What is an ICF Floor?

Although most of us have become somewhat familiar with ICF wall construction, the concept of ICF floors is relatively new to public knowledge. However, as ICF walls are foam pieces assembled together to create a form for concrete that remains in place after the concrete has been poured, the same goes for ICF floors.

A Legalett system consists of a double layer of extruded poly-styrene, reinforcing steel, heating units and embedded ducts (optional), and concrete.

A Legalett ICF floor is an engineered system that involves 2 overlapping layers of foam with pre-cut edge pieces that, once laid together, create a stay-in-place form for a concrete floor, similar to a slab-on-grade. But, there is a difference in technology that makes a Legalett ICF floor more versatile and less costly.

And one major advantage of an ICF floor is the option of having the floor heated or unheated.

Applications of a Legalett GEO ICF Floor

As slab-on-grade
The Legalett system when applied as a slab-on-grade, or floating slab, is a frost-protected shallow foundation that offers several advantages, mainly to cost and time. This slab-on-grade version of the technology is offered both heated and unheated. The heated and unheated version of the floor system can be combined into a single slab to allow for areas such as unheated garages or porches. No digging beyond a few inches is required, and the system is ready to be laid down.
The design of this engineered shallow slab on grade system provides frost protection, while creating a minimal burden on nature at time of installation.
An ICF floor is most often a frost-protected shallow foundation, also referred to as a slab-on-grade. Although unlike some slab-on-grade designs which still require footings and frost walls, a Legalett floor has been engineered to provide the required frost-protection wi thout extra digging.

As a suspended floor
It is possible to incorporate a Legalett system into a suspended floor. We combine the design of Legalett with either the InsulDeck or Hambro floor system products, respective of which application is required. Both systems are up-to-date advanced options and answers to elevated floor construction challenges.

Heated or Unheated?
When considering the Legalett system, one of the questions that needs to be asked is “do I want the most comfortable form of heating available?". If the answer
is no, then focus on the other advantages of this product. If the answer is yes, then let’s talk about the heating.
The concrete slab that becomes the Legalett pad acts like a heat battery. Releasing only one degree Celsius every twelve hours means a very constant but slow
release of heat. This allows for a low-intensity re-charge of heat to maintain the floor temperature. Full dispersion of the heat throughout the concrete ensures
that the floor is not a mix of excessively warm areas with cold spots and ensures even greater savings than radiant heat already provides.
In applications not requiring heat, it is the design benefits that make the Legalett system an advantage. The system design is virtually the same, and is as
versatile as the heated floor.

Point Load Capabilities
Legalett is very adaptable to the underlying soil conditions, and to the bearing requirements of the covering structure. Local soil conditions are analyzed and
incorporated into the engineering for each project, to ensure a solid foundation.
Wall loads & point loads of up to 100,000 lbs can be accommodated within the inherent thickness of the slab, eliminating the need for costly additional work
such as excavation, form work, and extra concrete. This is one of the characteristics of the Legalett system that increases LEED points on projects.

The Technology Behind ICF Floors

Our ICF Floor product line is a very unique and versatile system. The Legalett technology is available for multiple applications, providing options that sometimes are the
only alternative, and other times are simply the better alternative. The Legalett system is engineered specific to each project, to account for the local soil and weather

Benefits of ICF Floors

Environmental – With its high energy efficiency, Legalett systems already make a great choice in consideration of the environment. But Legalett also makes a direct
reduction of environmental impact locally. Because Legalett does not require digging beyond removal of the top organic layer, the ecosystem, including plant and
insect life underneath the build is undisturbed.

Energy Efficiency – A Legalett floor is the most energy efficient form of heating available. The thermal mass of the concrete loses only one degree every 12 hours
and provides a constant temperature. With the low intensity heating of the floor, less heat is required to maintain the programmed ambient temperature, making a
Legalett floor even more efficient than other forms of radiant heating.

Legalett helps meet energy standards such as ENERGY STAR / ENERGUIDE 80, R2000 and contributes to LEEDS points.

Construction Efficiency – A Legalett shallow foundation eliminates several steps normally required to achieve the necessary frost protection. Digging, footing and
frost wall construction, and backfilling is eliminated. Legalett materials come mostly pre-cut ready to install, with each step of assembly detailed on engineered plans.
Legalett installations can be completed smoothly and quickly, helping to advance any project’s progress.

Versatility of Application – there is almost no soil condition that a Legalett floor can’t be built on. During the engineering of the floor pad, Legalett Engineers make
analysis of the given bearing capacity of the area the floor is being built on. This ensures that the Legalett slab will be solid and performs as expected.

Comfort – radiant heated floors is the most comfortable form of providing warmth to a given space. Rather than having a hot surfaces to potentially burn oneself or an
alternation between hot and cold air, the space is a constant temperature as programmed.

The difference with a Legalett floor from other radiant heating is that Legalett takes advantage of the thermal mass of the concrete to use a lower intensity heating to
provide a greater dispersion of the heat and make sure there are no cold spots in the floor.

Health – In the controlled environment created by ICF, unwanted moisture, mould, and mildew are eliminated. Furthermore, with no air being blast through rooms,
dust is also minimized.

The air circulating in the embedded duct work is doing so in a closed loop, as long as the cover remains closed, which means it is kept separate from the air being
circulated through the living space.

Simple Controls – Legalett is not a system that can be changed in temperature in the same way as old-fashioned forced-air heating. Without these radical temperature
variations we achieve maximum efficiency and comfort. Simply set your desired temperature and enjoy living in the most comfortable indoor environment possible.

No Sounds – Unlike many other heating systems which create quite noticeable, even loud, sounds when starting the heating cycle, Legalett is virtually undetectable. The
heating unit sits within the heater box (manifold) that is cast into the floor itself. Once the cover is placed on the heater box, the unit is silent.

Installation Overview

Although installing a Legalett system is not overly complicated, there are certain considerations that need to be taken that can mean the difference between the system
running properly, or not. The below description is of a typical installation on ground, in general terms. For more detailed explanations of each step, please contact us or
join us at one of our training sessions.

Typical installation:

Step 1 – Remove the organic layer from the area where the system will be laid.
Step 2 – Place and level the base layer of crushed stone, as specified by the engineered plans.
Step 3 – Assemble the foam layers and edge elements as per the engineered drawings.
Step 4 – Install the perimeter reinforcement.
Step 5 – (for heated systems) Assemble and put in place the heating system.
Step 6 – Install the main reinforcement.
Step 7 – Pour and finish concrete.
Step 8 – Prime (heat) the floor to raise the internal temperature to drive out unwanted moisture and pre-heat it for the permanent heating unit.
Step 9 – Install the permanent heating unit and seal the access hatch.
Once the system is installed and verified to be running properly, all that remains is to enjoy the comfort and low cost of the Legalett system. The system is virtually
maintenance free.