I have a fire pit in my backyard that I dug. After a large rainfall, it fills with water. Some of my friends have suggested lining the sides with clay so it bricks itself in. Will this prevent water from seeping in through the sides? Also, what is the best way to build a cover for it?
Cover the bottom with lava rock, that way you’ll have drainage. This guy demonstrates how to put in a cover.
If it’s filling to the top with water you might have a tough time. The clay might work, if not I think you’ll need to line it with reinforced concrete. Not all that tough to do. You need wire mesh reinforcement because of the heat and cooling cycles. The concrete mix will suggest the minimal wall depth, at least 2 inches. For an effective lid you need the pit to rise above ground level for several inches, and then you can use anything that will cover the opening and allow water to drain off. I’d dig down a few inches around the perimeter and fill with gravel for drainage away. You might want to go out a ways from the perimeter with gravel to carry surface water away, maybe even a drainage channel with gravel to carry the water downhill.
You could line it, like the others mentioned, that was my first thought as well. Dig it another foot deep, dump in some rocks, then build fires on that. But I think the easiest thing to do is just get a piece of wood to throw over the top when you’re not using it. If you don’t entertain often, just drop a square piece of plywood over the top and leave it there. When guests come over, hide it somewhere out of the way. Every couple of years when it’s warped and falling apart, replace it. If you entertain more often, cut it so if fits the shape of the pit and paint it so it looks nice (also, don’t use plywood), then you can leave it on when you don’t have a fire and it can even double as a table. This also give you the ability to keep firewood in the firepit ready to go without it getting soaked all the time.
You dug a hole in the ground, and it fills with water when it rains. This is surprising?
Moderator Note
He didn’t say it was surprising. This answer is both useless and jerkish. If you can’t give a helpful answer, there’s no need to reply. No warning issued, but let’s refrain from snark for the sake of snark in GQ.
Colibri
General Questions Moderator
This Old House recommends a base of 3/4 crushed stone for drainage. It’s put in and tamped down in several steps.
Directions in article.
When we put our pit in we have a small drop off to the side so water running in wasn’t a problem. I just sloped a slight grade around the pit. To handle the water filling in, I dug a drywell. I went as deep as I could get with a post hole digger, 8" diameter about 4’ down the center of the pit. I filled that with gravel and sand. Our soil is heavy clay. On top of that is an old carpet to keep the next 4-6 inches of sand from falling in. This is the base of the pit. My pit is about 6" poured cement that ends at ground level with a 6" cement lip around to keep the grass from growing and burning too close. The lid is a very large trash can lid that happens to be close to the correct size.
Get the rim above ground level.
This prevents runoff from filling it.
Line it with something (clay is easy/cheap, concrete is better.Eliminate/reduce seepage.
For a cover - go to a huge “All-In-One” store and let your mind wander - with a tape measure and the dimensions of the hole.
A garbage can lid might work, a child’'s disk sled might work - you are looking for anything waterproof, durable, and large enough to at least cover the hole.
If nothing presents itself:
Concrete backer board - 3’x5’x 1/2" board used for tile install
If you end up with wood - get real exterior-rated plywood and some scraps of 2x4 the 2x4 bits get attached to the board so as to rub against the side of the hole and prevent the sheet from sliding off.
Paint all bits before assembly and again after.