Explaining Joint Movement and Stretch Needs

say 700 stretch right the answer to how much you need is it depends on the size of the joint right so I'm gonna give you a scenario okay let's take a 12 foot piece of vinyl siding okay you can look this up you can Google it in the course of a day that can move up to half an inch okay okay so let's say your joint that you left for the caulking in your butt joint is a quarter and a quarter inch you're asking it to effectively double right because it's got to go from a quarter all right it's going to move to a half so what if you left an eighth of an inch instead of a quarter inch now you need it to move 400 percent right right now that's just one time right when we're talking about 700 percent stretch we're saying you can move this to seven times its initial length once and that's why it's gonna break but you're asking a sealant to do that every single day thousands of times thousands and thousands and thousands of times so a little wiggle room it's not a bad thing right yeah you know we can keep this going further right so what happens if you have a joint you make it really tight and you only have a 30 second of an inch gap for your butt joint well I'm going to tell you that you can't actually get any sealant in a 30 second of an inch right like imagine trying to get sealant in there but also try that you'd be asking it to to stretch sixteen hundred percent of its initial rate right nothing can do that you wanna basically design the joint