It has long been known that water has the ability to erode some of the hardest materials on earth given enough time but the mechanics of how this occurs has only recently been studied. At the University of Minnesota Twin Cities, researchers have discovered why small liquid droplets cause the erosion of solid surfaces. Using a new analysis technique called high-speed stress microscopy that measures the force and pressure exerted on a surface as a drop contact it, the researchers have discovered that the force of a droplet spreads out as the drop deforms itself on impact. This deformation happens faster than the speed of sound, unleashing a shockwave along the surface of the solid object: “Each droplet behaves like a small bomb, releasing its impact energy explosively and giving it the force necessary to erode surfaces over time”. This discovery is expected to help material developers and engineers create better erosion-resistant coatings and materials that weather the elements better than current systems.
Metal guardrails can provide stylish, long-term fall protection for balconies, walkways, garages, and many other elevated structures. While metal guardrails can last almost twice as long as wood guardrails, periodic maintenance is still required to ensure they remain serviceable and do not pose any life-safety hazards due to deterioration of the aging railing components. A few steps taken every few years can allow these vital building components to last well into the future of the building:
Understand your railings. Are they aluminum or steel? Do they have a protective coating such as a powder coating? Are they surface mounted or embedded into a concrete slab? The answer to these questions and many more are crucial to determining exactly which approach is best for maintaining your railings!
Routine cleaning of the guardrails will help remove built-up organic growth and other stains that could contribute to deterioration of the railing finishes.
Make sure water has a way to get out of the railings. Many times, these railing systems are comprised of numerous hollow tubes which can trap water that enters the railings through cracks or holes or from condensation build up. The placement of weep holes throughout the assembly and especially at the post bases can help evacuate water from the railing interior, reducing the potential for corrosion of the metal.
Restore protective coatings. Peeled/missing coating will expose the underlying metal member to elements, exacerbating corrosion at these areas. Recoating railings will ensure this protective cover between the metal and the environment will remain effective.
Clean corrosion as soon as possible! It is imperative to clean corrosion from steel members before it progresses to section loss. If holes start appearing in the guardrails due to corrosion, more intensive repairs measure will be required, including replacement of the member.
If you are looking for a professional evaluation of your building’s railings, ETC can provide the evaluation services you need.
As construction techniques continue to grow and evolve, choosing the right material for your job may seem a little overwhelming. This especially rings true with timber construction. Gone are the days when you just needed to specify the size and tree species. Here’s a guide to help you choose the timber that is best suited for your job.
Sawn Wood‐ Traditional sawn wood is still the commonly used type of lumber. Almost all structural sawn wood beams originate from softwood tree species, such as Pine or Douglas Fir. Structural sawn lumber is further classified through stress‐gradings, which establish standard working values for properties that can be used to determine the load‐bearing capacity of these members. Typical lumber grades can be seen on the adjacent table. Traditional sawn lumber can be used for almost all structural member, such as joists, beams, posts, etc.
LVL Member
Laminated Veneer Lumber (LVL)‐ Laminated veneer lumber belongs to a family of engineered wood products called structural composite lumber (SCL). Structural composite lumber members are comprised of blocks of lumber materials know as “billets”, which are veneers, strands or flakes of dried and graded woods adhered together. For LVL beams, thin wood veneers are bonded together into a billet, with the grain of all veneers running parallel to the length of the beam. Called “parallel lamination”, this orientation allows LVL beams to exceed the load‐bearing bearing capacity of similarly sized sawn lumber and be used for long‐spanning load‐bearing members, such as beams or rafters.
PSL Member
Parallel Strand Lumber (PSL)‐ Parallel strand lumber, another type of structural composite lumber, is manufactured using long, thin strands of wood (typically the waste material from plywood manufacturing), which are laid parallel and bonded together to form a billet. Similar to LVL members, PSL members can be used for long‐spanning beams where greater load‐bearing capacity is required. Additionally, PSL members are also frequently used as columns.
Laminated Strand Lumber (LSL)‐ Similar to PSL, laminated strand lumber is comprised of long, flaked wood strands of hardwoods not normally used for structural applications (e.g. maple). The wood strands used for LSL are typically shorter and thicker then those used in PSL, leading to lower load‐bearing capacity. Typically, LSL members are used for wall framing, such as studs and headers. LSL members can also be used for intermediate spanning beams and rim boards, where the higher strength LVL or PSL members are unnecessary.
LSL Member
Oriented Strand Lumber (OSL)‐ Oriented strand lumber is comprised of flaked wood strands strands very similar to those used in LSL member, but the length of the strand has been reduced and the thickness increased. As such, OSL members can typically be used in similar situations where LSL members are utilized
The trademark of a good wall cladding is its energy efficiency and watertightness. A home or building that is impervious to nature’s elements is a long-lasting, secure investment. For an in-depth look at the multiple layers and benefits of EIFS, Host Joe Shuffleton speaks with Certified Exterior Insulation Finishing System (EIFS) Inspector, Trey Parsons. Trey received his certification from the Association of the Wall and Ceiling Industry and has over seven years of experience. During the discussion, Trey reveals the installation process of EIFS, the different ways proper drainage can be achieved, and how to recognize issues with existing installations.
In this episode:
[1:23] Trey describes the process of becoming certified by the Association of the Wall and Ceiling Industry.
[2:47] Exterior Insulation and Finish System (EIFS) has been known by many other names in the past.
[3:42] Trey explains the process of installing wall cladding, providing each step in detail.
[6:45] In Trey’s experience, he sees vertical trowel lanes used for drainage in EIFS.
[7:57] Do finishing top coats provide a weather-tight configuration?
[9:29] The three main types of joints associated with EIFS.
[12:39] The difference between stucco and EIFS.
[14:25] Trey describes the history of EIFS in the United States, issues found in early installations, and why it is still a preferred wall cladding.
[18:32] Building codes, common practices, and how to recognize possible issues with EIFS.
[21:48] Repair or maintenance of EIFS wall cladding requires a qualified contractor with EIFS experience.
