how do you build a septic tank cover?

Answer 1

There are quite a few different types of septic tanks, but the most common is a buried concrete vault. The access hole in the top is usually covered by a removable concrete lid. Some are round and some are square lids. They are usually 24" in diameter or 24" on each side. They are usually 3-4" thick and are steel reinforced. The tank, lid and all is usually completely buried. I have seen the lids buried as little as 6", or as much as 36" below the surface of the ground. Lids are sometimes damaged when they are run over by a heavy vehicle. I assume that this is the type of lid you need to replace. They are not extremely difficult to make, but for the money, you might want to consider buying one.

If you know the size you need, call the nearest plumbing supply business and they should be able to hook you up. If there is no plumbing supply business in your area, call a couple of local plumbers. They will probably be able to either get you one or tell you where you can get one.

If you decide to make one, a square one will be easier to make than a round one only because it is easier to frame up the concrete form. Start with a piece of plywood that is larger than the dimensions of the lid. If it is square, form it to the appropriate width and length using 2" x 4" boards, and fasten nail them to the plywood. If you are making a circle, you might want to buy some flexible landscape edging that can be easily made into a circle. Some short 2" x 4" blocks nailed to the plywood on the outside of the cirdle will keep it in place. You might need to trim the height of the vinyl edging so it is only 3 1/2" to 4" high. Cross hatch and wire together four short pieces of 3/8" reinforcing rod. Your home center will cut it to length for you or you can use a hacksaw. Set the steel aside intil you have poured the concrete.

Before you pour the concrete, spray the plywood and sides of the form that will be in contact with the concrete with mineral oil. A quart will be more than enough and you can use a spray bottle or even an old paint brush to apply it. This oil will keep the wooden forms from sticking to the concrete when you remove them.

You will need a little more than an 80 lb. bag of concrete mix. Another 40lb. bag should give you enough. Mix it as per instructions, making sure that it isn't too soupy. Shovel it into the form and smooth the surface. Take the steel crosshatch and press it into the wet concrete without pushing it all the way to the bottom. Smooth out the top again and all you have to do is wait for it to dry. Take the forms off the next day, and presto ... you have a new lid for your septic tank. Total cost should be under $30.00, and even less if you have some scrap wood you can use for the forms.

Good luck with your project.