ONE TON SACK                                                                             Greenbuilders Newsletter No. 3               “We thought our bagging operation would be running by now” said the voice at the other end of the line.  “But it isn’t.” There was a silence.  I had ordered two tons of engineered dirt for a small residential green roof.  My supplier had promised it would be delivered to his warehouse in Baltimore in fifty pound bags.  More than a handful, but manageable with a crew.   I had a crew of sturdy souls available and I pictured them trundling through my project to the third floor and out the tiny window onto the roof, fifty pound sacks in hand.  Sort of a sorcerer’s apprentice effect.  Now there was to be no trundling. Green roofs in the United States have been primarily large commercial or public projects.  The supplier I was talking with had been trying to develop a market for smaller residential projects.  To do this, he had to persuade the manufacturer in Philadelphia to produce my two tons while they were doing a much larger project for an office building in New York City.  My order was a sort of afterthought in a landscape of cranes and flatbed trucks. “The good news is that they’ve made your dirt” said my supplier apologetically.  “But it is in one ton sacks and it is in Philadelphia.  I think I might be able to get it to Baltimore, but I don’t know how to get it off the truck, unless you have a crane?” My current project is big to me – an addition and whole house renovation in a quiet residential neighborhood, but no, I do not have a crane. Furthermore, I run a business.  I have deadlines and budgets.  Strange supplier phone calls are not in my management plan.  I gulped and then recommitted to this particular green component.. So, we worked it out.  The supplier heroically persisted until he found a delivery method.  I borrowed a laddervator from my kindly roofing contractor.  A laddervator is a ladder with a conveyor belt and a platform which roofers use to get shingles onto a roof. Early one morning a gigantic gleaming steel dumptruck tiptoed down our street, deposited a small pile of dirt at the curb, and drove away.   Small until you try to move it in five gallon buckets, and then it takes a while.  A few hours later, though, we had our potential green roof. Green roofs come in two types, intensive which has a deep layer of dirt and you can plant trees in it, and extensive which uses a layer of special light dirt (containing bits of lava rock).  An extensive green roof is only 4- 6 inches deep and you plant sedum or other low maintenance cover.  The clients and I had a great time on a hot August day driving out to Emory Knolls Farm (greenroofplants.com) to choose our plants.  Though low and simple, they do flower and produce a subtle harmony of color and texture. Our roof was created of a high density (root-resistant) rubber membrane roof, installed as usual except for a parapet around the edges.  No gutter, but you do need at least a slight slope and drains and downspouts at the corners.  On top of the rubber membrane goes a layer of heavy fabric, plastic drainage plates, and a second lighter layer of fabric.  Resource Conservation Technology ( ) advised me on the design. A greenroof reduces runoff, mitigates the “heat island” effect which makes downtowns so uncomfortable in summer, and provides some insulation value. When I was in my twenties, I taught math for a year or so in Oakland inner city schools.  One of the kids pegged our program exactly.  “White teachers come here because they think we’re cute” he said.  “When they find out we’re not, they get mad.”   Building green can quickly lead to questions and concerns about any technique one may select.  Whether running a business or running a house, we have lots to do other than making a new technique work.  However, my clients hung in there with me, and I paid a few hundred dollars I didn’t mean to for that gleaming dumptruck.   I climbed onto the roof in the middle of a stormy night to discover that someone had left the laddervator where it blocked our carefully constructed drainage system.   When the clouds cleared, the plants arrived, along with an enthusiastic and knowledgeable volunteer checking out green roofs so she could put one on her house nearby. We got on the roof with gloves and trowels.  It was one of those gorgeous Maryland fall days without equal, clear and slightly warm at least at the level of a third floor rooftop.  I should have been checking on my workmen.  But I stayed and we chatted and planted.  We went for creative rather than a geometric design, scattering our tiny plants where whimsy dictated. After a bit, we stopped, looked around, and said to each other:  “This is good work we have to do.  How fortunate we are.  How lucky.” Photographs and more information on green roofs.                                                                    Home