the structural framework of today's buildings can be comprised of many different types of materials and as you can probably imagine each one of those materials comes along with it its own unique assembly process so being able to understand those two elements of a structural building system are critical in evaluating a project and determining what is the most appropriate material and Method application for that given project with this in mind we're going to take a look at platform Framing and some of the characteristics of this type of assembly process so platform framing is uh the most popular method of light frame construction primarily used in the residential construction industry but not completely so what we should really understand right from the beginning platform framing operates off of a very simple building block concept one block stacked on top of the other supporting the blocks above it so you can imagine how this type of system makes uh the method rather adaptable to different different building types particularly multi-level and single story structures so if we pull the skin away from these so-called building blocks what do we find under that well what we see is that each one of those building blocks has a set of support walls and and a base to help support those walls so very basic in nature but let's dive into that even more and look at what that actually looks like and how it comes together so let's start with the base or the platform and if you didn't pick that up yes that's where the name platform framing comes from because of this simple platform idea building one on top of the other so the platform is going to start with what's called a rim joist that you see here and that creates the exterior envelope of the platform now within that is going to be the support system for the surface the support system is going to be comprised of two two basic members the gerder beam which you see here and then in intermediate joist that are going to be supported by the girder beam and also the perimeter foundation wall which was already in when we started once that is all in place that provides the support structure to put the surface on which is going to be our decking and the decking is going to be made up of 4T by 8T sheets of plywood typically ranging anywhere from a half inch to 3/4 of an inch in thickness and the thickness of that plywood is going to vary depending on the spacing on your floor Joys uh and your spacing would typically be 16 in or 24 in on Center so once we have our platform in place place now the framing contractor has a good surface to work from to start building those support walls that we talked about those support walls are going to be comprised of three basic elements a bottom plate and a top plate which you see here and those are going to create the horizontal extents of the wall system within the confines of the bottom plate and the top plate are going to go What's called the studs that you see here and the studs are going to be fastened to the bottom plate and top plate typically using Nails the studs will create the vertical support and also the vertical limits of the the Wall height now those these walls are going to be loadbearing so as you can imagine when you start to put a load on the top of those walls they are the the studs are going to want to uh react to that load so horizontal bridging is put in between the stud spaces to create uh a better uh load support for the um for the wall system so once the wall is all framed up then it will be lifted into place and temporarily supported until the rest of the framework can be put in place now when they put the wall in place they are going to have to Plum it to make sure that it's perfectly it's standing perfectly vertical they put their support uh their temporary supports in place and then begin building the rest of the walls now what you're going to notice here is is that the wall they did not build the entire wall all in one piece we have two different elements here the reason for that is because as you can imagine the larger section of wall you build the heavier it gets consequently making it harder to manage when putting it in place so they build it in segments making it easier more manageable uh in the installation and the way those wall segments are tied together is with a second top plate which you see here that overlaps one wall from the other and gets tied together so now you've got multiple wall segments within one run of wall that are built separately put together and then tied together with a top plate and that process is going to be continuous all the way around the building perimeter and then also on the interior of the the building Envelope as well and that is the basic setup for giving you your box that your your building block that we talked about earlier you've got your base or your platform and then your support walls on top of that platform and if you have a multistory structure then the process is repeated for the second level until you get up to the roof level where the roof is framed up and that will be talked about in a um in a later video now the walls can either be sheathed after they're all permanently in place or while you're framing them on the platform there's advantages and disadvantages to both and I'll leave that for you to think about on your own e