A Tale of Two Rooftops

14 02 2011

The snow on my rooftop is melting much more slowly than that on on the other houses, since my house keeps the heat in! And, note the beautiful new siding!


Air By-Passes…

19 01 2011

Ambrose, one of our DER gurus checking out the sidewall for bypasses

While you’ve got to have good air for your human lungs to breathe in a house, you don’t want to have uncontrolled holes letting air in and out, and giving an easy ride for lots of heat to exit and enter.  Air by-passes, thermal bridging and moisture penetration are anathema to a deep energy retrofit.  You’d think that with a superinsulated retrofit, we wouldn’t have an air bypass problem, but we did—because of the structure of the house. The rafters were sitting on 2×10’s laid flat across joists that protrude outboard from the sidewalls like the fins on a motorcycle engine (wierd metaphor, but that’s what they reminded me of).  Needless to say–a “chainsaw” retrofit–to keep a continuous air and water plane, became out of the question.

Joists above the southeast sidewall

Rafters and joists with structural plate in between

"Motorcycle fin" joists above southeast sidewall

"Crenellating" the rigid foam around each joist--2 layers worth...

Yes, we could have boxed everything in–but that didn’t happen. Instead, we spray-foamed the ____ out of all the air-bypasses at the joists (at least I hope we did…). And then used some nano-paint to try to “assuage” the conductive heat loss. I’m not sure the strategy really worked. An infrared scan will let us know soon enough.

Spray foam (closed cell) at the soffit joists

Nanopaint at joists but not at "joist-tails" that are just extending the roof eaves visually.

How we might have dealt with air bypasses and thermal bridging from the inside--if the attic sprayfoam had gone according to plan--see next post...

Trim and Foundation

5 08 2010

It has been raining most of the afternoon today – so Liane’s house, especially the windows, are getting tested for leaks. I’m sure all will be well since our hose test showed just how serious the Serious windows are when it comes to moisture penetration. The house is wrapped in its insulating coat and the roof is all finished, flashing included. All that remains is the siding and systems.

The sand has been moved to the side so that work on the new stairs may begin.

The hole where the new foundation will be poured.

We have to go 4' down!

The trim around the roof is finished.

And flashing is in place to divert water.

A hole is cut in the wall of the 3rd floor apartment to allow access to a future HRV.

Rick works on the access hatch.

New Roof!

28 07 2010

The new roof is looking great!  It should have a chance to prove itself tomorrow since we are expecting rain.

Look at that gorgeous roof!

Close up of the tiles. Notice how light they are: this will help reflect heat rather than absorb it.

Notice all the layers of the roof! All that extra stuff required extended rafters to support the new roof.

Joist and rafter "tails" extend the roof and resolve the fattened geometries of roof and walls nicely. Note the ends of the old attic joists sticking out--more on them later...

We actually had issues with leaky windows. But the problem had not been with the windows at all. The issue was with the detailing at the roof, particularly under the dormer and at the front bay of the house. Rick figured out the problem and reflashed properly. Thank you Rick!

We once had some back stairs...

...but they have been demolished and will be replaced by a much nicer wooden staircase.

Finished Windows

28 07 2010

The Serious windows have all been installed, and now it’s time to finish them on the interior: no more visible ice & water shields or house frame!  All the windows are fitted with Pressure Capillary tubes which are used to make sure that pressure between the panes of the window is equalized (they were manufactured at a higher altitude than where they have been installed).  This makes sure that the glass remains flat and doesn’t bow out.  The balloon at the end of each capillary tube should remain slightly inflated (not droopy) if pressure is equalized.

Finished window with capillary tube and balloon.

Instructions for the capillary tube.

Triple-pane Serious windows.

All done!

Work has also continued on the roof:

The plywood is nearly covered in the ice & water shield.

Left side of the roof: already has trim applied to the edge.

Right side: still needs trim and a little smoothing.

Nearly Done

24 07 2010

The work has been moving at a brisk pace, even through the heat and rain.  Currently, the roof is almost finished, the windows installed and finished on the interior, the site is getting cleaned up a little bit and preparations are being made for siding to be installed.

Second floor's porch has a nearly finished ceiling.

The guys shingle the remainder of the roof. The other side is already done!

Left over foam: Synergy will reuse it at another site.

Too Hot Today

7 07 2010

The temperature in Somerville (and Boston) soared to 100F on Tuesday!  The heat made it impossible to continue work, especially on the roof where the insulation reflects all that energy right onto the construction workers.  Even Laura and Darrell, the electrician, stuck to the shade while discussing the new electric needs for Liane’s house.

However, the exterior of the house is looking wonderful.  All the Serious Windows are installed, the house if wrapped in a warm, double layer of insulation, the strapping is applied, and the roof is nearly covered in plywood.  We love our hard working construction men!

Liane and Darrell discuss electricity and stay in the shade.

The first floor patio ceiling - all done!

The top window will block slightly less heat than the others so Liane will have a cozy corner for reading in the wintertime.

Our Serious windows!

The roof is nearly finished!

A close up look: notice the peak is wrapped in the same tape as the window frames to prevent moisture penetration.

Our pile of rigid insulation is nearly gone