Forms for the Rainwater Tank Concrete Base
I made the forms from 1×8’s. They will be held in place with 1×2 stakes. Temporary 5 inch blocks help with spacing the inner and outer forms. More stakes are driven in and then the blocks removed.
I attached 2×4’s to these boards to screw the stakes to. I’m not a forming contractor and I’m sure there’s a simpler way to do this but, this is what works for me. I roughly position the outer forms and clamp the corners together. Then run in some screws. This worked well to create the basic box. Then I squared and levelled it as I was driving in stakes to hold it in place.
It’s funny what you discover when you film yourself working on a project. I seem to have a furniture or woodworkers approach to what is really rough carpentry. I’m not a carpenter or a builder. I simply have a passion for building things. And, I don’t have an issue at all with constructive criticism or tips from you builders out there. We can all benefit here so I welcome your feedback.
With the outside form boards in place I can make the inner walls that will create the curb. I wasn’t sure how well the forms would come apart on the inside as I was worried that they would bind against each other.
Building the Inner Walls of the Form
So I made the inner forms walls in two pieces. I cut the end off the inner form wall at a 45 degree angle on one end.
Then I reattached it with a mending board.
I figured this will make stripping the forms easier as this piece can pivot away from the corner. I’m not sure if I really needed to build them this way but it only took a few minutes to do this.
This idea came about as I was working on a square concrete planter form. It seems that it can be challenging to disassemble the inside of a closed space. More on that project in a future video.
Installing the Inner Walls
I clamp and screw the inner forms together. And attach the 5 inch spacer blocks. That worked great. It help suspend the inner form at almost level as I pounded in the stakes. I ended up using two blocks at each corner.
Once these were removed I coated the inside of the form with vegetable oil.
I bent four 10 foot lengths of rebar, wired them together and suspended them from wire so they would stay in the center of the curb during the pour.