By erecting a roof, I can use gravity to channel the rainwater to the tank. While spreading tarps on the ground could gather rain and would be cheaper, then I'd need a pump to get the water up into the tank. With no electricity available to operate a sump pump, the pump idea would not work for me. A concrete pad would have the same problem, plus be quite expensive. Yes, more durable, but not my best option at the moment.
Having a roof also provides me with a dry work or storage space. Wet on top, dry underneath. Plus shade, an important factor in this tropical region. Choosing the expense to build the roof was a no brainer for me. It is worth the effort and cost. Cheaper than a concrete pad and more versatile.
Looking up under the new rain roof, you can see that 2x4s, 2x6s, and 4x4s went into the construction. The upright posts are tied into cement footings. The braces help stabilize the roof and integrity of the structure. The roof itself is corrugated metal that has been screwed into place. Hurricane clips still need to be installed at this point, to help keep the roof in place in case of high winds. It hasn't been done yet because I need to run to Hilo to buy them. The local hardware store is out. But using hurricane clips is a smart idea.
Another thing that helps stabilize the construction and add more weight is a deck. The rain roof gave me a shaded, dry area that just begged for a work deck. The deck will come in very handy.
At this point, I still need to add a rain gutter and something to direct the rainwater to the tank. The tank is right there on the edge of the roof, so it won't be complicated to do the guttering. I already have used guttering in my farm boneyard that I can use.
Tasks left to do on this project:
...install hurricane clips
...finish staining the lumber
...install the rain gutter