FAQ

WHAT IS ICF?

ICF stands for…. “Insulated Concrete Form.” An ICF block is an expanded polystyrene modular building form made for erecting concrete walls cost effectively. They are designed to be put in place quickly and are structurally strong enough to withstand the fluid pressure of the concrete that is poured inside to fill the wall up.

WHAT DOES AN ICF HOME LOOK LIKE WHEN IT IS FINISHED?

An ICF Home looks like any conventional new home on the inside and on the outside. The window sills are deeper since the walls are thicker. Very few people can tell the difference between ICF construction and other types of construction.

 

WHAT KIND OF SIDING CAN BE USED ON ICF SYSTEMS?

Virtually any exterior finish can be used with an ICF System. In fact, stucco is much more cost effective to apply over an ICF wall because the foam is already in place.

It is important to note that stucco when applied over wood in a conventional wood framed home can lead to wood rot and mold. In an ICF wall there is no wood to rot or warm dark wall cavity to grow mold!

WHAT IS THE R-VALUE OF AN ICF WALL?

A typical ICF wall with a 6” concrete core will have an equivalent R-value of 50. Both the inside and outside panels of 2 5/8” EPS foam have a R-value of 22. When combined with the thermal mass of the concrete, the actual performance is much higher.

WHAT KIND OF FOUNDATIONS CAN BE USED WITH ICF?

Any type of foundation (Stem-wall, monolithic, off-grade, piling, hollow core, etc.) can be used with ICF walls. The only requirement is that rebar must extend out of the slab or footer to connect the ICF wall to the foundation.

CAN AN ICF HOME BE BUILT ON PILINGS?

Yes. We form and pour an elevated beam that connects the pilings, and supports the ICF wall. The other method is to form and pour an entire elevated slab before we go up with the ICF walls. The floor can be formed conventionally, with “Lite-deck”, or with hollow core panels.

DO ICF WALLS SWEAT?

No they do not. EPS (expanded polystyrene) is a poor conductor of heat and cold. Therefore, water vapor that may be present in the structure will not condense on the walls. The EPS is open cell and repels liquid water but allows water vapor to pass through which allows the building to breath. It works very similar to GORTEX.

WILL MOLD GROW ON ICF WALLS?

No. ICF forms are made of expanded polystyrene, which is inorganic. It is not a food source and therefore will not support the growth of mold.

CAN TERMITES EAT ICF?

No. Termites do not eat the foam in ICF because it is inorganic. Termites can, however, burrow through the foam to get their favorite food……wood. This is a problem in traditional wood frame structures when foam is added as a base to apply stucco, but is not a problem with ICF homes as the structure is made of concrete. As far as we know, termites don’t eat concrete!

SHOULD THE CONCRETE BEING PLACED IN ICF FORMS BE MECHANICALLY VIBRATED?

Yes, All concrete placed in ICF forms should be consolidated using a vibrator. Most ICF Forms are engineered to withstand the rigors of internal vibration. "Patting" or "tapping" the exterior of the forms is not an effective method of concrete consolidation.

IS ICF MORE EXPENSIVE TO BUILD WITH THAN TRADITIONAL STICK FRAMING?

Yes. Costs vary depending on the specifics of each project, but usually the project total will be 7%-10% higher overall than with a similar traditionally framed wood house. ICF homes are so energy efficient that the cost difference is typically recouped in energy savings and may even amount to a lower monthly out of pocket expense. Also, most insurance companies offer substantial discounts for using ICF since the walls are 4 times more fire resistant than wood walls and the physical structure is also stronger.

ARE ICF'S FLORIDA PRODUCT CODES APPROVED?

Good question! There are many different brands of ICF on the market. Coastal ICF uses Florida product approved products. It is always a good idea to verify that the products you use have been approved by the state. VISIT FLORIDA BUILDING >>

WHAT ARE THE MAIN BENEFITS OF BUILDING AN ICF HOME?

ICF homes are stronger, safer, quieter, and more energy efficient than wood frame or concrete block houses.

ICF walls are built with steel reinforced concrete and fire retardant expanded polystyrene foam. When compared to wood-framed walls, ICF walls are far more resistant to the spread of fire and are far more likely to remain standing after.

WHY DON'T I SEE MORE HOMES BUILT OUT OF ICF?

ICF built homes are expanding rapidly. In some areas of the country, energy codes and other local conditions contribute to widespread use of ICF’s. Many cities are beginning to use ICF’s for their low-income housing; realizing that while the home may cost slightly more to build, it is much less expensive to live in and maintain. More and more developers across the nation are constructing communities entirely of ICF’s.

HOW LONG DOES IT TAKE TO BUILD?

An ICF home can usually be built in the same amount of time as any other type of home. Commercial structures can often be built quicker, due to the combined steps of framing and insulating. Large sections of wall with few offsets and openings also contribute to the speed of building with ICF’s.

ARE THERE ANY CHANGES TO THE HVAC SYSTEM IN ICF HOMES?

Yes. The most common difference is to use a variable speed air handler. The A/C system not only cools but de-humidifies the air in your home. ICF homes are so energy efficient that the air conditioning may remain off for long periods of time. To avoid “short cycling” the variable speed air handler runs in a slower, more continuous, and energy efficient mode. This slower cycle not only provides cooling but continuous de-humidification as well.

WHAT SERVICES DOES COASTAL ICF PROVIDE?

We provide several levels of involvement. We will work as a subcontractor with you or your builder to build the ICF walls. We can construct the entire building envelope to include the foundation, ICF walls, and wood or metal framing. We also occasionally provide scaffold rental and technical support for do-it-yourselfers.

CAN I BUILD AN ICF ADDITION?

Yes, as long as the area is accessible. An ICF addition can be used as a safe room in the event of a storm.

HOW DO YOU PROTECT THE EXPOSED FOAM BETWEEN THE GRADE AND THE SIDING?

A cement-based product is applied with a trowel over fiberglass mesh which is attached to the ICF wall. This gives it protection from stones, water, and other hazards.

WHICH ICF BLOCK DO YOU USE?

There are many different brands of ICF forms available, but not all blocks are created equal..…or approved for use in the State of Florida. We have installed many other brands of block, but have found that the end results with NUDURA are the best. It is a fifth generation block which means that it has been around for awhile and there are no hidden problems with the block that are common with other brands. NUDURA is user friendly to transport, store, and install. We guarantee our walls with NUDURA. The technical and logistical support is outstanding. VISIT THERE SITE >>

WHAT IS THE ICF BUILDING PROCESS?

Building an ICF home isn’t that different than any other type of construction. You will need to have a few slightly different details in your building plans so it advisable to find an architect or home designer who is already familiar with ICF. Once you have the blueprints, and a builder, we will estimate the cost of the ICF walls.

To get a building permit, you will also need a load calculation from Gulf Power. This is a heat loss/gain analysis on the structure which takes into account the high thermal mass and high energy efficiency of the ICF wall. The results of this analysis are used by the HVAC contractor to design the A/C system.

The sequence of construction is almost the same as any other type of construction. Once the foundation is completed, the ICF walls are built.

After the exterior walls are poured, the interior walls are framed and then the roof put in place. If it is a two story, a floor system is installed and then the next level of ICF is built. After the building is “dried-in” the utility subcontractors install the HVAC, plumbing, mechanical, and electrical systems. Any utility penetrations through the walls are sleeved in prior to the wall pour.

The wall pour usually takes just a few hours. We use a concrete boom pump to place the concrete. Once the wall is filled up, anchor bolts and/or hurricane straps are set in place and the walls are straightened using our bracing and alignment system. The next day the bracing is removed and project is ready for the framer to build the interior walls. Trusses are attached to the top of the wall using individual hurricane straps for each truss. A truss strapped to a concrete wall will resist hurricane-force winds much better than those attached to a wood framed wall.

There are a few nuances that make building with ICF slightly different, but all in all the process is basically the same.

 

          FAQ

Coastal ICF | tel: (850) 477-7486 | fax: (850) 477-5008 | email: doug@coastalicf.com | Copyright © 2007 Coastal ICF