Aluminum strips are indeed strong enough for exterior use. They are lightweight, corrosion-resistant, and have high tensile strength, making them suitable for various outdoor applications such as siding, roofing, and fencing. Their resistance to weathering and low maintenance requirements add to their popularity in exterior settings. However, the specific strength and durability can vary based on the alloy composition and thickness of the strips, so it's important to select the appropriate grade of aluminum for the intended use.