Understand the Purpose of Backer Rod

thing let me start by talking about why I need this background oh that's a good point so so there's kind of three reasons why one might want to use baccarat right now obviously this is a pretty massive joint here right the the first reason is actually price right if you were to fill this whole thing with sealant that would be really expensive right and we've blown this up this is a big big joint it's also actually more durable and so when you think about this joint we're pretending that this joint is moving this direction right so it's trying to move here right and the sealant is flexible right it can move as the joint moves but if we film this whole thing in with sealant right it would be stuck on this third side right so we're basically allowing the sealant to move up here but down here the sealant can't move so instead of moving freely it's kind of going to do this right and that's going to cause it to potentially crack and split sealant doesn't actually stick to back and rot so you want that in there as kind of a bond breaker to make it so that you only have adhesion on two sides because when you have a teasing on two sides it can move all at once yeah that's pretty interesting because I have no idea of one thing that the sealant wouldn't stick to backer on yeah and so it's designed for that purpose and it's designed so it won't stick then apparently the last reason to use backer