Fabrica718 ‘s Julie Moskovitz, and the owner of the Park Place Brownstone, have been using the Pro Clima line of products to seal the most difficult junction at this Passive House project. This to meet the strict target they had set to meet the 0.6ACH50is the recommended airtightness as set for certification by PHI, even for a retrofit (although a 1.0ACH50 could pass too if one would seek Enerphit certification for a retrofit)
Let’s focus on a few areas that were addressed, from basement to roof in this renovation/new construction hybrid:
Basement slab to walls:
Under slab plastic is airtight and durably connected with CONTEGA FC to plastered concrete (new) and original rubble foundation.
Windows to brick (sealed) wall connections:
These notoriously leaky junctions are bridged with INTELLO Plus membrane, which was cut to size. This strong airtight layer was then face taped to the window-frames with TESCON Profil. All other connections were made with TESCON Vana, as you can see a change of direction of the membrane leads to the insertion of some small patched, to unsure the airtight layer is continuous.
Where the connection needed to be made to the sika/thorosealed walls, TESCON Primer RP was applied first to solidify the cementitous substrate and to assure a durable bond could be made to it with the Vana tape. Don’t forget to rub down the tape the entire length of the tape at least once when applying….
The one story addition (see drawing on Fabrica718’s website) has CMU party walls and a wood-beamed pitched roof. To properly seal it, a SOLITEX Mento membrane was taped to the wall before the joist were set. This enable them to flip it up over the rim joist while roof beams were installed, and down over these joist before plywood was mounted on them. This ensures an continuous airtight layer (remember that red pencil) in a spot that normally leaks like a sieve in conventional construction, after it is taped to the plywood and at all it’s junctions.
Blowerdoor test 2:
Jordan Goldman from Zero Energy Design, the Passive House consultant on this project, did a blowerdoor today. It was the second blowerdoor, the first one before most of the taping was done had already come in at app. 1.5ACH50. During today’s test the good news was relayed to us, that because of all the efforts of all people involved, including many hours of the owner taping his own windows, the house is testing below 0.58ACH50! Not bad at all for a retrofit. Persistence and meticulous air-tightness work pays off. Four Seven Five is happy to have been able to assist in getting the house this tight.
Some penetrations still need to be made (HRV, plumbing stack, solar connections), but if done properly (and with the right solutions to seal these) the airtightness shouldn’t get compromised to much and could actually improved as we did find some small leaks during today’s test…..