A Brief History

The project entails repairing the building at 335 Maplewood Ave in a manner that meets both preservation and sustainability goals. The building is the new location for Petersen Engineering, a firm that has been located in Portsmouth since 1992, and specializes in sustainable building engineering. We intend for this project to showcase techniques & materials that promote both preservation and sustainability and intend to share all aspects of the project locally and regionally through open houses, presentations, industry tradeshows, case studies and publications. We foresee this project being a valuable educational tool to demonstrate that preservation goals need not be compromised by sustainability goals. We have teamed with Bruss Construction who we know from past collaborations has exceptional experience and expertise on projects with the dual goal of preservation and sustainability.

The project received approval by the Historic District Commission on January 6, 2010 with construction scheduled to begin early February 2010.

The projected peak heat loss reduction is 85%.

Friday, October 22, 2010

Basement digging complete!

The basement digging is complete! Woo Hoo!
I want to give proper credit to the team of workers from Diamond Staffing that did most of the job. (Labor Ready was on site for the first 2 days (I blogged about them) and then we switched to Diamond Staffing whom was on site for the remaining 6 days.) They really did a great job. I have a lot of respect for how hard they work.

The next big step in the basement is to address a few weak looking areas on the foundation walls, we might or might not need to do some reinforcing. We are consulting with Jeff Nawrocki from JSN Associates regarding what we should do. Hopefully everything is OK. Once the walls are cleared, we are going to lay down landscape fabric, roll out perforated pipe for perimeter drainage, lay down about 6" of crushed stone, put our insulation on top of the stone, roll out a vapor barrier membrane on top of the insulation, and then pour a 4" concrete slab on top of that. There are still lots of things to do! When all is said and done, there will be 6'-6" clearance to the bottom of structure throughout the basement.














On a seperate note:




I observed this frost on our roof yesterday morning. Notice that there is no frost around the plumbing vent (aka the stink pipe) and around the chimney. The plumbing vent is made of copper (conductive), I suppose that makes sense. It is a big thermal bridge. The chimney is a little bit more intriguing. Brick is conductive no doubt (about R-0.15/inch) but that is a big bare spot! There is no blocking around the chimney, it is completely wrapped in foam. There is no thermal bridge around the chimney except for the chimney itself. I wonder if there is no frost around the chimney because of conduction from the warm building, from stored thermal energy from the day before that kept the chimney warm overnight or if as the sun rose it heated up the chimney enough in the morning to begin radiating energy to melt the frost before I showed up to work. Maybe it is a little of everything. However this happened, this image is a good example of radiation heat transfer. How else would that frost be melted 2' away? Conduction through the shingles? I doubt it.

I guess we will never know...
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1 comment:

  1. Hi Ryan--just a thought on the frost patterns around the chimney. The roof sheathing is probably being cooled pretty well by night sky radiation (especially if it was a cold clear night prior to this picture). The degree of night sky radiation depends on the "view factor"--how much of the sky (vs. other buildings, chimneys, etc.) a piece of the roof "sees". This is why the side of your car facing away from the house might have dew on it in the morning, but not the side facing the towards the house. Just a thought. -Kohta from Building Science.

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