in our last episode i stressed the importance of spending time making sure everything was carefully laid out, and we even used math to check our work. if you have done all that correctly, you shouldn’t have to think all that hard for the next part; driving the rest of the ground posts.
while there is less thinking, it’s important to still take yr time and make everything square and level. it is about finesse more than brute force (though you do need some brute force from time to time). for this operation you are gonna need the following
1. post driver 2. post level 3. pounder 4. ear protection 5. marker 6. spacing jig 7. four foot or longer level (recommended but not required)
if you are not sure of what any of these is, see the last post for more info, with the exception of the spacing jig, which will be explained soon.
ground posts for hoop houses are almost always placed four feet apart. i’m told that in warmer climates where they don’t get nearly as much snow that they can be placed five feet apart. you can measure them, but you often find the post drifting about as you drive it, and it helps to make a spacing jig. this is simply a 2×4 that has square cuts in it four feet apart that are the size of the pipe you are using. it is especially helpful if you are trying to drive posts by yrself. ideally it would have three cuts in it to help make sure you are staying in a straight line – as you may recall from geometry class, three points make a straight line, but i didn’t have that long of a 2×4.
mark all the posts to correspond to yr level line – in my case i made marks two feet from the top of my posts.
using the measuring jig place one of your corner posts in a notch and use it to measure where the next post will be positioned.
slide post level over the post, put the pounder on and slide the post driver over it. put it in the notch of the jig that is empty and then work to get it so it is close to the level line as possible without pushing it out, and is square in both directions. put your ear protection on, and drive it a couple of times. check to make sure it is square in both directions again and close to the line and keep driving until you reach the line you marked on your post. if you are using the four foot plus level it’s great to rest it between your post that is at the proper level and the post you have just driven to make sure they are driven to the same level. this is more of an issue when you are building a long house than it is when you are building a short house like ours, as the line level can sag over a long length and give you a bad read.
life is not always so beautiful as you want it to be, and when driving ground posts you often come across problems such as rocks and foundation. it’s pretty well impossible to drive though these materials so they must be tackled. two basic methods can be be employed, removal and post cutting.
of these two post cutting is the easier. if you hit an obstacle and you have over two feet of post in the ground but have yet to reach your level mark you can simply cut off the excess. use a hacksaw, cut off wheel on a angle grinder, or a pipe cutter. i prefer the pipe cutter as it’s slow but often provides the best cut.
in many situations you hit obstacles before you have driven two feet worth of post in the ground. you have little choice but to remove that which is in your way. commonly this required digging with a shovel what is in the way. you can find some pretty large items if they are large enough you might have to use a sledgehammer or jack hammer to break them apart. i’ve even heard of folks boring though foundation in order to put in ground posts.
hopefully you won’t hit anything – i repeated the process of driving posts with only a couple of incidents, having to cut two pipes, and digging out a huge piece of concrete on the very last post i drove.
in our next episode we install bottom boards.