Light-wood-frame construction* was first utilized by carpenters nearly 100 years ago, replacing the heavy-timber construction typical at the time. Light-wood-framing became more widespread as the availability of cheap machine-made nails and properly cut and planed pieces of wood increased. Today, light-wood-platform-frame construction** is popular in the United States because it is light, quick, renewable, and does not require heavy tools or equipment. Wood-frame components are also easily customizable. However, architects, contractors, and building owners have several significant challenges associated with wood-frame construction: water intrusion, fire, insects, and durability. There are also several smaller problems like excessive waste, poor acoustics, and limitations on architectural styles. Nevertheless, even with these challenges, wood- frame construction continues to be common in the United States.
Challenges and Problems with Wood-Frame Construction
Moisture Accumulation within the Wall Assembly of Wood-Frame Construction
Energy-efficient wood-frame buildings can be vulnerable to moisture accumulation in the wall cavities. High moisture within a building's cavities is serious because moisture can lead to wood rot and costly repairs. High moisture can also cause the growth of mold, which is unhealthy to the occupants of the building. A wood-frame building envelope must control moisture entry, accumulation, and removal. Controlling moisture within a wall cavity is challenging to builders and designers because effective methods that prevent moisture from entering a wall cavity may also prevent the moisture from leaving the wall cavity. Managing moisture in wood-framed buildings requires proper selection of materials for the particular climate zone, proper management of the heat, air and vapor flow throughout the building’s envelope, and management of rain and other precipitations. To prevent decay and the growth of mold, the design of a high-performing wood-framed building must prevent accumulation of moisture within the wall assembly.
Fire Protection in Wood-Framed Construction
Wood is combustible*** and vulnerable to fire damage. Wood-frame buildings are especially susceptible to fire damage during construction before builders have placed fire protection over the frame****. The challenge to contractors of wood-framed buildings is to prevent potential fires and, in the event of a fire, to limit the spread of flames. Restricting the spread of fire is accomplished by cladding the wood-frame in materials that resist heat and flames and treating the wood with fire retardants. Fire prevention and resistance are essential and challenging issues to builders of wood-framed structures.
Termite Problems with Wood-Framed Construction
Wood-frame construction is prone to termite problems, which can damage a building’s durability and cost thousands of dollars in repair. Termites are a particular problem in warmer climates: the south, southeast, west, and southwest of the United States (U.S). However, there are termites in every U.S. state but Alaska. It is essential during the planning and design phase of a wood-framed building to include termite protection in the construction phase. However, termite protection application during construction is challenging and requires specialized equipment and a trained professional. Preventing termites from attacking a building is essential to maintaining the integrity of a structure. It can also save building owners money down the road. In fact, the annual estimated cost of termite damage and control measures in the U.S. is $5 billion.
Disaster Resistance of Wood-Frame Construction
Ensuring that a wood-framed structure has the strength, durability, and resilience to resist storms, flooding, tornadoes, hurricanes and even earthquakes is challenging and expensive. In earthquake prone areas, anchoring a building’s foundation is essential to avoiding structural shifts and the threat of water seepage. In tornado and hurricane prone areas, builders must follow strict building code standards to ensure a minimum level of resistance to wind loads and a continuous load path***** to the ground. Also, the walls, roofs, windows, and doors must be missile resistant (flying debris). Without this resistance, there can be significant damage to the building’s envelope. Constructing a disaster resistant wood-framed buildings is possible; however, it can cost 25–30 percent more than standard construction.
There are other, less significant challenges to wood-frame construction. Wood-frame construction often requires a lot of resizing and shaping of the lumber. This process creates much waste, along with a financial loss to the client. Another challenge is that wood framing has limited architectural styles and elements. It might not be possible to include large spans, cantilevers, and large and numerous windows in the design of a wood-framed building. Constructing a wood-framed building with adequate sound insulation is also challenging. While these challenges are not as serious as water, fire, insect and disaster resistance, they can be just as important to the client.
Avoid the Challenges of Wood Construction with Bautex Wall Systems
The Bautex™ Wall System solves or reduces many of the challenges of light-wood-frame construction. Bautex Blocks are moisture-resistant, fire-resistant, pest-resistance and disaster-resistant. Also, Bautex Blocks are noise-reducing, low-maintenance, pest resistant, energy efficient and healthy. The benefits of concrete construction make Bautex Wall Assembly a smart material choice for today’s builders. Also, Bautex Block buildings are aesthetically pleasing and flexible in their design options. Bautex Block buildings are an excellent choice for builders who want to avoid the challenges of wood-frame construction.
- Bautex Block Wall Assembly is Disaster Resistant. Bautex Block Wall Assembly meets the FEMA 320 and FEMA 361 guidelines in storm zones with possible wind speeds up to 250 miles per hour. The Bautex Blocks also meet or exceed ICC-500 and FEMA standards for debris impact.
- Bautex Block Wall Assembly is Energy Efficient. Bautex Block Wall Assembly creates an energy efficient building envelope that is compliant with the latest building codes. Bautex Block wall provide an R-14 continuous insulation; far exceeding 2015 IECC recommendations for mass wall assemblies.
- Bautex Block Wall Assembly is the Healthy Choice. Bautex AMB 20 air and moisture barrier applied to the block wall prevents air and moisture infiltration to the interior of a home. Preventing wet and damp spots in a home is vital to stopping the growth of mold. Mold is a problem because it produces allergens and irritants. Touching or inhaling mold or mold spores may cause allergic reactions in some individuals.
- The Bautex Block Wall Assembly Keep Noise Outside. The Bautex Wall System reduces the transfer of sound from the outside to the inside of a structure. In fact, the Bautex Wall System received a high Sound Transmission Class (STC) rating of 51 and a high Outdoor-Indoor Transmission Class (OITC) performance rating of 47.
- Bautex Insulated Concrete Block Walls are Fire Resistance. Bautex Block Wall Assembly meet and exceed industry's standard for fire resistance. They have an ASTM E119 fire rating of four-hours (twice the two-hour requirement), and an ASTM E84 reported values for flame speed of zero and smoke development of twenty. Because the blocks meet the E84 and NFPA 286 they essentially meet the NFPA 101 code.
There are many challenges to light wood-frame construction including moisture, fire, insect and disaster resistance. Also, waste, acoustics and design limitation can be problematic to contractors. An alternative to light-wood-frame construction is insulated concrete block. Insulated concrete block is disaster-resistant, energy-efficient, fire-resistant, noise-reducing, pest-resistant, low-maintenance, and healthy. Architects, contractors, and building owners can avoid the challenges of wood-frame construction by choosing insulated concrete block as an alternative to light-wood-frame construction. For more information on the challenges and solutions to wood-frame construction visit Bautex Wall Systems.
*Light-wood construction is used for framing, fastening, foundation laying, truss-framed and plank and beam construction for new construction, remodels, maintenance and repairs, and additions.
** Platform framing is a light wood-frame construction method. Each floor in platform frame construction is framed independently by nailing the horizontal framing member to the top of the wall studs.
***Wood (cellulose) is composed of carbon hydrogen, and oxygen (cellulose formula is C6H10O5). When combined with oxygen and heat, wood will burn.
****Buildings are especially susceptible to fire damage during construction prior to placing fire protection over the frame. For example, March 25, 2014 in Houston, Texas an apartment building went up in flames during construction; https://www.youtube.com/watch?v=9N-eH4GbbJg
*****A continuous load path is the best defense towards holding a building together during high winds. A load is a force acting on a building. The continuous load path ensures that when a load, including lateral (horizontal) and uplift loads, attacks a building, the load will move from the roof, wall and other components toward the foundation and into the ground. The purpose of a strong continuous load path is to hold the roof, walls, floors, and foundation together during an extreme wind event.