Masonry walls are generally highly durable. However, when masonry walls in cold climates stay too wet for too long, freeze-thaw damage can occur. This issue has particular relevance for energy efficiency retrofits, because the addition of interior insulation causes the masonry to stay colder and have a lower drying potential.
The following documents present details of BSC’s research and experience regarding the prevention of freeze-thaw damage in retrofit projects. Technical topics such as the critical degree of saturation (Scrit) are discussed, and case studies and recommendations are provided.
An edited version of this Insight first appeared in the ASHRAE Journal. To claim that something that has holes in it can act as a water control layer is a pretty interesting argument. It is both true and untrue.
An edited version of this Insight first appeared in the ASHRAE Journal. Seventeen years ago we bought an old house—a fixer upper—over a hundred years old—in Westford, MA. I was going to make sure it would end up energy efficient.
An edited version of this Insight first appeared in the ASHRAE Journal. The Parthenon was constructed around 450 B.C. as a temple to the Goddess Athena. More recently a temple overlooking Vancouver was constructed by the contractor Gauvin the Younger to honor the God of Building Science Hutcheon. For the past five years the Devout have been sprinkling water on the temple Icons carefully watching the results.
An edited version of this Insight first appeared in the ASHRAE Journal. Engineers are pretty funny people. Engineers say that 1 inch of water exerts a force of – wait for it – 1 inch. Yup, 1 inch of water weighs 1 inch of water. It’s a gift we engineers have. Let me help you all out a little bit here, go suck on a straw and draw 1 inch of water up into the straw.
An edited version of this Insight first appeared in the ASHRAE Journal. It was the ants that finally did it. It wasn’t the shingles that needed to be replaced. It wasn’t the three-dimensional airflow network in the roof assembly. It wasn’t the lack of racking resistance. It wasn’t the lack of thermal resistance. It was the ants. Carpenter ants. There were just too many ants in my renovated barn.
Condensation within walls during cold weather is a common performance problem. Most such condensation is due to air leakage, not diffusion. Although air barrier and vapor control layers can reduce the quantity and occurrence of condensation due to both mechanisms, the use of exterior insulation (even if that insulation is a vapor barrier and/or air barrier) can warm sensitive surfaces within a wall and thereby eliminate or reduce condensation risks. This digest provides the background for designers to select the insulation levels need to reach specific levels of condensation control.
An edited version of this Insight first appeared in the ASHRAE Journal. Imagine a three-dimensional molecular billiard game with billiard balls that are sometimes sticky, and where the rules depend on where you are on the table. Then assume that there are many different types of tables and pockets of different sizes.
An edited version of this Insight first appeared in the ASHRAE Journal. One of the more difficult questions regarding enclosures is can we insulate the interior of a mass wall in a cold climate without causing damage from freeze/thaw cycles? The answer is usually yes, we can insulate. But, and there is almost always a “but,” it depends.
An edited version of this Insight first appeared in the ASHRAE Journal. Ice dams happen when the outside temperature is below freezing, the roof deck temperature is above freezing, and there is snow on the roof. The warm roof deck causes the snow on top of the roof deck to melt, and the melt water runs down to the edge of the roof where the water freezes leading to a buildup of ice and a backup of water, hence the term “dam."
A concise history of the improvements to traditional buildings through design and materials.
An edited version of this Insight first appeared in the ASHRAE Journal. It’s pretty easy to deal with new basements. If you want a challenge try dealing with century old houses sitting on top of rubble foundations. These houses are not going away and sooner or later we are going to have to fix them and insulate them.
An edited version of this Insight first appeared in the ASHRAE Journal. Five fundamental changes to building construction have occurred in the last 50 years – they happened so gradually, so insidiously that we missed their enormous significance.
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. Stucco was once viewed as a cladding system that solved moisture problems—it is now viewed as one that causes moisture problems. What happened?
An edited version of this Insight first appeared in the ASHRAE Journal. Mold is pretty easy to understand. No water no mold. Any questions? Well, there are a few. For one we have more mold today, but we don’t have more water. What’s with that?
An edited version of this Insight first appeared in the ASHRAE Journal. Sometimes things are so obvious we miss them. The Second Law of Thermodynamics is like that. Most of us get the heat goes from warm to cold thing. It’s the other simple applications of the Second Law that we miss.
The American Foursquare, a Sears, Roebuck & Co. kit home, was a staple of small American towns between 1908 and 1940. More than 100,000 of them were built in America. Homes built prior to 1980 make up 80% of the housing stock in the United States, and are responsible for a majority of the residential energy use in the country. All of the renovations used systems engineering principles to ensure good indoor air quality and longterm durability while providing deep energy reductions. This posting is permission of ASHRAE. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.
An edited version of this Insight first appeared in the ASHRAE Journal. You have got to love salesmen. They figure things out way before physicists, usually before engineers and certainly before greenie weenies. They found, what we should all know, that it is much more cost effective to fix the enclosure so that the actual system that you need is small and therefore does not cost much to install and does not cost much to operate. Oh, by the way, this approach also saves energy. Who knew?
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.
This digest will begin with a brief description of the system and materials, review moisture problems in buildings, and summarize how moisture control should be dealt with in strawbale buildings.
