CORNELL CORPORATION 
Vent-Top ThermaCalX® PRODUCT PRESENTATION 
The standard vent space is 1" deep, and 1-1/2” or 2” depth is available as an option. The layout of the small wood spacers leaves over 92% of the area open for air movement. This allows air flow in all directions to give improved cooling and ventilation throughout the roof area, especially at hips and valleys. Spacers are less than 12” apart to minimize deflection of the sheathing. Foam sides and ends are available with tongue and groove profile to reduce heat loss at the joints. Please see the attached Data Table for available sizes and performance data. USES, APPLICATIONS Vent-Top ThermaCalX insulation is used when you want to insulate outside the structural roof deck. This occurs in many buildings with cathedral ceilings or where the attic is climate controlled to protect sprinklers and mechanical equipment. The roof deck may be steel, wood or concrete etc. Vent-Top ThermaCal X1 and X2 provide excellent insulation values combined with a ventilated area below the roof sheathing. 
This photograph shows the tongue and groove foam edges on four sides of our vented roof insulation. This is available when specified and will reduce the heat loss at the joints. The wood edges are cut back or rabbetted to allow for proper clearance at the panel edges. Re-Roofing – The application of asphalt shingles directly to insulated sheathing has contributed to many premature roof failures. Ventilated roof insulation is a solution to the ventilation problem when re-roofing buildings with cathedral ceilings. ADVANTAGES SHINGLE WARRANTIES - shingle manufacturers and the Asphalt Roofing Manufacturers Association require ventilation between the roof sheathing and any insulation. The lack of proper ventilation may void the shingle manufacturers warranty. See A.R.M.A. Tech. Bulletin 211-RR-94 (Copies available from Cornell Corp.). Ventilated Surface - Vent-Top ThermaCalX provides the ventilated top surface that many contractors and shingle manufacturers require. In hot weather this cools the sheathing and shingles. It also allows any moisture to escape. In severe winter weather it provides a cold air space below the top sheathing. This cold roof reduces snow melting and the possibility of run off forming ice dams and causing leakage above the walls. Ventilated Space - The air space provides over 10 sq. in. of Net Free Area per lineal foot of Insulation after deducting for the spacer blocks. This gives 20 sq. in. of Net Free Area per lineal foot of ridge (insulation on both sides) and exceeds the standard 18 sq. in. per foot used in the ridge vent industry. The spacers are solid wood to resist compression and occupy only 8% of the panel area. They leave 50% open for lateral (across the slope) ventilation. This allows maximum air flow both up the slope and horizontally. UNDERWRITERS LABORATORIES CODES AND COMPLIANCES CODE ACCEPTABILITY CERTIFICATION Plastic foam must be protected from flame on the inside by a suitable barrier. Some codes required a 15 minute barrier. Generally, wood decking or drywall is acceptable and plywood or metal decking are allowed in certain roofing applications. CHECK LOCAL CODES. FEDERAL SPECIFICATION – foam meets HUD/FHA Use of Materials Bulletin No. UM71a, ASTM C578 and AASHTO M230. MODEL CODES - foam insulation is in compliance with: VENT SPACE PROPERTIES Depth: 1" (25 mm) PHYSICAL PROPERTIES Foam: SPECIFICATIONS TECHNICAL GENERAL OTHER PRODUCTS |