What is that stuff in my walls that has brown paper on it? That is fiberglass batt insulation. The brown kraft paper is a vital part of it. It creates a vapor retarder. The vapor retarder helps reduce water vapor transferring from the interior of your home (the warm side) to the exterior (the cold side) where moisture could build up and create havoc in your home. There is debate as to its functionality but it is required as per International Residential Code 2015 NJ Edition Section R702.7 Vapor retarders.

Insulation has a history going back to ancient Egyptian days when mud bricks were used to control interior temperatures. The insulation in your walls today, the pink stuff (most common color), is just that, insulation and is classified by R-value. It is composed of resin and very fine glass woven strands. It is a material to resist heat flow and in simplistic terms the bigger the number the better the insulating power. It used to be enough to have a 2×4 stud wall exterior and fill it solid with R-13 batt insulation; however, with the International Energy Code in effect, it is not possible anymore to have such an exterior wall for your home. New Jersey switched to the IECC back in 2007 and has adopted updates along the way. If you build with 2×4’s you will be required to also wrap the exterior with a continuous rigid insulation (with a value of R-5) or you can go with a 2×6 exterior wall and get R-19 or R-21 batt insulation and be able to conform to the governing code requirements without wrapping the outside. There are many other factors that impact these numbers but as a baseline, this is a good rule of thumb. The US Department of Energy notified New Jersey that by the year 2030 due to this and other techniques will save nearly $195 million annually in energy costs.

You may ask yourself how much R-value my winter coat has. Well, clothing has a different method of calculating warmth. The clothing industry uses the “clo” unit of measurement for warmth. This standard is based upon the insulation required to keep a resting person warm in a windless room at 70°F which is equal to one clo (the value of 0 clo equals being naked!). Guess what? You can convert “clo” units into R-value by multiplying by .88. To keep yourself warm outside on a cold winter day you typically layer your clothes and if you are sporting about a 4 in clo you are probably warm.

I am glad spring is here!