The DAC-ART Building System is a dry stack concrete block system, but there are others to consider if you are not trying to achieve the look of limestone classic architecture and stand up to hurricanes. Have a look at some of these other concrete building systems. Some are dry stack block systems and further down the page, the ICF systems.
Cresco Concrete Products, LLC - Liteblok - Cresco Concrete Products, LLC produces the Litebuilt® aerated concrete and the innovative Liteblok™ integrated building system. Liteblok™ is an aerated, molded concrete block made in Houston, TX. It is uniquely processed by introducing a non-toxic foaming agent into regular concrete leaving numerous tiny discrete air pockets within the material. The blocks are laid without mortar and are interlocking and lightweight allowing for significant savings in construction time and cost reductions as great as 40% compared to traditional wood frame construction. Liteblok™ built structures are strong and perform well in high winds and during seismic activity. Liteblok™ is a unique product that is patented worldwide. Liteblok™ is very different from all other concrete products on the market and should not be confused with Insulated Concrete Forms (ICF) or Autoclaved Aerated Concrete (AAC). The technology behind the revolutionary Liteblok™ is licensed from Pan Pacific Group of Companies in Australia who developed it more than ten years ago. This technology can be found in over 42 countries worldwide. www.crescoconcrete.com
The Natural Home - A good discussion about using ordinary CMU's in a dry stack block construction project is at The Natural Home. They have some house plan sketches and they offer for sale an instructional DVD about sustainable energy and the HTM passive solar earthhome featured on their website. The discussion on the Dry Stacked Block page includes the following: "Blocks need not be of any special design; they don't interlock, and best of all you don’t have to know how to lay block! You simply stack the concrete blocks in a running bond pattern and then parge coat both sides with a single layer of fiber reinforced, surface bonding cement. Applied 1/8 inch thick (minimum) to both sides, surface bonding cements have strengths that are superior to conventionally mortared block walls and they look a lot better too (no grout lines)! Once your block walls have been surface bonded, hollow vertical cores (minimum every four foot and alongside every opening) are filled with ready-mix concrete and a #5 rebar for an exceptionally strong heat storage mass. Mortared block walls are just as effective, but dry stack is easier for the unskilled homeowner-builder." http://www.thenaturalhome.com/drystackblock.htm
DryStacked.com offers a "How to Drystack a Block Wall" movie available as a download or DVD format. Dry stacked block home construction builds for less by using concrete masonry units (blocks) and a fiber-reinforced Surface Bonding Concrete (SBC) coating. Blocks are simply stacked, and then locked into place by a coating of SBC that is applied to both the inside and outside of the walls. This eliminates grout lines as seen on most block walls and also water proofs the walls. A recent website dedicated to dry stack block techniques and tools... www.drystacked.com
VOBB® Dry Stack Blocks - Verot Oaks Building Blocks Inc. (VOBB®) concrete blocks are dry stacked to create custom homes/buildings which are simple, strong and affordable. You can finish the exterior with brick, stucco, siding, etc. There is no difference in the external appearance of a VOBB® home and that of a conventional home/building. Then you can completely hide VOBB® concrete blocks from the exterior and interior of the home. They have a ton of information on their website and some great photos. I love their motto: "Why cut it with a saw, if you can draw it with a pencil?" Pretty amusing. Besides, I love everything from Lafayette, Louisiana. For a free set of houseplans for custom-designed homes using VOBB® concrete blocks, please e-mail firstname.lastname@example.org or call 866-580-8622 or 337-781-0705. Please type in the word "VOBB®" in the subject line to prevent deletion as a spam email. www.vobb.com
Azar Dry-Stack Block - Azar Dry-Stack Block is a mortarless construction system that is cost effective and efficient. The design of the Azar Dry-Stack Block interlocking system allows for easy and accurate stacking. The blocks interlock both horizontally and vertically, allowing the block to remain level and connected at all times. According to their website, using the Azar block takes general laborers less than a quarter of the time to construct above grade exterior/interior walls and foundations walls. After a wall is constructed, surface bonding or grouting is required. The design of Azar Dry-Stack Block makes this process quite simple. The block aligned cavity is larger than traditional masonry blocks. This makes the grouting process more effective and comprehensive, ensuring each block is properly secured. This is a true dry stacking, mortarless block that requires no special methods or tools for assembly the Azar dry-stack block offers users a host of benefits over stick construction. http://www.taylorconcrete.com/azar.asp
Haener Block - The Mortarless Interlocking System--Stacked without mortar, self-aligning and uniform Haener Block can be laid much faster than conventional block by skilled, semi-skilled or unskilled laborers. A different twist, aesthetically pleasing with its simulated mortar joint. Three years ago, Haener Block LLC, a limited liability company of the State of California was formed to grant patent and technology licenses through the world. Haener Block LLC assists licensees making available mold designs, block computer simulations, house designs and block making and building technical assistance. Check these credentials: The inventor, Dr. Juan A. Haener was born in Romania and educated in Western Europe, received a Master of Science degree from the Technical University of Berlin and a Ph.D degree, summa cum laude, in Theoretical Physics from the University of Vienna. www.haenerblock.com
A construction journal of a dry stack block home--built by Jeanne and her husband Ron who decided to build 'off grid' http://www.offgrid-desert-living.com/dry-stack-concrete-block-interior.html
A Dry Stack Magazine Article from Masonry Journal - Using Imagination to Revolutionize an Industry. They say "Some masonry trades people see these systems as a threat to their livelihood." and "Engineers shy away from specifying dry stacking block systems because they view them as new and untested, although reams of data validating the systems' performance in compressive strength, shear and wind loads, to name a few, prove dry stacking blocks' worthiness in many structural designs." http://www.masonrymagazine.com/3-07/mortarless.html
Besides the DAC-ART Building system that we are using, and which is NOT an ICF system, there are many other concrete building systems that produce a structure that is stronger than the usual stick-built coastal home. Insulated Concrete Form systems, called ICF's are another popular choice. Insulated concrete forms (ICFs) are hollow foam blocks which are stacked into the shape of the exterior walls of a building, reinforced with steel rebar, and then filled with concrete. Insulated concrete forms combine one of the finest insulating materials, Expanded Polystyrene (EPS), with one of the strongest structural building materials, steel reinforced concrete. The result is a wall system of energy efficiency, strength and noise reduction. Here are some of the options in the ICF division of construction?
'Insulating concrete forms' and 'insulated concrete forms' refer to the same thing and you'll see both phrases throughout this web page. However, the term insulating concrete form is more precise because it indicates that the insulating characteristic of the form is continuous and ongoing.
ICF Systems for Commercial Construction and Residential Construction
BuildBlock® insulated concrete forms provide a lightweight, high-strength alternative to using steel or wood frame. Buildblock ICFs are 100% reversible. This can be a time saving feature. This means when you pick up a BuildBlock© ICF, you don't waste your time determining if the ICF needs to be turned up or down or left or right to be installed. BuildBlock 90 degrees and 45 degree ICF corner blocks are 6" longer on each leg than the industry standard. The many advantages this gives to our product include shorter offsets that get you past the crucial short offset. This eliminates many hours of extra corner bracing and extra strapping. BuildBlock© ICFs are industry standard size: 16 high x 48 long but also have a 1-inch repeating cut pattern, feature molded-in horizontal cut lines, have molded-in, numbered vertical cut lines. www.buildblock.com
LOGIX Insulated Concrete Forms wants to make it easy to build green. LOGIX, together with concrete contributes more LEED points than most other building material making it more energy efficient, environmentally friendly, with a 4-Hour fire rating and superior sound resistance. LOGIX products are both cost effective and quick to build and are backed by comprehensive contractor training and installation programs and experienced local Technical Support teams. LOGIX has the power and backing of five ICF manufacturers who operate eight major plants across North America. The commitment to product quality and continual innovation is backed up by over 50 years of ICF manufacturing experience. www.logixicf.com
Fox Blocks offers a high-quality, construction friendly block design at a lower price. It gives you all the benefits of a traditional ICF block – energy efficiency, durability, safety, cost savings and comfort – with special features that make it a better value.
Fox Blocks’ uniquely clever design helps speed construction with easy-to-use reversible, pre-assembled blocks, exceptionally strong ties and special corner brackets for additional strength and easy application of veneer finishes. www.foxblocks.com
Reward's ICF units come fully assembled to save time in the field. The company also promotes a product called the Accelerator, a drop-in piece of galvanized reinforcement for floor or roof ledgers, which can also be used to tie back brick veneers. The units, including corner pieces, are fully reversible, and the ties have a flat surface at each end for fastening drywall, www.rewardwalls.com
Quad-lock units are shipped flat and assembled onsite. They offer three different insulation values: R22, R32, and R40. Plastic furring strips are molded into the EPS foam to make drywall or exterior siding installation easier. The corners (outside and inside) are 90-degree steel angles, which mount on each row. The angle can be changed so that walls can come together at any angle. www.quad-lock.com
Nudura's block system is shipped flat to the jobsite. The plastic ties are permanently mounted to the foam walls, so workers can quickly fold them open. The blocks click and lock together as walls are formed. There are built-in cradles to secure and position horizontal rebar as specified. The forms are also reversible. having no top or bottom, and corner pieces can be flipped to make either left or right corners. Corners of different lengths make it possible to stagger the blocks. There are small indents in the foam to mark the locations for drywall attachment. www.nudura.com
Eco-Block's units are shipped flat and assembled on the jobsite to make blocks of any width, in 2-inch increments. They feature five connector locations that allow for rebar placements wherever specified. This also allows contractors to add more webs within the wall system where concrete pressure is higher and at places where more frequent rebar placement is needed, such as around window and door bucks. It claims to be the environmental leader among manufacturers with 40% recycled materials used in the manufacture of its webs. Eco adds that it has manufacturing sites within 500 miles of any jobsite in the United States and will provide onsite training to help new crews get started. www.eGo-block.com
Integraspec manufactures an "independent panel" system, making it possible to set up inside and outside walls separately. Panels. shipped flat and assembled onsite, can mate with each other in any orientation. It also manufactures 90[degrees] and 45[degrees] corners that can be rotared to fit either left or right corners. Plastic inserts are molded into the foam to make the units stronger and provide an attachment for drywall screws. Cradles in the ties position horizontal rebar, which can be set in 6-inch increments vertically. President Michel Philippe says that with all the support built into the system, you can place as much as 10 vertical feet of concrete in one pass. It's also possible to integrally form columns in the walls, www.integraspec.com
Owner Mike Schwab says that Commercial Block Systems is the only ICF manufacturer focused solely on the commercial market. Its system is designed for speedy installation on the jobsite. No jobsite assembly is required. A steel stud is molded into the blocks to add strength to the unit and serve as the attachment point for interior drywall. Schwab says the strength of the system allows 14-foot vertical concrete placements in one pass. Contractors are encouraged to internally vibrate their concrete to eliminate honeycombing--the units are designed to handle vibration. www.commercialblock.com
Arxx units are pre-assembled and have exposed webs that install flush with the outside of the panel. This makes it easy to locate the fastening points for drywall and exterior cladding. The units interlock when laid up in a wall. www.arxxbuild.com
Amvic has four manufacturing sites in the United States and one in Canada, It manufactures units with a higher than normal foam density (1.5 pounds per cubic inch). In form capacity tests, its units withstood pressures of more than 850 pounds per square foot. The units come pre-assembled--no jobsite assembly of the ICF units is required. Units are reversible, including corners. When in place, the blocks lock together. Amvic reports good concrete flow through the webs. A 1-inch dowel is placed on outside corners for easy attachment of exterior cladding. Insulated concrete form is now available in a 12-inch width for thick-wall applications. Amvic ICFs are manufactured using 2½ inches of 1½-lb/cf expanded polystyrene foam on each side of the form, providing a rigid system that remains straight and plumb and requires less bracing. This system can withstand internal vibration, ensuring proper concrete consolidation. Also available in four-, six-, eight-, and 10-inch widths. www.amvic.com
Offering a full range of products including flat wall and waffle grid designs, PolySteel was the first ICF manufacturer to be recognized by all major code approval agencies. Its use of galvanized steel ties and steel attachment studs, which are recessed 6 inches on center, provides strength, fire resistance and dimensional stability. Its forms can be pre-assembled into panels prior to delivery to the jobsite, resulting in shorter construction times, reduced labor and material requirements, and long-term cost savings. For below-grade installation, Polysteel ICF units are also available in a foam material that eliminates termite infestations. www.polysteel.com
Insulating concrete forms (ICFs) continue to gain popularity for above-grade residential concrete construction. But increasingly, ICFs are also being used for commercial construction. Joe Lyman, director of the Insulating Concrete Forms Association (ICFA), Glenview, Ill., says that over 2005 that 28% of all ICF sales went to commercial projects, a percentage that increases each year. Canada and the Midwestern states lead in this trend. A commercial project is defined by the ICFA as anything larger than a duplex housing project
The leading commercial markets for ICFs are hospitals, retirement homes, churches, hotels, resorts, theaters, multifamily housing, retail stores, agricultural facilities, freezers, and schools. Each of these applications finds different advantages in using ICFs, but the common threads are energy and time savings. Keven Rector, technical services manager for Nudura, Barrie, Ontario, says that owners can expect average savings of 42% for heating and 32% for air conditioning. And in terms of speed, Tom Patton, manager of sales and technical support for Arxx, Cobourg, Ontario, says that one of its contractors recently constructed a building during the winter, finishing three months earlier than an identical building constructed with concrete masonry.
It's not easy to market a new wall system to someone who has a long, successful track record with other systems. Owners, architects, and contractors tend to be faithful to what has worked well for them in the past. So ICF manufacturers trying to nurture the commercial market must be willing to expend marketing resources to convert commercial projects to ICE John Moylan, vice president of sales and training for Reward Wall Systems, Omaha, Neb., says he thinks owners and GCs have the most influence on the choice of a wall system, each for different reasons. When owners retain ownership of their building, energy savings is a big reason why they choose ICFs. GCs, on the other hand, are influenced to try ICFs because of reduced construction time and labor. And designers select ICF systems when they are concerned about building "green"--trying to generate points towards LEED certification for a building.
Here are some reasons it makes sense to build with ICFs:
There are few differences between the products used for residential versus commercial construction. The greater difference is in the sophistication of the construction process. Commercial contractors must be able to develop highly organized jobsite schedules, work in close coordination with other trades, and gain expertise in multistory construction. Commercial work is often unionized so the contractor must be a signatory to trade union agreements and hire workers from the right trade for specific job functions. And because most commercial projects require bonding, contractors must have a good bonding history and be able to bond more than one job at a time.
Moylan says that one marketing challenge is to educate owners to think more about the overall performance of their projects than about initial construction cost. Though most people interviewed for this article said that the productivity of their wall systems has advanced to the point where they are competitive with other wall systems, it's also clear that there are intangible cost savings not always considered on the bid sheet. Chief among these is increased jobsite productivity. Even at current low interest rates, Schwab says, an owner's cost for a construction loan is $8000 per $1 million per month. Finishing early can save a lot of interest expense and get the building in service sooner generating revenue from an earlier move-in.
Owners should also consider savings for HVAC equipment; Schwab says that a downsized system on a recent Oklahoma project saved more than $100,000. HVAC units can be downsized by up to 25% with the help of a knowledgeable mechanical engineer. Monthly savings on energy bills should also be considered part of the real cost. Schwab has testimonial letters showing savings as high as 60% compared with conventional buildings.
What a satisfied owner says Bill Cotton, owner of Cotton's Concrete Construction, Athens, Penn., says they've been doing ICF construction since 1992 and love the work. He's used several manufacturers' products in the past and currently uses Reward. One client is the Towanda Memorial Hospital, Towanda, Penn. Cotton has completed two building expansions for them, the most recent a 21,166-square-foot surgical and outpatient facility with 30-foot-high walls. They were persuaded to use ICFs on the first expansion because of sound attenuation and energy savings. Now it's their building system of choice.