I retrofitted a sump pit into our basement, along with new weeping tile. The top of the sump pit is about 3 or 4 inches lower than the top of the floor.
I'm at the point where I need to pour new concrete, but I don't know what to use to create a barrier over the pit to prevent concrete from covering it. I imagined a cylindrical wall that sits on top of the pit's entrance so concrete can be poured around it. However I can't find such a product.
What should I do?
Try googling sump pit extensions. There are many options there.
You didn't post the diameter of your pit or I could be more specific.
There are products called form tubes, that can be purchased in different diameters and cut by the foot.
If you can find a bunch of scrap 2x6s or bigger, make a form. Nail/screw them together and cut them into a circle.
A jig or reciprocal saw should cut a decent enough curve.
Cutting up an old steel/plastic barrel of the right size should work also. If it seems weak a couple of 2x4s inside should stiffen it enough.
Do not cut into a barrel that has/had flammable stuff in it, unless knowing how.
Find any way you like to create a properly sized circle. You might be able to source a secondhand plastic barrel that's the right size, for example.
The usual way to form curved shapes is with flexible material like hardboard. 3/8" or 1/2" thick material probably won't make that tight of a circle, so use several layers of 1/8".
Rip it to 4" or whatever your slab's thickness will be, then wrap it so it fits the shape of the barrel and run some screws through the layers from the outside to lock it. Use sand bags or cross blocks or something else to hold position while you pour the concrete, and check periodically that it hasn't shifted.
I would consider excavating a channel an inch or two deep around the barrel so the concrete flows around it and locks it in place.
Make the top of the pit one brick width below the floor level and you can mortar a row of bricks on edge around it to make a polygonal hole approximating a circle (unless you buy fancy circle-making curved bricks if you can find those in the size you need.) Or prepare a bed 2 bricks plus mortar deep around the sump and use two layers of bricks in a running bond. Effectively it's a concrete form you leave in place.
This is a problem that already has a solution. Google "circular paver mold", or "plastic flex concrete mold" and you'll find dozens of products. Your local builder's supply house or masonry supplier will sell you what you need.
I would find some Sonotube and set it with around the sump drain, making sure if was deep enough down so concrete couldn't run into it from below,and no bigger of a pour than it is, I would vertically run some one by twos a foot or so apart so I could set anchor a runner across them for a little bracing. As for anchoring it down, it looks like you will be fine just setting something heavy on top of that runner and pouring it slow. I'm assuming this a Sack Crete pour and you won't have to worry about a strong enough blast from a concrete shoot to send it flying. I would dump a wheelbarrow of concrete around it and away from it and just work it up there slowly with a shovel or come a long, it with my foot. You shouldn't have a hard time taking the Sonotube off afterwards either if it isn't anchored down.
I would cut horizontal 4 inch slices out of a 5 gallon bucket and rivet two of them together to get the proper girth. Use the circular well edges as a limit on the circle. Or, build a wood box about 4 inches deep with no bottom or top. Mount it on top of your pit as a superstructure for what's to come. Now sue that framework to support 6 inch wide lengths of 1/8 thick plywood which are to be laminated together, several layers together to make a sort of cylindrical plywood wall to block the cement from getting into the well. Lots of wood glue between layers.
I would cut back concrete and pour the concrete to sump,that way if you ever have a pipe break you can watch the water run to the sump and save a flooded basement. Usually about 4 ft out from center of cover.good luck.
