼” dia.) zinc-coated or otherwise non-corrosive screw works well. Avoid drywall screws with black sulfur coating—they will eventually corrode. Also suitable are bright-finish (chrome-like) #6 x 1½” pan-head coarse-thread self-tapping screws, which are corrosion-resistant and versatile for many anchoring applications beyond siding.

To reach your desired wall length, use a combination of standard and corner form units, trimming lengths as needed. The FOX BLOCK form is designed for easy measurement. Each interlock along the top and bottom equals 1”, and the score lines on the outside of the form panel denote 2”. Since the webs are spaced 8” apart, these three reference points make it simple to identify where to make precise cuts.

In our FOX BLOCK Insulated Concrete Forms, the insulation is made of EPS, and the webs are composed of high-density polypropylene made from 100% post-consumer recycled plastic. Both materials are completely inert and emit no gases or hydro-soluble substances.

If the average temperature over a three-day period is below 40°F (4.5°C), this is considered a cold-weather pour. Concrete can be heated, and the mix adjusted for these conditions. With proper provisions, the full compressive strength of the concrete can still be achieved. For more information, contact your local FOX BLOCK distributor.

Cut a hole in the bottom of the wall matching the diameter of your forced-air tube. By connecting a piece of duct to this hole, you can blow warm air through the cavity to melt the ice. To accelerate the process, cover the top of the wall with an air barrier to retain heat.

When using the FOX BLOCK ICF for a foundation wall with stepped footings, the best increment to use is 18” (450mm). Since the form height is 18”, you can cut a standard form unit in half for a 9” (225mm) increment. This is an ideal measurement for stepped footings.

A lift height refers to how high you pour concrete in one pass around the wall perimeter. According to ACI 318 standard practice, lift heights should be 4’ (1200mm) per hour.

Concrete is typically poured in 10–12’ (3050–3658mm) levels. Therefore, according to the previous question and answer, a typical pour consists of 2–3 lifts.

The concrete must be vibrated to properly consolidate. When consolidating concrete after pouring, it should be done in a consistent manner—dipping the “stinger” the total height of the lift. The vibrator should be inserted into the concrete at every second web to ensure full consolidation.

EPS foam is an inert material, meaning it is very slow to react and has no active properties. However, this does not mean that mold will never develop on an ICF wall simply because it uses EPS insulation. If there is insufficient airflow, excess moisture can accumulate through condensation near openings. This buildup of water, if not evaporated, can cause mold to grow on the paper surface of drywall. That’s why, when designing your HVAC system, it’s important to adjust it appropriately for a tighter building envelope.

There is no height limit for FOX BLOCK ICF buildings. FOX BLOCK has been used in many commercial projects that have risen multiple stories using the system to form structural walls.

FOX BLOCK is Green in several ways. The material used for the webs is 100% recycled, and the foam material is 100% recyclable. Using FOX BLOCK instead of traditional building methods significantly reduces the amount of wood required—an increasingly valuable resource. By minimizing waste and reducing shipping volume, FOX BLOCK positively impacts the environment in multiple ways.

FOX BLOCK Insulated Concrete Forms come in five different core sizes. Standard thicknesses are 4” (100mm), 6” (150mm), 8” (200mm), 10” (250mm), and 12” (300mm). FOX BLOCK also offers unassembled forms for added flexibility. With the 4-Way Web Connector, you can combine any of these thicknesses for larger wall configurations. Ask your local distributor about the 4-Way Web Connector and available options.

Your plans do not have to be designed exclusively for FOX BLOCK forms. However, considering the modular dimensions of the form unit can speed up the construction process. FOX BLOCK forms are flexible and can easily adapt to existing designs. To design using FOX BLOCK’s optimal dimensions, contact your local distributor for the Dimension Layout Guidelines.

Although the joints between FOX BLOCK form units are tight, below-grade waterproofing is still necessary. FOX BLOCK offers a peel-and-stick waterproofing membrane that is easy to apply and carries a two-year warranty. This membrane must cover the foundation walls. In cases where there is an attached garage, the below-grade wall shared with the basement must also be covered, with at least a 4’ (1200mm) overlap to adjacent walls.

According to the ASTM E 96 standard, to qualify as a vapor barrier, a material must not exceed 45 ng/Pasm² in permeance. This unit measures how much moisture can pass through under pressure per second over a square area. The EPS foam used in FOX BLOCK has a permeance value of 36 ng/Pasm², meaning the FOX BLOCK Type II EPS qualifies as a true vapor barrier.

Absolutely. FOX BLOCK walls can support heavy loads such as cabinets and televisions. For installation details and best practices, please refer to the resources section for examples and guidelines.

EPS foam is an inert material, meaning it is very slow to react and has no active properties. However, this does not mean that mold will never develop on an ICF wall simply because it uses EPS insulation. If there is insufficient airflow, excess moisture can accumulate through condensation near openings. This buildup of water, if not evaporated, can cause mold to grow on the paper surface of drywall. That’s why, when designing your HVAC system, it’s important to adjust it appropriately for a tighter building envelope.

There is no height limit for FOX BLOCK ICF buildings. FOX BLOCK has been used in numerous commercial projects that have risen multiple stories using the system to form structural walls. 

FOX BLOCK is environmentally friendly in several ways. The material used for the webs is made from 100% recycled content, and the EPS foam is 100% recyclable. By using FOX BLOCK instead of traditional building methods, the amount of wood required is significantly reduced—helping preserve a valuable natural resource. Additionally, by minimizing construction waste and reducing shipping volume, FOX BLOCK contributes to a smaller environmental footprint and promotes sustainable building practices.

Absolutely. FOX BLOCK ICF walls are engineered to handle substantial loads such as cabinetry, shelving, and wall-mounted televisions. For the best results and recommended fastening methods, refer to the resources section for detailed installation techniques and examples of best practices.