BUILDING A NEW “GREEN CHURCH” INTERIOR!!

     It is said in the construction trades that it’s difficult to make changes and that trades get set in their ways…..unfortunately, it is true in many cases, especially among older tradesmen. While this older licensed tradesman learned long ago to look towards the future, using metal studs in a home assembly has not been on the list of products to use; it is now.

    As has been noted, our intent is to renovate with cost and energy efficiency in mind, along with responsible efforts on conservation.

    When we sat down with our energy auditor on the “green church” project, Marty recommended metal studding. After some research, I am prepared to give them a try. There are multiple reasons for my change of heart.  Steel studding is 100% recyclable and the overall percentage of steel being recycled is close to 60%. One study stated that framing an average home with steel studding uses up about six old cars and saves from 40 to 50 trees. Recycled steel studs are not affected by rot; they remain straight and there is no shrinkage.  California requires that multiple occupancy buildings must be constructed of non-combustible materials and some insurance companies recognize this fire rating, offering discounts for metal framed homes.

     In our drive to renovate with the planet in mind, another factor was noted. Unless the contractor is very diligent in their recycle efforts, an average wood frame home generates about 50 cubic feet of landfill waste. Steel studded homes generate about 1.5 cubic feet of waste and are 100% recyclable. On the other hand, some argue that the production of steel is not carbon friendly. While there is merit to this comment, since 1972 steel manufacturers have reduced the energy needed to produce steel by nearly 30%; granted, there is still a ways to go.


    Since we plan to build a “building within a building,” the weight factor is a consideration and steel studding weighs about 40% less than wood.  At the same time, it is, in fact, stronger. With 12’ high walls, strength and keeping the walls straight are primary considerations.

    Building with steel studs has two main components, the base track and the stud. The edge of the stud is called the flange and the wider, flat portion, the web. The steel stud walls will be assembled in sections so that both sides of the stud can be screwed into the base track. They will then be raised up against the existing walls, levelled, then secured to the wall. Once secured, the base track will be screwed to the floor. Due to the fact that the church has an angled wall portion at the top, a custom jig to fit the second section above the main wall had to be developed. This jig will hold the two steel stud sections together while we spray foam the space behind the vertical and angled wall. The major benefit is the addition of a continuous air barrier or, should I say, as continuous as possible. In a few weeks, once this process begins, we will photograph how this is done.

    While ours is an open concept space, I have had a couple of readers following this series ask how an existing home with numerous walls/rooms could be retrofitted in this way. By opening up the end of the internal partitions, thereby allowing the new framework, a similar installation could be done.

    For a number of reasons, we have chosen Roxul as the insulation of preference. Roxul makes a batt especially designed for steel stud assembly that is slightly larger than the batts used with wood. It fits with the conservation idea in that it is made from lava and reclaimed slag and is known as the “stone wool” insulation.  There was some initial concern in regard to vapour permeability, since the new wall will be fitted against a plaster wall filled with wood shavings. However, when we shim to make the walls plumb, a small air space will be created. As well, Roxul allows transient vapor to pass through, increasing the potential for drying of the walls, including the “wood shavings insulation” that is already present. Roxul does not wick water and has excellent flame retardancy. Because we are creating an entire internal envelope with steel and Roxul, our home insurance broker intends to talk to our insurance provider about a possible discount on insurance rates.
 

    My biggest concern was Roxul’s stackable strength and, after a chat with a company rep, my concern was alleviated, as it is actually a semi-rigid application. Provided we fit them correctly and follow instructions, the 12 foot high walls will not be an issue. Roxul is easily cut with a serrated knife. It is important to take the time to fit around wall switches and plugs, as trying to add in low pressure spray foam will not work. Its flexible edge will allow us to compress the batts into the metal studs, after which the Roxul will spring back to fill the cavity. There are two kinds of Roxul batts, Safe’n’sound and Comfort Batt. We will be using the comfort batt in this renovation. This one is available in widths for steel studs.  Framing with six inch steel studs and using the R24 steel stud Roxul, coupled with the existing R12  that our energy auditor calculated, we will have a wall upwards of R38; a far cry from the 1894 standards.

    To enable us to report on the “Green Living Show” that was just held in Toronto, we will be taking a break from this series for a couple of weeks. It is always an excellent show with numerous new “green” products and ideas. Maybe even something to teach this old dog some new tricks for the current project!  Stay tuned and catch any missed columns at www.alltechgreenchurch.ca