Well, there are a few more of you checking out the blog this morning….that is good news for you as I believe there is lots of good info for you there.
Let’s call this an extra post for the module! We looked at calculating the way to cut studs on a “rake” wall – that is a gable end of a building. We did this when we were figuring out how to cut the studs on the parapet walls of the sheds. This is a common problem for us carpenters. If you look around, there are dozens and dozens of gables walls out there, all built by carpenters!
The formula is on the whiteboard:
I know it is hard to read, so I will clarify.
What we are trying to figure out is the difference in length between one stud and the next one. The formula is: diff = O.C. measure divided by the run multiplied by the rise:
O.C. / run x rise
Seeing as the slope of a roof is always expressed in the run being 12″, and the rise is found in the slope triangle of the plans or can be discovered using your speed square as I showed you, it is fairly easy to do the math.
In the case of a wall with common “on centre” spacings, the the calculated difference will be applied to each subsequent stud. If the O.C. spacing is 16″, for example, and the slope is 7/12, the the formula would be:
diff = 16/12 x 7 = 9.33 inches or 9-5/16″. That means each stud will be that measure longer (or shorter) than the one beside it.
Phew….confusing? Let’s go over it in class if you need to.