Installing linoleum or similar covering directly on concrete floors can be problematic if there is moisture in the slab. This is especially a concern with on grade slabs where there may be moisture under the slab that can permeate upward. Linoleum and similar floor coverings act as a barrier that can cause moisture to be trapped under the flooring. When this happens, the floor covering can unbond, warp and become a serious hazard.
Carpet covering will let moisture vapor pass through and normally are not a problem. Carpet can be a solution where other floor coverings are adversely affected by moisture.
If a linoleum or similar covering needs to be installed, it is important to understand and analyze the moisture present in and/or under the slab. Various types of moisture testing can be performed to help verify that the concrete is dry enough to allow the installation of an impermeable floor covering.
It’s hard to find a building today without concrete surfaces stained by rust. Rust stains can adversely transform the aesthetics of a beautiful building. How can rust stains be removed? Let’s find out!
Once rust staining has occurred, it is important to remove the stains without altering the color or finish texture of the concrete. Two techniques which can be implemented are dry methods (i.e. sandblasting, wire brushing, grinding, etc.) and wet methods (i.e. waterblasting, chemicals, etc.). If surface texture is not a priority, the dry methods can be a quick and cost-effective way to remove stains. If the final finish is important, as is commonly the case with architectural concrete, chemical treatments are recommended.
Mild stains usually can be removed with an oxalic acid or phosphoric acid solution, applied to a water saturated concrete surface. Deeper stains typically require a poultice, which absorbs the chemical solutions and then forms a paste over the stain. Older buildings require more attention with stain removal because the chemical treatments may remove other contaminants in the concrete, creating a lighter color than the adjacent concrete.
The rule of thumb when putting a cleaning solution on your stained carpet or clothes applies with concrete. Be sure to test different chemicals on small, inconspicuous areas to evaluate the treatment. Also, the longer you let a stain sit, the more difficult it is to remove, so seek help quickly when rust stains appear!
If you have decided to replace your deteriorated railings and/or windows with new, low-maintenance aluminum products, you may think selecting the coating color is the most difficult decision remaining. However, have you considered the coating performance of your new railings and windows?
Typically, coatings for these items fall under three (3) levels of performance as defined by the American Architectural Manufacturer’s Association (AAMA): Good Coating Performance (AAMA 2603), High Coating Performance (AAMA 2604) and Superior Coating Performance (AAMA 2605). Coating performance can be based on several factors, including coating thickness, color retention, gloss retention, coating erosion, chalk rating, humidity resistance and salt-spray corrosion resistance.
Specifying the coating performance largely depends on location, cost and exposure to the environment. Although having the superior-rated coating will provide the best long-term performance, it will be substantially more expensive, especially with a large railing and/or window replacement project. Unless the coatings are subjected to harsh environments (such as sunny coastal regions), the lower-grade coatings may meet your project needs.
To determine what coating performance option may be best suited for your project, members of our Architectural and Engineering staff are available to assist you. Developing architectural renderings with color and coating options are invaluable before undertaking such an important project.
On a recent project, we discovered a “scary” sight – an Exterior Insulation and Finish System (EIFS) that was not installed properly. The exposed wall revealed channelized white foam insulation, an inconsistently placed liquid waterproofing membrane applied on the sheathing, several different brands of materials, and incompatible asphaltic flashing to cover the building facade.
The manufacturer issued a warranty for a drainable system, but no weep holes were installed around the windows and doors to allow the water to drain. This cobbled together assembly is not only a problem for keeping the building watertight, but the warranty seems to be invalid.
This highlights the need for field inspections by Certified EIFS Inspectors (CEI) and installation by Certified EIFS Mechanics (CEM) and Contractors as designated by the AWCI (Association of the Wall and Ceiling Industry) to help ensure that the system is installed and performs as it was intended.
Preservative (pressure) treated wood is among the most common materials used in the construction of retaining walls. Ground-contact rated is standard for that use, but a GC label doesn’t tell the entire story. The important factor is preservative retention – the amount of chemical that remains in the wood after treatment, usually expressed as pounds per cubic foot or PCF. Optimum levels vary with the chemicals used and some products considered suitable for ground contact have retention levels that are less than desirable for retaining walls.
The American Wood Protection Association (AWPA) lists three categories for ground contact use, General Use (UC4A), Heavy Duty (UC4B) and Extreme Duty (UC4C). Heavy Duty protection would be suitable for most circumstances. Extreme Duty would be appropriate in such locations as freshwater lake or pond side walls. AWPA has separate categories for use in marine (saltwater) environments.
The timbers most used in retaining walls measure six by six or eight by eight inches in cross section and full preservative saturation is difficult to achieve in material that thick. Consequently, the central portions are less protected and decay (rot) can occur deep within the wood before there’s any visible evidence of distress. So-called Ground-Contact-rated, forty-year timbers can experience advanced deterioration within as few as fifteen years, while appearing sound.
In order to truly evaluate timber retaining walls it’s often necessary to sample the material by extracting full-depth cores with a specialty bit. Usually, a simple visual examination is sufficient to determine the level of degradation. Sounding (with a hammer) can reveal advanced decay. Rot reduces wood to dust, which will produce a hollow sound if sufficient wood has been compromised.
Dust clouds created while mixing concrete, jackhammering or cutting concrete sidewalks, tuckpointing, and sawing masonry blocks will soon be a thing of the past. The Occupational Safety and Health Administration (OSHA) will begin enforcing new regulations concerning worker’s exposure to silica dust on September 23, 2017. Silica dust is commonly produced when working with concrete, brick mortar, tiles, cement board, and many other common building materials. Long term exposure to silica dust can lead to the development of lung cancer, silicosis, and other permanent conditions with long lasting consequences. Because silica dust is so prevalent, the new regulations will impact many different industries including many facets of construction. Complying with these regulations will potentially impact, property owners, engineers, contractors, and other individuals, in many ways including the cost of construction work.
While there are many requirements detailed in the regulations, contractors will have to offer medical examinations to high exposure workers, implement engineering controls for silica dust, and develop procedures to limit the exposure to silica dust that workers experience. Depending on the circumstances and activity, engineering controls can include a vacuum system with a 99% efficiency for certain cases or water methods of controlling dust. Additionally, a HEPA vacuum may be required in certain cases and a personal respiratory protection device must be supplied to workers.
Building owners, project managers, and other individuals involved with construction need to be aware of the impacts that these new requirements can have on projects. Additionally, contractors may require cooperation from building owners and managers to be able to adhere to the new requirements.
More information regarding the requirements can be found at: https://www.osha.gov/silica/
Wood construction is no longer constrained to low rise buildings and single-family homes. New uses are emerging resulting from an expanded interest in wood with new trends impacting construction. Tall wood construction has resulted in multiple high-rise wood buildings around the world from the 14 story Treet Building in Norwayto the 18 story Brock Commons in Canada.
The interest in wood construction has led to office buildings, apartments, and commercial spaces being constructed out of wood. To support these structures, engineers have utilized advances in engineered lumber such as using glulam (glue-laminated timber), nail laminated timber, cross laminated timber, and other forms of engineered lumber. Engineered lumber is a strong wood based composite material that is often combined with special adhesives or other methods of fixation that can be used in columns, beams, and many other applications.
Renewed interest in mass timber has also risen because of the desire to construct tall wood framed buildings. It seems everything old is new again when you consider that the Old Faithful Inn was constructed in 1904 and is the largest log hotel in the world. The advances in wood engineering and higher levels of interest have resulted in investigations into potential changes to the building code that would allow taller wood construction. These trends indicate that the future of wood as a building material for both existing and new construction is exciting and filled with possibilities.
Researchers in Indonesia have developed a bendable concrete that is twice as strong as conventional concrete in bending, can be poured in thin slabs, and used for pavement. They hope that future pavement projects will be cast in a factory and slabs delivered to the job site. For information check out this link.