Mold is a common problem in buildings that affects human health and can also damage or destroy building materials. Because mold requires water to grow, controlling mold requires a thorough understanding of how water enters and travels (or doesn’t) through buildings. Because mold also requires a food source, controlling it also requires an understanding of which building materials are susceptible to mold and how best to use and protect them.
The following documents address these key issues of water movement and mold-susceptibility. They also discuss important topics such as health effects, mold testing, and what to do when mold is found.
Today’s houses make it easier for mold to find the food and water it needs to thrive. The cure is a quick cleanup and smarter choices in materials. Reprinted with permission from Fine Homebuilding, December 2006/January 2007, pages 70-75.
How water gets into a structure, why it doesn’t leave, and how these architectural flaws become HVAC headaches. This two-part article was first published in HPAC Engineering, December 2001 and January 2002.
This article answers your questions about mold, what it is, where it grows, how it spreads, how can I prevent it.
Although this article is titled "Mold Testing" it actually tells you why testing for mold is usually not needed.
This article provides both general guidelines for mold remediation as well as specific guidelines for the typical locations where mold is most often found in houses.
This article briefly repeats some of the information in the other mold articles but also includes information on how to prevent mold in residential structures.
The construction and operation of buildings consumes over a third of the world’s energy consumption, and 40% of all the mined resources. Striving to make buildings more sustainable, while saving construction and operating costs and improving health and occupant well being is not only possible and practical, it should be the goal of the building industry. Achieving this goal requires an awareness of the problem and the skills to design, specify, construct, and operate buildings in a manner that is often quite different from current standard approaches. This digest will review the challenge of sustainability, discuss methods of assessing green buildings, and recommend a process by which more sustainable buildings can be delivered.
Moisture accumulates when the rate of moisture entry into an assembly exceeds the rate of moisture removal. When moisture accumulation exceeds the ability of the assembly materials to store the moisture without significantly degrading performance or long-term service life, moisture problems result.
Buildings used to be constructed over cellars. Cellars were dank, dark places where coal was stored. People never intended to live in cellars. Now we have things called basements that have pool tables, media centers and play rooms. Cellars were easy to construct – rubble, stone, bricks and sometimes block. If they got wet or were damp so what? Basements are different. They are not easy to construct if we intend to live in them. They need to be dry, comfortable and keep contaminants out.
Over the last 50 years there has been a notable expansion of living space. The useful conditioned space of building enclosures is expanding to the outer edge of the building skin (Figure 1). Attics, crawlspaces, garages and basements are valuable real estate that are being used to live in or used for storage or places to locate mechanical systems. Basements are viewed by many as cheap space that can easily be incorporated into a home. Keeping basements dry, comfortable and contaminant free is proving to be anything but simple.
Adding outdoor air in hot humid climates causes moisture problems right? Sometimes. It depends on the condition of the house before you start to add outdoor air. Contrary to popular belief, most houses in hot, humid climates are over ventilated due to duct leakage and induced air change from internal air pressure effects due to unbalanced air flow and door closure.
Water comes in four forms: solid, liquid, vapor and adsorbed. All four forms can cause grief to building owners, designers and contractors. When water causes building problems investigating and diagnosing the problem can be challenging because water constantly changes its form inside a building and within its materials. The investigator must hunt down the water thinking like water.
Air flow in buildings is one of the major factors that governs the interaction of the building structure with the mechanical system, climate and occupants. If the air flow at any point within a building or building assembly can be determined or predicted, the temperature and moisture (hygrothermal or pyschometric) conditions can also be determined or predicted. If the hygrothermal conditions of the building or building assembly are known, the performance of materials can also be determined or predicted
Are multifamily buildings one building or a bunch of individual buildings sharing the same structure? Should services and systems be shared or individual? The passions regarding these questions are as strong as those separating Yankee fans and Red Sox fans.
We learn our lessons from disaster. Hurricane Andrew taught us about wind. Hurricanes Charley, Frances and Jeanne taught us about rain. The Red River of the North Basin taught us about floods. Hurricane Katrina had it all: wind, rain and flood. That we will rebuild, and rebuild in the same place, is not in doubt. This is what we do – for better or worse. If we are to rebuild and if we are to rebuild in the same place how should we rebuild?
Moisture is involved in most building problems. The most serious tend to be structural damage due to wood decay, unhealthy fungal growth, corrosion, freeze-thaw, and damage to moisture sensitive interior finishes. Avoiding these problems requires an understanding of moisture, the nature of materials, and how it interacts with materials. This digest deals with these fundamentals.
Multifamily public and low-income housing have particular problems when it comes to moisture and air pollutants. In this first of a two-part series, we look at one particular type of multifamily construction: midrise housing. Originally published in Home Energy September/October 2001, pages 24-28.
An edited version of this Insight first appeared in the ASHRAE Journal. Spain gave Florida to the United States in exchange for the United States giving up any claims on Texas. Nobody really wanted to live there except the Seminoles until air-conditioning was invented.
An edited version of this Insight first appeared in the ASHRAE Journal. Buildings today are hollow and multi-layered with numerous air gaps or void spaces. Chases, shafts, soffits and drops abound. Everything is connected to everything else, typically unintentionally.
An edited version of this article was first published in the ASHRAE Journal.
I have loved bourbon for a long time. I like the history. And I like the independent spirit of the folks who make it, their sense of tradition, and their willingness to continue to experiment. Even now after two hundred years of history, they experiment mostly by trial and error rather than by computer simulations. I have often thought that if engineers were in the liquor business, bourbon would be the liquor they would make.
An edited version of this Insight first appeared in the ASHRAE Journal.
Think of the good old days—the Civil War, WWI, the Great Depression, WWII—crawlspaces were uninsulated. They were ventilated and they didn’t have ground covers—and they didn’t have problems. Why?
