by Ian Heisler
Ian Giesler, of ICF Builders, has been involved with ICF's for many years. He has experience with nearly every aspect of the ICF business from manufacturing, design, engineering, sales and marketing to construction.
Doesn't it seem like just when you get a handle on a method or product in the ICF world, a new and better way or product hits the market? When this happens, how do you react? From my experience, there appears to be three types of ICF professionals based on their reaction:
§ Ones that start with a method and product and is reluctant to change for whatever reason.
§ Ones that continue to pioneer new ways of trying to get an old system to work by mixing new methods and accessories with it.
§ Ones that seem to stay on the cutting edge of technology and methodology for attaining the ultimate ICF wall installation.
Having said that, we tried a few new ICF related products earlier this year that figured would enhance our ability to deliver low cost, high quality ICF walls. We know on at least one occasion, we did deliver a high quality installation at an overall lower cost, not only because we have been complimented on the project many times by persons associated with the ICF community, but because we have the numbers to back it up.
The product I'd specifically like to focus on is the VertiForce fibers manufactured by SI Concrete Systems. We've used fibers in the past for ICF walls with results that appeared to be adequate, but there really wasn't an established testing or test protocol for the products we used. Furthermore, when we used fibers in the past, many of the fibers were caught up on the ties of the ICFs, which could lead to the conclusion that the dissemination of the fibers in the solidified concrete wall may have been less than expected or worse yet, less than adequate for the substitution of real reinforcing steel.
On this particular project, we were using an ICF with a 4" concrete cavity, something that we have had trouble with attaining satisfactory consolidation of concrete in the past. We decided to try the new VertiForce technology after spending a great deal of time researching and talking with other ICF installers that used the technology. The results were impressive to say the least.
To begin with, we spent more money on materials and less on labor on this project by switching to fibers. One of the major benefits that fibers offered to us in this particular project is that we eliminated most of the steel reinforcement in the walls. The combination of steel reinforcement and the ties in a narrow ICF wall created a smaller window of acceptable concrete slump variation for placement into the walls. In our case, we placed all 30 yards of concrete in less than 1 ½ hours. This included waiting on ready mix trucks which meant that we weren't affected as great as someone that takes three hours to place 30 yards. Once the desired slump was attained in a ready mix truck, we attempted to discharge and move all of the concrete to its final destination within a maximum 15minute window. By doing this, we weren't hampered by stiffening concrete (although weather typically plays a large part here). For slow moving concrete placing crews, the ability of fiber to use more time to place concrete without adding water for good consolidation within the forms (which in turn aids in avoiding voids) will likely go unrecognized.
On this particular project, we figured we had a material cost increase that resulted in a reduction in labor cost, a reduction of time on the job and a definite curtailment of the problems associated with bent, dirty and awkward rebar. In July of this year, we estimated every project both ways:
§ with fiber and lintel rebar
§ without fibers and our standard grid of #4 horizontally on 16" centers and #5 bars 12" on center vertically
In every case, the substitution of fiber was within 10% of rebar only, that 10% less to 10% more. The key here is that the fiber cost is a set cost whereas labor costs must have some leeway built in.
The big question now is, "Will the ICF installer try to sell the builder and homeowner on the benefits of the fiber vs. plain reinforcing steel or give up without trying?" I believe that the demise of a great product can be hastened forward if the use of it is dependent on the contractor to sell it (which is probably part of the reason that ICF isn't mainstream). Remember, in the past four or five years, the NAHB commissioned studies on what homeowners wanted in new homes. They asked builders the same questions and most builder's answers were opposite that of the homebuyer's. How many carpenters do you know would rather install cement based siding products than wood products even though the cement board products are better than natural wood in terms of value and benefit.
The SI System's VertiForce product is better than regular reinforced concrete. Once this product gets a chance to prove some of the performance, values and benefits, I predict it too will be mainstream. Off the top of my head, the obvious major benefits that we noticed were:
§ The "straightness" of the walls
§ Easy cleaning of the formed wall (we typically use a water hose to flush debris and mud off the footing or slab within the formed wall for a "clean" cold joint)
§ Simple consolidation of concrete without worry of the vibrator head hanging up on horizontal bars,
§ We could conceivably cut the crew sizes from three men to two for stacking or definitely cut the time required to form the walls by a significant amount,
§ It will change the attitude of electricians, plumbers or to anyone who ever had to drill a hole through an ICF wall and realized that 99% of the time, the very location chosen for the hole is right in the path of a piece of rebar (always makes me want to go play the lottery!)
Just like cement board siding products and other products that are now mainstream after having endured much scrutiny, VertiForce has qualities that improve upon existing products and methods without premium prices. On most ICF projects, the material prices are a given while the cost of time and labor is the unknown. The introduction of the fibers reduces the uncertainty enough to make a wise contractor take a hard look at using fibers and take on the responsibility of explaining the value to the builder or homeowner.
Like all new products that bring change along with it (including ICFs), a certain percentage of people will embrace it and a certain percentage (typically equal) will scoff at it. Over time, the majority will move from the extremes to a central level of acceptance, a phenomenon with nearly every new product or idea.
One of the ways to fast track further acceptance of ICFs is by gaining credibility of outside interests. In this case, we should do our part to help the very people that are trying to help us by at least trying the product and offering feedback. "Fibered" concrete will become a norm, just like ICFs.However, fibers will be a tough sell unless the ICF installer says, "We are going to use fibers", because we all know that once the concrete is placed and the walls are finished, the only people that really know that the house is an ICF house is the homeowner. And they get a reminder each month when they open their utility bill.
I realize this editorial appears to be an endorsement of a particular brand name product. Since it is the only recognized product of its type and it is a good product, then a positive commentary would only appear to be an endorsement. After all, good products and services get good reviews! If you don't have basic knowledge of fiber products, perhaps the time it takes to request information is time well spent. The alternative is to let the client (be it the builder or homeowner) either educate you or appear to know more than you about the changes on the way in our own industry. Synthetic Industries' concrete fiber web site is www.fibermesh.com