Floor and Decking Options

With most commercial ICF jobs, wooden floor joists are not the best option. Often the spans, fire codes, and weight loads just won’t allow it. On other projects, sustainability concerns, like energy efficiency and life cycle costs, are driving factors. A number of excellent alternatives exist, all of which work extremely well with ICF construction.

One popular solution is to use prefabricated steel joists. 

FloorSPAN by Metwood and Hambro by CanAm Steel Corporation offer longer clear spans with less joist depth. Openings in the joists make wiring, plumbing and HVAC a cinch, and the joists themselves can be installed by carpenters, saving on labor costs.

“It just makes for a much better building,” says Barry Gow, a Hambro representative based in Ontario, Canada. Gow supplied the joists for a 230,000 sq. ft., 5- story apartment complex in Halifax. (See project profile on p. 18)

Peter Polley, who oversaw the development project explains, “The typical unit involves two bathrooms and a washer/dryer in each of the 64 units. There is such an incredible amount of ducting. If you use regular concrete flooring, you’d have a 7-foot ceiling in half the unit, or have to go to a 9 foot ceiling throughout the building. Hambro gives us the ability to do all the mechanical work within the joist space.” The joists support a concrete slab 3 inches thick.

Polley also used Hambro joists in the Villas at Mont Blanc, which earned Best Residential Development from the ICF Builder Awards in 2005. The Villas feature an in-floor radiant heat system, powered by electric boilers, which allows residents to capitalize on a Nova Scotia program that sells power during off-peak hours at a 30% to 50% discount. 

FloorSPAN by Metwood offers similar advantages. “It’s a structural steel I-beam with the utility holes pre-cut in it,” explains Mike Callahan, owner of Metwood. 

“There are advantages for Metwood beams in just about any application, but especially those that involve concrete floors,” he says.

Coupled with metal pan decking and a concrete floor system, the beams are incredibly strong. “Joists can be placed up to 8 ft apart, and still be strong enough to park cars on,” says Callahan. “When you’re placing the slab, Metwood can span up to 32 feet without any additional shoring required.”

There are other advantages as well. “Any carpenter familiar with light gauge steel studs can install our product. The GC doesn’t need to go to a steel erector because there’s no welding at the jobsite.”

“It installs as fast as anything, and you don’t have to tear anything out,” continues Callahan. “If you do have to use shoring, it’s minimal.” 

Steel decking is another great option for commercial ICF work. Often, all the mechanical and HVAC work will fit into the plenary space created by the joists.

Like Hambro, saving on the depth of the floor joists translates

to savings throughout construction. “
If you save one course of block and three or four courses of brick on every floor of a four story hotel, that adds up,” he says. “It doesn’t take long to realize that this can be a better buy.”

Another effective material for commercial ICF construction is EPS decking. It offers all the advantages of precast, with the additional benefits of being cheaper to ship and easier to finish.

Dave Hall, marketing director at Lite-Form Technologies, which invented Lite-Deck, says, “Transportation costs are a huge thing. With Lite-Deck, you don’t have to haul concrete panels to the jobsite. Foam is not only cheaper to ship, but it’s cheaper to make as well. Plus, you get the quality control of site-cast work.

The product consists of EPS foam planks, which are delivered to the jobsite custom-cut to length. Workers simple lay them out, install shoring and rebar, and then pour. Combined with post-tensioned cables, clear spans of more than 40 feet can be achieved.

Lite-Deck, and similar products such as Insuldeck and AmDeck, are a great option for jobs that require a complete concrete building envelope. A school district in central Oklahoma, for instance, used Lite-Deck to create a tornado-proof roof on two ICF schools in town. (See story on p. 16).

Others use the product with radiant heat flooring. “You’re getting the insulation without any extra work,” explains Hall. Developers of a time-share resort in New England chose Lite-Deck for flooring precisely for that reason. (See story on p. 20).

“We wanted our guests to have the very best,” says Tom Behrens, owner of Mountain Edge Resort. “That meant using ICFs on all exterior and interior demising walls, as well as using foam in the ceiling and floor assemblies.” The result is that each unit is extremely energy efficient and virtually soundproof.

With Lite-Deck, finishwork is simple. Utility chases can easily be cut into the foam using a hot knife or Sawzall. Drywall or other finishes are fastened to the metal furring strips. Hall says Lite-Form can precut the chases for you if desired. 

Mountain Edge Resort used foam decking to provide guests with unmatched quiet, thermal comfort, and luxury. “We wanted our guests to have the very best,” says Tom Behrens, owner of the resort. See story on opposite page for more.

Note that while Lite-Deck can accommodate electrical work, HVAC and other mechanical ducting will not fit in the joist space, as it would with steel joists.

As the commercial ICF market continues to grow, the demand for longer spans, better flooring materials, and more sustainable building practices will increase as well. Steel floor joists and EPS decking are viable solutions to these building challenges. Especially with ICF construction, wood and precast concrete are no longer the only options.