A sandbox , as sandbox , Buddelkiste or sandbox called, is a demarcated from the surrounding area with play sand is filled. It is intended as a play area for children up to elementary school age and is primarily located on playgrounds , in green areas or in gardens . An all-round high edging, often made of plank or round wood, serves as seating and wind protection.
You can stand, sit and kneel in the sand, if you want to stay clean you can sit at the frame, the bench. In and with the sand there is a wide variety of games possible, alone with your hands or with all kinds of tools: digging, drilling, raking, carrying, pouring, building, sieving, trickling, shaping, drawing and - unpopular with bystanders - blowing. With a little water, sand can be solidified via capillary action, with a lot of water it can be liquefied. Things can be fastened by burying or spilled. Sand cakes can be "baked" quickly and easily with sand molds ; a classic big task is to build a sand castle . Walking on the sand, the rain pounding down on it, the drying due to the heat of the sun and wind weather and over time equalize all structures made of sand.
A sandpit is usually made of wooden boards and stones and set into the ground, but there are also models made of plastic, some of which are transportable. The plastic models often resemble animals in terms of shape and color and are characterized by their compact dimensions. The shape of a shell, with ribs as stiffening and a lid to protect the sand from rain, fallen leaves and cat droppings, is common. A sandpit made of wood usually offers a bench.
Sandboxes should be filled at least 40 centimeters deep with sand, the grains of which should have a diameter of up to two millimeters according to DIN 18034. Especially with older children there have been several fatal accidents in the past due to deeply dug holes and caves that collapsed. In order to avoid such accidents, a grid, water-permeable fabric sheeting or composite stones should be installed under the sand. The sand in public playgrounds should be changed at least every two years. To reduce costs, the replacement cycle can be extended up to three times by using a suitable sand cleaning machine.
The frame that holds together the beach volleyball field, which is set up on a solid surface made of sand , is also jokingly called the sandpit. This frame usually carries a band, possibly with advertising and a net over it to hold the ball back.
About 150 t of washed quartz sand with a maximum grain size of 0.1 mm are used for a beach volleyball field.