FAQ

General Questions

What is (I-Block)?

(I-Block) products are lightweight, insulating, stay-in-place concrete forming systems for walls based on technology named (“insulated concrete forms” or “ICFs”).

What can you build with (I-Block)?

Solid, cast-in-place concrete buildings with superior insulation and high durability. Use load-bearing and non-load-bearing (I-Block) walls for basements/foundations, exterior above-grade walls, sound walls, fire walls, and radius walls in residential, commercial, and institutional construction..

How high can I build?

Multi-storey structures can be built with (I-Block), one storey at a time. Each storey is stacked [2.4-3.6m] and poured in [60-120cm] in a continuous pour.

Do the forms stay on after the concrete is poured?

Yes, the EPS stays in place to provide insulation, space to run utilities, and a surface to install finish materials like gypsum board, stucco, stone, brick, and siding.

Does (I-Block) building cost more?

Overall, (I-Block) buildings provide a much better value. Lower recurring costs and higher resale values pay for slightly higher construction costs within a few years.
Construction Costs of (I-Block) buildings are competitive with concrete block and other traditional wall systems. Higher material costs are offset by
– reduced labor costs since (I-Block) combines wall framing, insulation, vapor barrier, studding and sheathing into one step.
– downsizing of heating and cooling equipment
Recurring Costs in (I-Block) buildings are usually a lot lower. Energy savings are documented to range from 40-70% over wood frame, and maintenance costs are lower due to the solid characteristics of (I-Block) walls. ‘Energy-Efficient Mortgages’ can reduce your mortgage payments and insurance premiums may also be lower. In some areas, incredible insurance savings are available.

Is building with (I-Block) considered “sustainable”?

Not just sustainable, but also resilient! You can save up to 41 trees by using concrete products, such as (I-Block) walls, instead of lumber for an average sized home in the US. Concrete is locally produced primarily from abundant natural and recycled materials. An (I-Block) home is super-long lasting (research Pantheon) and offers a significant reduction in energy usage and in insurance premiums in some areas.

How is a (I-Block) wall different from a wood frame wall?

High-mass, reinforced concrete walls built with (I-Block) are usually 8.5 times stronger than wood-framed cavity walls. They also are a better sound barrier (STC Rating of 50+); more resistant to natural disasters, rot, and termites; better insulated (superior R-value) and, therefore, more energy efficient; they reduce air infiltration and the thermal mass of the concrete keeps inside temperatures more even.

How is (I-Block) different from other Insulating Concrete Forms?

(I-Block) is extremely versatile with the highest available true R-value of up to R-59.
(I-Block) offers a complete wall forming solution with track, brackets etc. – not just the foam. (I-Block) provides excellent suppor

Is building with (I-Block) easy to learn for a builder?

Yes. (I-Block) installers find it is easy to transfer basic building skills to (I-Block). Experience in carpentry, masonry, and concrete forming and placement are particularly helpful. (I-Block) offers detailed instructional and technical materials for builders, such as the (I-Block) installation video, product manual, installation guide, and technical bulletins. (I-Block) and our distributors sponsor training seminars and introductory events.

(I-Block) also provides technical assistance via phone, fax, email, and in some cases on-site.

Will it take longer to build with (I-Block)?

Experienced (I-Block) crews can actually build ICF structures in less time compared to wood-frame construction. I-Block wall construction combines numerous lumber-construction steps into one step: structural framing, sheathing, insulating, furring, vapor and air barriers.

System & Wall Characteristics

What are I-Block’s physical dimensions?

Each panel is 48″ long, 12″ high [1218 x 305mm] and 2¼”, 3.25″ or 4¼” thick [58, 79 or 108mm]. The ties are available in six standard sizes creating various concrete thicknesses, and even thicker walls can be built using the Extender Tie.

What is (I-Block) made of?

The panels are made from safe, non-toxic, fire-retardant EPS (expanded polystyrene) and the ties are made from HDPE (high-density polyethylene). (I-Block) panels contain no CFCs, HCFCs, polyisocyanurates, or other toxic chemicals. They do not “off-gas” under normal use nor break down over time.

Is (I-Block) building safer than a wood-framed building?

Yes, reinforced concrete walls are up to 8.5 times stronger than wood-framed buildings. As a result, (I-Block) walls can be far more resistant to earthquakes, tornadoes, and hurricanes when designed appropriately. In addition, I-Block walls have been tested to have 2-4 hour fire resistance ratings. (I-Block) walls, however, are only one component of the building so you should make other building components disaster resistant as well.

What happens to I-Block products in a fire?

Concrete structures are far more likely to remain standing through a fire than structures built with traditional way, (I-Block) products are made from EPS with fire retardant qualities which shrinks away from the heat when exposed to ignition energy. After ignition by a heat source itself extinguishes as soon as the heat source is taken away. If a fire does reach the EPS despite all of the above measures, it will develop dense black smoke within prescribed limits (Smoke Developed < 450, Flame Spread < 25). The smoke from EPS-combustion was found to be considerably less toxic than smoke from natural materials like wood.

Are (I-Block) walls more resistant to rot and mold?

Yes. (I-Block) walls themselves offer no medium for rot or mold to occur because they are solid, high-mass construction, with concrete filling the entire cavity of the forms. Concrete, steel, and EPS are all inert materials that do not rot nor sustain mildew.
However, drywall contains paper which can support mold when combined with excessive moisture. So interior moisture should be controlled using spot removal (e.g. bathroom fans) and properly sized air conditioning units that will cycle long enough to dehumidify the air. In the first few months after construction, additional dehumidification might be necessary in (I-Block) buildings.
Most wood-framed buildings are so susceptible to rot and mold because moisture can get trapped inside the open cavity of the walls despite a patchwork of house wraps, seals, caulk, tapes, and gaskets. The moisture combined with the organic materials allows mold and mildew to develop and rot to occur.

What about termites, ants, and other pests?

EPS provides no food value for termites, ants, or other pests, but they can nest in and channel through the foam. The solid concrete, however, stops them and, unlike wood, the structural integrity of the building won’t be affected. As in other types of construction, local building codes require protecting the foam, especially in high termite infestation areas, which are listed in the International Residential Code. I-Block offers peel & stick termite and waterproofing barriers for below-grade protection. When using I-Block below and above grade, a minimum 6″ bare concrete inspection strip at grade level is highly recommended to force termites to the outside of the foam where they will be visible.

Can I remodel or add to (I-Block) building later?

Yes. Openings can be cut into concrete walls with tools obtainable from most tool rental stores. You can also add more walls by connecting them to existing walls.

Design, Engineering & Building Codes

What wall thicknesses can be built with (I-Block)?

Nominal Concrete Thicknesses of 10 cm, 15 cm, 20 cm, 25 cm, 30 cm can be built using standard (I-Block) components.

How do I determine what size (I-Block) wall to build?

This is a decision to be made by your local building department based on prescriptive designs, or by a licensed engineer. The local building department may allow you to follow pre-approved prescriptive designs, such as the International Residential Code

Do local building departments accept (I-Block)?

While final approval is up to the local building official, (I-Block) has undergone evaluations from the major code agencies in the Egypt, Canada, USA and elsewhere which are often recognized by local officials. I-Block forms solid, flat, monolithic concrete walls, and, therefore, can emulate prescriptive designs that are pre-approved by local building departments.

Does the job need to be engineered?

In today’s regulatory environment, many buildings require some engineering, but check with your local building department. (I-Block) ‘s flat, monolithic concrete walls may conform to pre-approved prescriptive designs available from the local building department.

Do I need a home plan specifically designed for insulating concrete forms?

No. Because of the flexibility of the (I-Block) system, it is not necessary for you to choose a house plan designed just for ICFs. In almost all cases, you have the freedom to choose a house plan from any design company and the (I-Block) materials will adapt to those drawings. The plans, specifications and measurements should be checked by a design professional to ensure that the higher wall thicknesses are properly accounted for.

Doing Business with (I-Block)

How much does I-Block cost?

(I-Block) products vary in price largely depending on chosen configuration and freight. (I-Block) materials are estimated based on the actual components needed for your particular project PLUS a typical waste-factor (important!). Contact your local dealer for a detailed estimate. We’ll need your plans (floors and elevations) or exact wall dimensions – incl. wall lengths, heights, and thicknesses; sizes of all wall openings; numbers of corners/angles/T-walls etc..

Can I see an actual (I-Block) project?

Yes. Contact your local dealer or (I-Block) Representative or look through our photo gallery.

How do I find skilled labor to construct my (I-Block) building?

Contact your local (I-Block) dealer for referrals to contractors experienced with (I-Block). (I-Block) also provides training seminars for contractors.

How do I find an Architect or Engineer familiar with (I-Block)?

Contact your nearest dealer and they can usually recommend an architect or engineer in your area who is familiar with designing with insulating concrete forms. (I-Block)’s Technical Library makes it easy for design professional to incorporate ICFs.

How will my (I-Block) project be supported?

Not only is your local dealer equipped to answer your questions and assist at the jobsite but your local (I-Block) Field Representative is also ready to assist with quantity take-offs, job site training, product seminars and dealer training.

How long does it take to receive (I-Block) materials from my dealer?

Most (I-Block) dealers keep an inventory of common (I-Block) materials. Sometimes their supply might be limited but they can place an order with the (I-Block) factory and usually receive their order within a week or two (in North America, longer elsewhere).

(I-Block) Construction

How much bracing is needed?

Enough to keep the wall aligned during stacking and pouring, generally every 4-6′ [1.2 – 1.8m]. The corner and angle brackets eliminate the need for structural bracing of corners and angles. Refer to the (I-Block) installation videoproduct manual or your local (I-Block) dealer for more details.

Is a special concrete mix used?

With (I-BLOCK) now commonly used in most areas, the local Ready-Mixed Concrete producer will probably have an “ICF Mix” pre-designed and available. The information that the supplier needs is:
1) The specified compressive strength from the building plan;
2) A minimum [150mm] slump (150 – 180 mm preferred);
3) The need for highly “flow able” concrete (e.g. with super plasticizer);
4) Aggregate Size of [10mm] or [20mm] (for walls 20 cm thick or more) and
5) What type of placement equipment is being used (concrete pump, conveyor, etc).
The concrete supplier will determine what mix of locally available materials will give you the best performance.

Do the walls need to be vibrated?

Yes. Use proper placement and consolidation techniques, including using a mechanical vibrator with a small diameter (maximum [32mm]). Do not over-vibrate.

How is electrical and plumbing installed?

Most electrical and plumbing is set into chases cut into the foam after the concrete has set. Electrical boxes, supply lines, and drain lines are affixed directly to the concrete after cutting the foam away. Electrical conduit and some plumbing may also be placed within the wall cavity prior to concrete placement.

How is drywall attached?

Drywall is fastened to the Plastic Ties within the foam with drywall / gypsum screws every 300 mm. An EPS compatible adhesive may be used in addition.

How are exterior finishes attached?

Stucco can be adhered directly to the foam (after rasping it) per the stucco manufacturer’s recommendations, usually requiring a mesh. Wood, plastic or metal cladding is mechanically fastened to plastic ties or, if needed, to “airgap strips” or the continuous fastening strips within the (I-Block) FS panels. Stone and brick are attached according to design specifications (e.g. with brick ledges and brick ties).

Do (I-Block) walls below grade need water-proofing or damp-proofing?

Yes, just like any concrete structure that is exposed to moisture and potentially to hydrostatic pressure. Depending on the site conditions (I-Block) recommends water-proofing or damp-proofing with peel & stick membranes and/or drainage boards. In addition, (I-Block) recommends following all other accepted methods for water management, such as proper drainage, compaction of backfill, and management of run-off for the entire site.

Is a vapor barrier still required for above-grade (I-Block) walls?

No. (I-Block) walls are ‘High Mass’ walls (as opposed to Cavity walls like wood-frame) which don’t need vapor barriers. And the low permeance of the foam and concrete provide a natural barrier against air-borne moisture and air infiltration. This also means that air-borne pollutants, dust, and pollen are kept out of the building by (I-Block) walls.