Bricks, Masonry, Asphalt and Concrete - Concrete cap for sump hole in basement

We had our old oil furnace burner removed and discovered a second hole to our sump underneath it. I now need to seal that hole, and am wondering if this is something I can tackle myself. It's about 1 1/2 feet in diameter.

Questions: How thick does the cap need to be? Does it need reinforcement (what kind)? How do I build a "form" to keep the concrete from going into the sump? Is it OK to use Quickrete for this?

Thanks for any advice.

Why not build a cover out of plywood? A foam gasket can be installed to seal the gap between the cover and floor. The cover can be bolted to floor.

build the form in your yard, pour it and get some help to put it in place or as twelvepole said build it with plywood or have one made using steal or alluminium.

Those are both good ideas, although I had hoped to seal it off level with the floor in order not to create a tripping hazard. It seems like there should be some fairly straigtforward method to cap this off, but perhaps not...

Thanks for the ideas.

How big is the hole? how wide and deep?how thick is the floor you have now? Its concrete?

The hole is 14 inches diameter; the concrete in this part of the basement appears to be 2 inches thick, at least that's the thickness of the lip on the hole. There's a metal sleeve lining the hole, and I'm not yet sure what's behind it. Don't know exactly how deep it is - it's the sump and has some water in it, but it seems like I shouldn't fill it in (there's a separate hole to access it).

I'm thinking I can figure some way to get some nails in place (drill a hole in whatever is below the concrete lip) so I can get a piece of plywood down there to be the base to hold the new concrete. Not sure how to make sure the new and old concrete bond together well - do I need to do anything special? I figure I'd make the cap at least 3 or 4 inches thick, but not sure if I would need any more reinforcement for it?

Thanks.

Can you fill the thing in with dirt all the way up to 4 or 5" below your floor? If so fill it in and pour concrete on top of your fill all the way to the top of the floor. To secure it I would just drive some rebar into the fill dirt to the bottom of the hole if poss. where the top of the rebar is at the floor. Then tie in some rebar cross ways where the floor is. The floor isn't going anywhwere and the rebar should hold your cap in place if its against somthing solid in the bottom of the hole.