exterior insulation is one of the single best things that you can invest in if you're building in a cold climate apart from the benefits of thermal comfort and Energy Efficiency rigid exterior insulation significantly improves the durability of our Walls by preventing condensation that can lead to mold and rot problems keeping our framing closer to Interior conditions in this video we're talking about how to integrate exterior rigid insulation with rock wall let's get into it all right so we're going to walk through this wall assembly here we have a wall that's been insulated on the exterior with two layers of a rigid rock wool product called Comfort board and this exterior insulation provides a complete thermal break between the frame structure and the exterior environment keeping the sheathing and the studs at a very stable temperature it prevents condensation on the backs side of the sheathing and it's the most energy efficient and durable way that we can build our walls now it's important to note that this rigid insulation is installed over the weather resistive barrier Not underneath here we're calling out a self-adhered weather resistive barrier and this not only serves as a really robust water control layer but also serves as a highly effective air control layer as well because that weather barrier is bonded to the exterior sheathing which means that air can't flow underneath and between the weather barrier and the sheathing unlike a house wrap which will allow air and water to travel freely between the sheathing if it happens to get behind there which it usually does so having this combination of a self adhered or fluid applied weather resistant barrier and this rigid insulation installed outboard provides a really durable and energy efficient wall assembly that will last quite a long time since it's keeping the structure and those moisture sensitive components closer to Interior conditions throughout the service life of the building could we use EPS foam or polyisocyanurate instead of rock wool absolutely but we have to make sure that we're providing a small drainage gap between the weather resistive barrier and the rigid installation rockol Comfort board has a textured surface and so water is able to drain behind it quite easily but EPS foam and other rigid insulation products that are foam based tend to be smooth and uniform and water can get trapped behind there and held in tension so we want to either use a textured drainable self-adhered weather resistive barrier like hydrogap SA or tipar drainable peeling stick a grooved rigid insulation product or we want to install a thin drainage mesh behind there we really don't need that much space for drainage to occur a 16th of an inch works pretty well an eighth inch works even better we really don't want to go higher than an eighth of an inch Gap here because we start to get an energy penalty and we start to lose some effective thermal resistance now these rigid insulation layers are fastened to the wall assembly with insulation screws or nails with these polypropylene plastic washers and these washers are designed to reduce compression on the rigid Insulation at the location of the Fasteners and it helped to actually keep them in place since the washer is keeping the head of the screw from passing through the rigid insulation board then we install vertical 1x4 furring strips over the rigid insulation layers with a 1 and 1/4 in minimum embedment into the studs 1 and 1/2 in is even better and that will secure the furring strips to the wall so we can actually attach our horizont Al cladding so we're fastening the rigid insulation to the sheathing we're fastening the furring strips to the studs through the rigid insulation the cladding is fastened to the furring strips and the furring strips transfer the loads of the cladding to the structure so that's how the system works we can also use a vertical cladding but we need an additional layer of horizontal furing strips in order to fasten the vertical boards and to ensure that we've maintained a ventilated drainage space for our sheathing we're calling out a 5/8 of an inch CDX plywood sheathing but we could just as well use OSB instead we could use gypsum sheathing if we wanted even greater fire resistance in the assembly and then we're filling the rest of the stud cavities with rock Wolf's R23 Comfort bat which will fit into a 5 1/2 in stug cavity so this places the total r value of the wall assembly at around R39 which is more or less an r2.5 effective r value so what do I mean by effective R value well every time we run into a wood stud or a framing component that's a potential thermal Bridge wood has a thermal resistance of R1 per in making it more conductive than the insulation in the cavity so at all the studs the actual r value of the wall assembly is r2.5 not R39 since it's solid wood at those locations not insulation given it's not that much since this is only at stud and framing locations but it reduces the overall efficiency of the wall assembly so it's not a true R39 wall but either way this continuous rigid insulation makes a huge difference in terms of thermal performance by providing a thermal breake if you have an R16 thermal breake on the exterior of your wall assembly you're doing pretty well so we're filling the stug cavities with our rock wool bats this also provides some additional fire protection to the assembly since fire can't travel up within this space as rock wool is non-combustible and is an approved fire blocking material and then we can install our standard gypson board over that for our interior finish material now there are some details that we need to talk about at the base of the wall we want to flash the connection at the stem wall to the framing and weather resistive barrier with a fluid applied flashing or a compatible flashing tapee to prevent air leakage and bugs as well as water from getting inside and so a fluid applied flashing like an stpe product is going to be able to bridge that transition quite well since it can adhere to concrete we also want to install a metal base flashing or Z flashing with a drip edge to kick any water away from the wall that happens to drip behind the rigid insulation and we want to tape that or Flash that to the weather resistive barrier so that water doesn't drain behind the metal flashing we want that water to be directed over the metal flashing and so we want to use either a pressure sensitive adhesive tape or a fluid applied flashing at this location to bridge that connection properly we also want to wrap a bug screen mesh underneath the rigid insulation layers and up and over the vertical wood furring strips to prevent bugs from getting in here now rockwool is quite resistant to bugs burrowing into the insulation since rock wool tends to shred their exoskeletons however we still don't want bugs getting into the space or behind the space and potentially causing problems if we're using rigid foam on the exterior instead of rock wall we absolutely must have this bug screen here because ants and termites love to burrow into foam especially wet foam they make a home out of it and you eventually end up with an ant or termite problem since they'll eventually make their way inside we don't want that we want to make sure that our rigid installation stays nice and durable for the lifespan of the structure so installing this bug screen actually is a really big deal again we want this bug screen to be a mesh-like material so that water can still drain out behind the cladding and to ensure continuous air flow we staple the bug screen mesh to the furring strips and to the exterior wall and then we're set we also want to install the rigid insulation layers in orientation with staggered and offset joints to improve the thermal resistance at the seams of each rigid insulation board this ensures that the framing is adequately insulated and it will prevent colder temperatures from reaching the sheathing at those gaps now the amount of rigid insulation that you need on the outside of your wall assembly is dependent on your climate zone the type of rigid insulation that you're specifying and the performance goals of your home I see rigid insulation primarily as a tool to prevent condensation on the backside of the sheathing and a means to improve durability a bonus to this is is that it significantly improves the thermal performance of the wall assembly and improves the Energy Efficiency of the home however the warmer the climate that you're building in the less rigid insulation that you'll necessarily need to prevent condensation it's not to say that you wouldn't want rigid insulation on the outside of your walls to improve the efficiency of the air conditioning systems and to prevent heat gain but you don't actually need it to prevent condensation in colder climates you absolutely need rigid insulation to prevent condensation or a smart Vapor retarder membrane or some type of vapor throttle in the assembly to slow the movement of vapor so that it doesn't condense on the back side of the sheathing we want our wall assemblies to be moisture safe and durable and installing rigid insulation outboard is one of the best things that you can invest in after a rain screen if you're looking for high performance wall details like these pick up my cad details for my energy efficient high performance wall assemblies these details include the wall assembly shown here as well as comprehensive window assembly information that illustrates how to incorporate rigid Insulation at the sill jams and window heads at six different wall types including assemblies with rock wool wood fiber zi R insulated sheathing EPS Foam and More the details are only available at aeri Dash designs.com shop links will be in the description below for now good luck with your projects [Music] cheers