Insulated Concrete Forms Frequently Asked Questions
ThermoForm creates homes and buildings that are more energy efficient, stronger, more sound resistant, and more environmentally sustainable than any other construction method.
Yes. ThermoForm buildings are up to 8.5 times stronger than wood framed buildings. As a result, ThermoForm walls are more able to withstand severe weather.
A wooden or vinyl buck is built and incorporated into the wall as it is being stacked prior to pouring the concrete. Once the concrete is cured, doors and windows are installed as usual.
As with any form of below-grade construction, waterproofing is required. Recommended waterproofing of ThermoForm walls consists of a protective sealant to the EPS and XPS foam, coupled with a drainage mat surrounding the foundation wall. A drain at the footer is recommended and may be required by code. ThermoForm foundation walls should be allowed to cure for a minimum of 7 days and the first floor set in place or the top of wall braced prior to backfilling. The backfill material should be well drained and free of construction debris and large rocks. Once in place, backfill should be properly compacted and graded so that water does not collect around basement walls. Landscaping should be kept clear of the immediate perimeter to prevent accidental water damage from irrigation.
The points at which utilities connect to the building should be identified prior to the pour. This will allow for conduits to be placed through the wall so that the utility can enter. Once the concrete is poured and cured, for ThermoForm channels or grooves are cut directly into the form using and electric hot knife or router. Plumbing and electrical lines are then inserted into the grooves and covered by drywall
No. The combination of concrete and two layers of foam means that the ThermoForm walls acts as a natural barrier against air and moisture.
A ThermoForm wall has a sound transmission classification of approximately STC 50, which is twice as high as a typical wood-framed wall. Loud noises outside a ThermoForm building will be reduced to a whisper inside the building.
Over the last 20 years builders have been asked to build tighter wood homes using house wraps, seals, caulk, tapes and gaskets to reduce the amount of air infiltration/loss in the home. When these products fail, moisture gets trapped inside the open cavity of a wood stud wall, causing mold and mildew problems and rot. ThermoForm is a closed cavity construction, with the concrete filling the entire cavity of the wall. They are resistant to mold and mildew problems because they are composed of three inorganic materials that do not attract water: foam, steel reinforcing bar, and concrete.
Based on research performed by Building Works, Inc, houses built with ICF exterior walls require an estimated 44% less energy to heat and 32% less energy to cool than comparable wood-frame houses. A typical 2000 square foot home in the center of the U.S. will save approximately $200 in heating costs each year and $65 in air conditioning each year. The bigger the house the bigger the savings. In colder areas of the U.S. and Canada, heating savings will be more and cooling savings less. In hotter areas, heating savings will be less and cooling savings more. The energy efficient performance comes in large part from the polystyrene foam on the interior and exterior of ICF walls, which range from R-17 to R-26, compared to wood frame’s R-9 to R-15 walls. Also, ThermoForm walls are tighter, reducing infiltration (air leakage) by 50% over wood-frame homes.
Yes, our certified contractors would be more than willing to assist in the beginning stages of building in order to train individuals.
This will be determined by the design parameters of the building, and in accordance with local building codes.
ICFs have been engineered and built to 48 feet tall (free standing/load bearing).
Standard depth electrical boxes can be cut and fitted directly into the interior foam panel beside a metal or plastic rail by cutting the foam to a 2 ¼” depth (leaving 3/8” foam covering the concrete). Boxes can either be metal or plastic (Nurell® Nylon or other ULC or CUL approved box products). Normally cuts are made using pre-profiled hot knife attachments.
ThermoForm walls have plastic rails that run vertically from the top of the form to the bottom, allowing a fastening strip for mechanical attachments, such as exterior siding, brick ties and drywall. The flange is engineered to withstand high pull out stresses and is designed to keep the materials securely attached for decades. In all cases, most exterior and interior cladding can be installed with common attaching screws.
Most acrylic finishing systems are comprised of a reinforced base coat, optional primer and a 100% acrylic polymer finish. Finishes are available in a limitless color selection and offer performance enhancement options. Exterior acrylic systems are perfectly suited to ThermoForm walls that have exposed exterior foam, as the preparation for applying an acrylic system to the walls requires only rasping the foam before application. Portland cement stucco is also a very durable and can create an endless variety of colors and textures for an exterior of a ThermoForm house or building. When stucco is applied to metal lath, three coats of plaster form a 7/8-inch total thickness. A vapor-permeable, water-resistant building paper separates the plaster and lath from the ThermoForm. It’s a proven system that works in all climates.
Having the right concrete mix design is important to ensure that a project goes smoothly and without incident. In ThermoForm projects, it is recommended that a 3000 psi with a 3/8” smooth aggregate and slump of 5 ½ – 6 be used. However, there have been great advancements in mix design over the past several years that allows one to alter the design mix to provide for better flow and viscosity without increasing hydrostatic (or what is commonly referred to as form) pressure. A common mistake individuals make is adding more water to the concrete on the jobsite to the mix to increase the flow and viscosity. Do not do this. If the slump is above 6, it will cause the form pressure to dramatically increase, causing a tear in the foam form. Instead, consider asking for a percentage of fly ash to be added to the mixture prior to delivery to the mix to increase the flow. Not only is it increasing the flow of the mix, it is also reduces the amount of cement in the system allowing for the increased use of recycled product in the project.
Concrete placement ThermoForm walls is best accomplished with a concrete pump, or alternatively from the truck chute or conveyor belt for below grade applications. Field studies have shown that free fall from great distances doesn’t result in concrete segregation nor in reduction in compression strength. In ThermoForm construction, concrete placement will typically begin by placing concrete through opening in the window sill plate. Subsequent placement will take place from the top of the form, in lifts of approximately 4 ft, for a continuous pour to the final wall height. It is recommended to avoid placing concrete too close to corners, openings or thin columns, in order to not unduly stress the forms. A hose reducer with a flex hose is helpful for more precision placement. During the pour, the ThermoForm walls should be monitored for plumb, and the bracing adjusted accordingly.