As experienced designers, contractors, and owners know, most paint and coating problems are correctable, but some are especially stubborn to address. The following is a partial compendium of typical failure modes and methods for addressing the problem, as provided by paint and coatings manufacturer Benjamin Moore & Co. (www.benjaminmoore.com):
1. Surface imperfections.
There are many types of imperfections that can be visible on painted or sealed surfaces. Alligatoring occurs when the paint film takes on the appearance of alligator hide. (A similar problem is known as wrinkling, which appears as a rough creased or crinkled pattern.) Alligatoring usually occurs when a topcoat is applied before an undercoat is dry, or if an alky enamel or other hard, rigid coating is applied over a latex primer or another more flexible finish layer. Some oil-based coats will lose elasticity as they age, causing this familiar cracking pattern.
Blistering (or bubbling) is caused by a localized loss of adhesion and lifting of the paint film from the underlying surface, sometimes when solvent gas expands on sunny façades. Blistering tends to occur in fresh coats of paint.
Both problems require removing as much paint as possible and repainting. However, blistering can immediately reappear if the problem is caused by moisture; to mitigate this problem, the contractor should repair loose caulk and retrofit drainage and drying details, if possible. Installing vents or exhaust fans can also reduce moisture by evaporation before it wets enclosure materials.
For alligatoring, most paint contractors will recommend completely remove the existing oil paint by using a heat gun, scraping, and sanding. After priming the reworked surface with a high-quality latex or oil-based primer, the area can then be recoated with exterior latex or similar paint.
3. Flaking and chalking.
In some cases, a painted or coated surface will exhibit a loose powder or flaking surface. These problems are caused by decomposing paint and are different from efflorescence or mottling, which display white, crusty mineral salt deposits that have leached from mortar, concrete, or masonry surfaces behind the paint. A similar problem known as frosting is often seen on dark paints and coatings; in this case, a white discolored substance appears on the surface, similar to salt staining.
Chalking paint may be washed by rain and cause patterns, or it may wash across other surfaces, an effect called chalk rundown.
4. Miscoloring and staining.
Other sources of miscoloration on exterior and interior surfaces include nailheads and other penetrations that leach a rust-colored stain onto a surface, which often trails down from the location of the hardware. Mildew appears as black, gray, or brown spots or areas on the paint film or caulk bead.
5. Surfactant leaching.
Another source of undesired color change is surfactant leaching, in which concentrated, water-soluble ingredients in latexes seep to the paint surface, often creating a brownish blotchy or shiny appearance. Tannin staining can also be a brownish or tan discoloration on the paint surface, caused by wood tannins that leach through the paint film.
When applied properly onto suitably prepared substrates, architectural coatings will rarely exhibit these kinds of failures. Even better, when integrated into a thoughtful sustainability program, paints and coatings can be a partner in effective building designs that promote improvements to project economics and social considerations as well as protecting the environment.
Student Housing | Mar 13, 2023
University of Oklahoma, Missouri S&T add storm-safe spaces in student housing buildings for tornado protection
More universities are incorporating reinforced rooms in student housing designs to provide an extra layer of protection for students. Storm shelters have been included in recent KWK Architects-designed university projects in the Great Plains where there is a high incidence of tornadoes. Projects include Headington and Dunham Residential Colleges at the University of Oklahoma and the University Commons residential complex at Missouri S&T.
AEC Innovators | Mar 3, 2023
Meet BD+C's 2023 AEC Innovators
More than ever, AEC firms and their suppliers are wedding innovation with corporate responsibility. How they are addressing climate change usually gets the headlines. But as the following articles in our AEC Innovators package chronicle, companies are attempting to make an impact as well on the integrity of their supply chains, the reduction of construction waste, and answering calls for more affordable housing and homeless shelters. As often as not, these companies are partnering with municipalities and nonprofit interest groups to help guide their production.
Codes | Mar 2, 2023
Biden Administration’s proposed building materials rules increase domestic requirements
The Biden Administration’s proposal on building materials rules used on federal construction and federally funded state and local buildings would significantly boost the made-in-America mandate. In the past, products could qualify as domestically made if at least 55% of the value of their components were from the U.S.
AEC Innovators | Mar 2, 2023
Turner Construction extends its ESG commitment to thwarting forced labor in its supply chain
Turner Construction joins a growing AEC industry movement, inspired by the Design for Freedom initiative, to eliminate forced labor and child labor from the production and distribution of building products.
AEC Innovators | Feb 28, 2023
Meet the 'urban miner' who is rethinking how we deconstruct and reuse buildings
New Horizon Urban Mining, a demolition firm in the Netherlands, has hitched its business model to construction materials recycling. It's plan: deconstruct buildings and infrastructure and sell the building products for reuse in new construction. New Horizon and its Founder Michel Baars have been named 2023 AEC Innovators by Building Design+Construction editors.
Codes and Standards | Feb 8, 2023
GSA releases draft of federal low embodied carbon material standards
The General Services Administration recently released a document that outlines standards for low embodied carbon materials and products to be used on federal construction projects.
Concrete | Jan 24, 2023
Researchers investigate ancient Roman concrete to make durable, lower carbon mortar
Researchers have turned to an ancient Roman concrete recipe to develop more durable concrete that lasts for centuries and can potentially reduce the carbon impact of the built environment.
Standards | Jan 19, 2023
Fenestration Alliance updates liquid applied flashing standard
The Fenestration and Glazing Industry Alliance (FGIA) published an update to its Liquid Applied Flashing Standard. The document contains minimum performance requirements for liquid applied flashing used to provide water-resistive seals around exterior wall openings in buildings.
Sponsored | Resiliency | Dec 14, 2022
Flood protection: What building owners need to know to protect their properties
This course from Walter P Moore examines numerous flood protection approaches and building owner needs before delving into the flood protection process. Determining the flood resilience of a property can provide a good understanding of risk associated costs.
K-12 Schools | Nov 30, 2022
School districts are prioritizing federal funds for air filtration, HVAC upgrades
U.S. school districts are widely planning to use funds from last year’s American Rescue Plan (ARP) to upgrade or improve air filtration and heating/cooling systems, according to a report from the Center for Green Schools at the U.S. Green Building Council. The report, “School Facilities Funding in the Pandemic,” says air filtration and HVAC upgrades are the top facility improvement choice for the 5,004 school districts included in the analysis.