Arreguin Design & Associates

06/07/2026

Architectural and engineering Design services for commercial and residential projects

06/06/2026

Design and construction documents Available for new commercial and residential projects

06/06/2026

06/06/2026

Custom home plans blueprints

05/02/2026

02/14/2026

66 r value in a two inch thick material! Perfect for those small places that need high insulation values like metal containers homes.

02/05/2026

Are windows like these over the sink a good idea? Let me know what you think.

02/05/2026

With Averil Packton – I just got recognized as one of their top fans! 🎉

02/05/2026

Residential roof ventilation, it's more involved these days. Have a look at the code requirements.

guided by International Residential Code (IRC) Section R806 (https://up.codes/s/roof-ventilation),

requires a "balanced" system to manage heat and moisture, typically using a 1/150 or 1/300 ratio. The standard requirement is 1 square foot of Net Free Area (NFA) of ventilation for every 150 sq. ft. of attic floor space. [1, 2, 3]
Key Requirements and Ratios

• The 1/150 Rule: 1 sq. ft. of ventilator NFA for every 150 sq. ft. of attic floor, often used when no v***r barrier is present.
• The 1/300 Exception: 1 sq. ft. of NFA for every 300 sq. ft. of attic floor, allowed if a v***r retarder is installed (Climate Zones 6, 7, 8) and/or a balanced system is used.
• Balanced System: At least 40% to 50% of the required ventilation must be in the upper portion (ridge) and the rest in the lower portion (soffit/eaves).
• Airspace Clearance: A minimum of 1 inch of clear space must be maintained between the attic insulation and the roof sheathing. [1, 2, 4, 5, 6]

Common Ventilation Types

• Intake (Lower): Soffit or eave vents are essential for drawing in cool air.
• Exhaust (Upper): Ridge vents, static (box) vents, or ridge vent systems placed within 3 feet of the roof's peak.
• Calculation: Total attic square footage $\div$ 150 (or 300) = Total required NFA in sq. ft.. [2, 3, 7, 8, 9]

Important Notes

• Roof Pitch: Roofs with pitches of $7:12$ to $10:12$ require a 20% increase in ventilation, and $11:12$ or higher require a 30% increase.
• Climate & Structure: Proper, balanced ventilation reduces ice dams in winter and prevents high temperatures from cooking roofing materials in summer.
• Obstructions: Blocking and bridging must not impede the free flow of air.

01/24/2026

With Jeri Ryan Official – I'm on a streak! I've been a top fan for 12 months in a row. 🎉