New Construction Insulation
Envelope
Absorption
Interior
New Construction Insulation Requirements
Chicago needs cellulose insulation (not fiberglass) for all season protection to retain heat in winter and block heat in summer.
• Significant difference is sound absorption / sound control
• Heat protection from radiation (direct sunlight)
• Fire retardant / fire safety
• Pest and rodent resistant
• Mold mildew and moisture resistance
• Dense packed insulation fills gaps and voids otherwise left open with fiberglass batts/ two hour fire wall
• Prevents sagging at the top of the stud cavity
• All-borate, liquid fire retardant is infused directly into the fibers, resulting in a more effective insulator at the price of competitive blended products
Cellulose Dense Pack Insulation R3.5 Per Inch
Cellulose for sound absorption, fire safety, and comfort
Closed Cell Spray Foam Walls R-7.4 per inch
Let us help you navigate the insulation choices by meeting with one of our project managers to discuss pricing and performance variables.
Cellulose 2x6 Framing R21
This is an important factor, we are dealing with weather opposing conditions in summer vs. winter. The factors related to the changing climates in Chicago makes Cellulose Insulation an obvious choice for traditional new construction.
When building a new home, budget considerations are a factor in choosing high performace spray foam vs other materials for construction. We have seen numerous examples year after year of budget cut decisions on insulation resulting in drafts, trim seams cracked or separating, crown molding and casing separation, mildew, moisture, and more!
Tackling Air Leakage
Green Attic Insulation can insulation over the attic floor or between stud cavities of walls, but insulation cannot solve air flow. It can only prevent heat escape. Let that dominate the conversation through the remaining information.
Insulation and Air Leakage – Unintentional or Accidental Air Movement – Ask your insulator about air leakage.
Often referred to as draftiness, unintentional and accidental air movement account for a host of undesirable conditions, which can be treated and resolved. Green Attic Insulation has offered comprehensive whole house approach energy audits for many years now.
In the process our our years of case studies, we have compiled valuable information on the variables of creating a comfortable home. Some simple and affordable fixes, where the treatment plan would be similar for most homes.
This being said, we are careful not to place a percentage on energy bill reduction without achieving meaningful improvements to strengthen the air barrier. Air sealing will stop air infiltration.
What do you absolutely need to know by the time you finish reading this?
A stable, healthy, consistent, comfortable , and conditioned living space is the goal.
Treatment of the air flow, heat flow, and moisture flow through the conditioned space are the clear objectives.
It is essential to break down these three types of movement into their own conversations and separate the diagnosis and treatment of each. This is a separate but equal conversation when discussing insulation.
Starting with Air Flow
Also referred to as the “pressure barrier” of the structure, air flow ( unintentional / unwanted air flow ) through the conditioned living space is the cause of over-running the furnace in the winter and cooling system in the summer.\
Air Movement / Air Infiltration Methods
Whole house approach identifying methods of Air Exchange (per hour)
1. Wind effect
2. Stack effect
3. Combustion and Ventilation
Insulation and Wind Effect – Think the flag in the yard blowing in the wind. Ask your insulator about wind effect.
Wind / Breeze creates a positive pressure on the windward face and negative pressure on the non-windward facing walls, which pulls the air out of the building.
Wind causes infiltration on one side of a building and exfiltration on the other. Wind effects can vary by surrounding terrain, shrubs, and trees.
Maximizing Energy Efficiency
This is not achieved with more insulation between stud and drywall cavity. We find the most vulnerable point of the structure is the seam between the foundation and siding.
This can be achieved with exterior caulking or one part spray foam ( depending on the size of the gap and the aesthetics of the building material.
b. The untreated seams at the foundation level will result in cold first floors around the parameter of the home and cause substantially higher heating costs as cold air is being drawn in through breaks in the pressure barrier.
Wind defense is often overlooked due to seasonal restrictions. For example, the caulking around the window, doors, facia, and any other seams of the external structure cannot be done when the temps are below 40 Degrees per manufacturer recommendations for adhesion and proper curing.
So if a contractor meant to schedule the air sealing of the exterior and spring and never got around to returning, the homeowner ( while the home is new and beautiful) has a major air leakage problem, and resulting higher cooling and heating costs for many years to come.
c. Insulation Vs. Air Movement- Stack Effect
The “stack effect” is warmer air moving upward in a structure.
The rising warm air creates positive pressure above, neutral pressure between, and negative pressure on the lower levels.
Reduction in pressure in the base of the building, forcing cold air to infiltrate through open doors, windows, or other openings. The stack effect basically causes air infiltration on the lower portion of a building and exfiltration on the upper part.
d. Indoor Combustion and Ventilation – Indoor bath fans, dryers, range hoods, etc
Mechanical ventilation air movement varies by device, and can cause substantial pressure differences. A common bathroom fan generates between 90-110 CFM ( cubit feet per minute , a cubic foot is about a basketball of air) , while a range hood over the stove can draw as much as 1800 CFM.
These devices must be balanced with air intake or result in unwanted air flow through the building envelope.
Now having identified three types of air movement / air flow, we can separate treatment of the air leakage by targeting the same corresponding air movement paths.
For example, partitions, pathways, and intersections of the exterior to reduce wind movement. In the attic top plates and wall to wall connections are sealed to significantly reduce stack effect.
This includes recessed lighting, attic hatch or pulldown stairs. Openings around flues are flashed and fire-caulked to prevent stack effect though flu clearance framing.