My Notes from Building Science Fundamentals with Joe Lstiburek (4 day course)

July 22, 2021

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

My Notes from Building Science Fundamentals with Joe Lstiburek (4 day course)

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