Owens Corning FOAMULAR 250 Extruded Polystyrene (XPS) Insulation is a closed-cell, moisture-resistant rigid foam board well suited to meet the needs for a wide variety of building applications. FOAMULAR 250 XPS insulation board is great for many residential and commercial construction applications such as wall furring, perimeter/foundation, cavity wall, pre-cast concrete, under a slab, crawl spaces, sheathing, and other applications.

Thickness	Sq Ft Per Board	R-Value
3/4"	32 Sq Ft	R4
1"	32 Sq Ft	R5
1.5"	32 Sq Ft	R7.5
2"	32 Sq Ft	R10
2.5"	32 Sq Ft	R12.5
3"	32 Sq Ft	R15
4"	32 Sq Ft	R20

Features
• Excellent long-term stable insulating performance at R-5 per inch
• Exceptional moisture resistance, long-term durability
• Lightweight, durable rigid foam panels are easy to handle and install
• Easy to saw, cut or score

Applications
• Slows the transmission of water vapor and moisture in masonry walls
• Provides continuous insulation over wood or steel stud framing, in insulated concrete sandwich panel walls, in masonry unit cavity walls, or when used with non-penetrating, surface mounted furring systems over masonry or concrete walls
• Insulates and retains its properties in below-grade perimeter and foundation applications, or directly beneath the concrete slab to complement the insulating sheathing envelope around the building framing
• FOAMULAR 250 XPS insulation is great for below-grade applications. FOAMULAR XPS insulation is resistant to degradation from the components of common soils
and will retain its insulating performance characteristics even after prolonged exposure to moisture
• Extruded Polystyrene Provides a weather-resistant barrier (when joints are sealed) to enhance the building’s resistance to air and moisture penetration

Product Data Table

Property	Test Method2	Value
Thermal Resistance3, R-Value (180 days) minimum, hr·ft2·°F/Btu (RSI, °C·m2/W) @ 75°F (24°C) mean temperature	ASTM C518
¾" Thickness		4.0 (0.70)
1" Thickness		5.0 (0.88)
1½" Thickness		7.5 (1.32)
2" Thickness		10 (1.76)
2½" Thickness		12.5 (2.20)
3" Thickness		15 (2.64)
4" Thickness		20 (3.52)
@ 40°F (4.4°C) mean temperature
¾" Thickness		4.3 (0.76)
1" Thickness		5.4 (0.95)
1½" Thickness		8.1 (1.43)
2" Thickness		10.8 (1.90)
2½" Thickness		13.5 (2.38)
3" Thickness		16.2 (2.85)
4" Thickness		21.6 (3.80)
Long Term Thermal Resistance, LTTR-Value3, minimum hr·ft2·°F/Btu (RSI, °C·2/W) @ 75°F (24°C) mean temperature	CAN/ULC S770-03
¾" Thickness		N/A
1" Thickness		5.0 (0.88)
1½" Thickness		7.8 (1.37)
2" Thickness		10.6 (1.87)
2½" Thickness		13.4 (2.36)
3" Thickness		16.2 (2.85)
4" Thickness		22.0 (3.87)
Compressive Strength, minimum psi (kPa)	ASTM D1621	25 (172)
Flexural Strength, minimum psi (kPa)	ASTM C203	75 (517)
Water Absorption, maximum % by volume	ASTM C272	0.10
Water Vapor Permeance, maximum perm (ng/Pa·s·m2)	ASTM E96	1.5 (86)
Dimensional Stability, maximum % linear change	ASTM D2126	2.0
Flame Spread	ASTM E84	5
Smoke Developed	ASTM E84	45-175
Oxygen Index, minimum % by volume	ASTM D2863	24
Service Temperature, maximum °F (°C)		165 (74)
Linear Coefficient of Thermal Expansion, in/in/°F (m/m°C)	ASTM E228	3.5 x 10-5 (6.3 x 10-5)

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Owens Corning Unfaced R38

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