Today was the last day of a 4 day online course with Joe Lstiburek on building science fundamentals that I attended. Below are my short-hand notes. Slides from the 4 day course can be found here for free.

Day 1

  • Keep the outside out and the inside in.
  • External and internal environmental loads
  • Plumbing code came first, then fire, then structure
  • Equation: 18-20 rise in temperature doubles the badness
  • The ASSEMBLY is far more important than the characteristics/changes of one component
  • Flow is from MORE TO LESS
  • Warm to cold = 1st approach
  • Water is going to be on the cold spot most of the time
  • TALK TO OLD PEOPLE
  • Buildings are still being built with negative pressure, vinyl wallpaper
  • Better not having a vapor control layer than having it in the wrong place
  • Thermal control layer as the least important layer, but has the most building codes because it’s the easiest the measure.
  • Drainage plane of ONE MM works if it’s CONTINUOUS. Brick association claims 2 inches (2”x4” used behind wall for mortar mess).
  • .5 water ratio in concrete to prevent bleed out
  • Corner connections = key = continuity
  • “Perforated” wrap = beware/don’t use
  • Vapor pressure is water vapor density
  • Moisture floating on warm air & warm air floating on cold air
  • 55 degrees = AC coil temperature (based on freon Thomas Midley & Carrier)
  • Plywood performs far better in drying (vapor permeable) than OSB
  • Wood is affected by relative humidity more than temperature
  • BRICK DIPPING should be done before laying brick to prevent water from getting sucked from the mortar into a dry brick
  • Rain screens to prevent hydrostatic pressure (WATER PRESSURE). Even 1/32 of an inch works.
  • Door flash pan back dam
  • SES spray foam recommendation

DAY 2

  • Back-painted siding (lower edge mostly) to prevent capillarity
  • Adsorbed water increases with relative humidity
  • 80% RH for mold to grow because of “capillary condensation”
  • Capillary condensation break with rough surface plaster coating (preventing mold growth on gypsum board)
  • Water phase change will release or absorb energy
  • Water at 32 degrees is both solid and liquid
  • MOLD IS GOLD
  • Accuracy of output is an good as the accuracy of the input
  • Concrete creep
  • Books: Roofs by Max Baker / Roofing Failures by Carl Cash / Building Science for a Cold Climate / John Straube books / Moisture Control for Residential Buildings by Joe Lstiburek
  • Small parapets protect roof edges to protect against vortices
  • Small parapet, white membrane, air and vapor control layers
  • Vented roofs are banned in high fire areas
  • Vented roofs blow off more easily in hurricane prone areas
  • Sealing perimeter between ceiling and wall before installing walls
  • Thermal resistance of wall should be same at upper perimeter (?)
  • 300 sq ft area = 1 sq ft of venting
  • 400 CFM for an AC unit
  • Vented balcony enclosures even in Florida
  • 1 degree difference in a vented attic means a lot between sheathing and rafter affects from moisture
  • Asphalt shingle blow off can mean nails losing strength
  • 20” of snow could mean an R-40 insulation
  • Very cold climate has different ice dam causes (siding warms, heat affects roof edge melt)
  • Venting a roof with vapor diffusion when using SIPS (insulation paneling)
  • Problem with roof leakage in January and July and not when it’s raining due to HVAC pulling in air and blowing out air at wrong direction each of those months
  • Isolated material VERSUS assembly
  • Humidity affects airplane take off speed, need more speed and lighter weight
  • Vapor diffusion port at ridge to deal with hydro buoyancy (works up to climate zone 3) with no combustion appliances and you can bury ductwork in the insulation
  • Radiant barrier at attic ceiling in mixed humid climate vented attic = crazy
  • Code won’t allow return ducts in closets even when humid closets may need this to resolve mold issues (widen door gap for greater ventilation)
  • Return in utility room for condensation on the HVAC unit and make up air from hallway
  • Concrete foundation control joints … because if you don’t create control joints the concrete will create them for you (cracks).
  • Control joints = more is better for exterior concrete
  • Interior insulation at foundation = superior
  • Thatched roof idea to manage water
  • Rigid insulation or spray foam (2 lb density) ON foundation, and crawlspace underside
  • CRAWLSPACES: should be COMPLETELY OUTSIDE or COMPLETELY INSIDE
  • Paint or cover new slabs exiting moisture during building.
  • MASTIC COATED ALUMINUM over foundation to prevent termite infestation
  • Heat loss is radial
  • Damp proofing stopping at grade for residential basements
  • Mass timber protection during construction = biggest challenge
  • Trash chutes should have negative pressure 🙂

Day 3

  • OSB: the Spam of wood
  • Rainscreen = rain coat for your house
  • Stucco with asphalt impregnated paper behind it: felt fibers would absorb moisture and then shrink and create a drainage gap accidentally.
  • Problem isn’t stucco it’s the lack of a drainage gap
  • Northern OSB Aspen, Southern OSB southern yellow pine (less dimensionally stable)
  • Plywood requires a greater skill set to produce (2 plywood producers left in America).
  • The 7% to 9% volume increase of water from a liquid to solid
  • PPPPP: problem, people, pollutant, path, push/pressure
  • Accurate air testing approach is to ask if a specific pollutant is in the air and to test for that, then repeat the process with path and pollutant pressure combination
  • Hand = 5 Pascals, Licked Hand = 1 Pascal
  • Test & Balance reports don’t measure pressure
  • Drop ceiling panels when exposed to water give off buteric acid, which smells like vomit after 1 day, but staining is not always visible. Return air plenums located above the ceiling panels can pull in the odors.
  • Gas fire place pilot lights generate soot
  • HVAC distribution systems should help compensate for leaky, old buildings by being tightly sealed, having returns at each floor, etc.
  • Dilution is not the solution to indoor air pollution
  • ERV maintains the temperature/HVAC
  • Fireplace make up air from 1-3 partially opened windows and a carbon monoxide detector.

Day 4

  • Less than 20 inches of rain annually = “low(er) risk”
  • 3 different qualities of brick (historically) used differently at 4 sides of a house.
  • “Weather side” of the house should have the highest quality wall
  • Brick has different saturation points and irreversible expansion from freeze-thaw happens beyond that saturation point. Discovering that saturation point requires test each individual brick, which require $500-$600 to test each brick.
  • Brick Porosity determines capillarity
  • Historically we used to focus on where the worst damage from weather would occur (corners)
  • Stucco was originally used to patch older buildings
  • In Europe, stucco repairing/maintenance are a common staple building material
  • A quality built stone residential home these days would cost about 40-50% more than the low ball residential
  • Vapor permeable (acrylic latex) paint can actually be good for covering brick with, when maintained.
  • If you build with very good materials, you can get away with bad water management for a time.
  • Lime-based mortars sacrifice mortar for the brick. Portland cement based mortars sacrifice brick for the mortar.
  • Sub-fluorescence 1-2 mm is where the damage can happen
  • 25-30 years = re-pointing
  • Thinner drainage gaps also contribute to reducing fire
  • Capillary breaks can help prevent the need for sophisticated repair methods
  • Granite rock doesn’t suck water and can be used as a capillary layer
  • Borate/boric acid cylinders inserted into wood to help preserve the wood
  • Capillary rise at foundations below 1.5 feet from joists
  • Germans: insert hydronic tubing with a moisture sensor and when the moisture gets to a particular percentage the hydronic heating turns on to dry out the area
  • Poly modified stucco can’t breathe
  • Moisture damage solution for basement floor structure: Cut joists and installed a capillary break as a metal column or angled metal to disconnect the structure.
  • Keeping basement to at least 40-45 degrees to avoid heat coming in towards foundation
  • Painting all SIX sides of wood siding
  • 7.5kW use home = “net zero”
  • PVC fascia and trim
  • Ultra-violet keeps the coils clean, but not the air.
  • Foster 40‑20 (Fungicidal Protective Coating) for mold control

Related:
+ BuildingScience.com
+ The UnBuildIt podcast tribute to Building Science Corporation (35 min)

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