Have you ever wanted to air and weather seal a building in one continuous barrier with no seams or fear of tearing the wrap membrane? It would certainly save a lot of time and energy. And saving time on a job means saving money on labor costs. A continuous air barrier also does a better job at keeping the building airtight which translates to better energy use and savings for heating and cooling, as well better longevity for the structure by protecting what is inside behind it and the walls. Even better would be if this weather and air barrier solution was easily applied in a variety of conditions, and was a sustainable product with minimal impact to the environment and low VOC.

At Small Planet Supply we have just the product to meet all of those needs! We have carried Prosoco Cat 5 for several years now, and it has always been a favorite of those that have worked with it. If you’re unfamiliar with the product, here is what you need to know about Prosoco Cat 5: It is a single component, silyl-terminated polymer (STP) that is applied with a roller or sprayer (this is a NEW feature!) to produce a highly durable, seamless, elastomeric weatherproofing membrane on exterior sheathing and pre-cast concrete. It has proven to prevent water and air penetration into the building envelope in a variety of conditions, from everyday weather to the torrential rains and 155-mph winds of Category 5 hurricanes! Hence the name, Cat 5.

Cat 5 is designed to be the primary air barrier for structural surfaces and is meant to be used in conjunction with the rest of Prosoco’s R-Guard line of products, Joint & Seam Filler and FastFlash. After prepping your surfaces with Joint & Seam, and dressing rough openings with FastFlash, Cat 5 can be rolled or sprayed on for a solvent/isocyanate/phthalate-free air and weather barrier system. This family of products conforms to all VOC regulations while providing superior long-term adhesion, crack bridging and weathering characteristics.

Not only is Cat 5 great after it’s been installed, but actual application of the product is also a breeze thanks to the ability to either roll it on like paint or use a sprayer to apply it. Customers have been asking about spraying Cat 5 for years, and Prosoco has been hard at work refreshing the formula to make it easy to do just that! Now you can spray this as well as roll it, in a wide range of conditions. Cat 5 will bond to most common building materials without priming and will bond and cure in wet weather and on damp substrates for a seamless membrane that is capable of self-sealing around fasteners. Check out this video of a project for UCLA that used Prosoco Cat 5 for 180,000 SqFt of air barrier. https://www.youtube.com/watch?v=gd1BBU6vekg

Cat 5 comes in 5-gallon buckets capable of covering 50 SqFt per gallon on Concrete and OSB with two coats, or 80-100 SqFt per gallon on gypsum board and other non-porous materials with one coat. Small Planet Supply carries both Cat 5 and Cat 5 Rain Screen, with the original being an orange color, and the Rain Screen being a grey color for use where there is an open façade that will allow it to show through. Both of these products are available on our newly revamped webstore, and we offer FREE shipping for all Cat 5 5-gallon buckets, which is a significant savings! Be sure to check out the rest of the R-Guard line of products as well for a complete solution and remember that other tapes and membranes won’t stick to Prosoco R-Guard products!

If you’re interested in spraying Cat 5 for a weather and air barrier on your next building, Prosoco has put together a good instructional video here https://www.youtube.com/watch?v=EgvIgPOYWpo .The recommended spray equipment is listed at the bottom of this page, or you can find it on the Product Data Sheet: https://prosoco.com/Content/Documents/Product/RG_C5_PDS_071921_C.pdf. You can check out the product page for more information as well https://prosoco.com/product/cat-5/.