Is a vapor barrier required on the inside face of an ICF wall?
No. The characteristics of an ICF wall with the mass concrete and the EPS insulation provide the required vapor permeance to meet building code requirements as a vapor barrier.
How do you control voids in the wall?
The concrete mix is a high slump 5″- 6.5″ (125 mm – 165 mm) with a smaller aggregate size so the concrete flows easily. The person in charge of placing the concrete should watch the concrete flow throughout the whole wall to ensure there are no void pockets. Internal vibrating provides good consolidation, eliminating voids.
How are Fox Blocks green/environmentally friendly?
Fox Blocks contain a minimum of 40% recycled content by weight.
- Fox Blocks do not off-gas and are not manufactured using any gases that deplete the ozone or are harmful to the environment.
- Fox Blocks require low embodied energy to manufacture.
- Fox Blocks do not contain any materials, that promote mold or mildew growth.
- Fox Blocks are an efficient construction method thereby reducing the amount of construction waste, dust and air pollution in the building process.
- Building with Fox Blocks will save on heating and cooling costs because less air is exchanged between the outside and inside of your home. This also means a smaller more efficient HVAC unit is required for the home.
- Fox Blocks are sustainable. They will not rot or deteriorate for the life of your home.
- Fox Blocks provide a secure, durable, comfortable, long lasting building
Is there a top and bottom on the blocks when installing the Fox Blocks forms?
Fox Blocks forms have a reversible interlock system on all blocks. The robust interlock allows the blocks to fit together very tightly, eliminating any requirement for adhesives. A reversible interlock speeds up the installation.
Is an ICF house faster to build?
The assembly and placement of concrete may take the same time as to build with conventional methods. The advantage with Fox Blocks is that the walls are now insulated, have a vapor and air barrier installed and are ready for finishes once the windows and roof are installed. These benefits will save weeks and/or months depending on the size of the projects.
Can masonry be installed on the exterior walls?
Yes, Fox Blocks has a brick ledge form and the xLerator ledge reinforcement that is designed to support masonry. Fox blocks also has a tieKey accessory which is a specifically made as a masonry tie, to be inserted through the form into the concrete.
Do ICFs promote mold or mildew growth?
EPS is an inert, organic material. It provides no nutritive value to plants, animals or micro-organisms. It will not rot and is highly resistant to mold and mildew.
Can I leave Fox Blocks forms exposed to ultraviolet rays for an extended period (months)?
Yes, but you will notice a light dusting on the surface and a yellowing discoloration of the forms. This does not indicate any detrimental effects to the ICFs. We do suggest, that if the exterior finish is not going to be installed within around a 3 month period or more, the forms be protected from UV rays by installing a temporary building wrap type material. The powdery film must be removed with soap and water before the application of a synthetic stucco finish or waterproofing membrane.
What is the R-Value?
The clear R‑Value of an Fox Blocks is R22, however current Energy codes recognize the lack of thermal bridging in an ICF and the contribution of the mass concrete on the influence of the thermal performance. Whole wall calculations indicate a Fox blocks wall assembly provides an R24 rating.
The continuous double layer (inside and outside) of insulation, the elimination of thermal bridging and minimal air infiltration through the mass concrete wall assembly, allows Fox Blocks walls to performance in the high performance wall assembly category. Completing the envelope with energy efficient windows and doors and roof insulation, Fox Blocks homes can easily meet and exceed energy code requirements and exceed the minimum requirements for Energy Star and EnerGuide. A Fox Blocks structure requires 44% less energy to heat and 32% less energy to cool.
Do I need an engineer to design and stamp Fox Blocks building plans?
Fox Blocks are listed in the building codes (IRC- Sections R404, R611 or NBCC Part 9) with specific applicability limits for residential construction. If the project meets the applicability limits within the building code, a Professional Engineer may not be required (dependent on local building department requirements). A building official has the right to request engineering and in some regions all projects require a professional’s stamp. For any projects that exceed the applicability limits, a Professional Engineer is required for the structural design. Check with your local building department.