GYMNASTICS PITS, PIT CONSTRUCTION & MAINTENANCE

CHANNEL BAR PIT SYSTEMS

Constructed with boxes or sliding spotting platform systems.

PIT DESIGNS

Unique multipurpose pit designs.
Midwest Gym Supply offers pit designs for tumble tramps, trampolines, loose foam pits, and resi-pit combinations.

PIT EDGE PADDING

We sell all trampoline padding and custom padding. Available in many colors!
Call 1-800-876-3194 today for a quote.

• Selecting the Best Type of Pit
• Design Phase
• Ground Water
• Pit Drainage Systems
• Pit Construction
• Electric Circuit
• Spring Tramp Systems for Loose Foam Pits
• Foam Blocks
• Pit Edge Padding

DESIGN AND CONSTRUCTION OF GYMNASTIC TRAINING PITS

The sole purpose of this information is to provide the best information currently available in design and construction of Pit Systems.

Training pits are a very important asset for skill acquisition and enhancing a safer learning environment. Everyone involved with the use of a pit should be made aware that pits are not fail safe in preventing a serious catastrophic injury and even death. Gymnast and coaches develop a false sense of security when using pit systems. There is always risk involved when using a properly designed and maintained pit, even under the very best of conditions.

SELECTING THE BEST TYPE OF PIT

There are two basic types of pits:

1)    Solid Foam or Log Constructed  Porta-Pit/ Resi-Pit

2)    Loose Foam Training Pits

There are obvious differences in design, construction, and use. The design phase is important to determine the projected use for the event or events that the pit will be used. Safety of the athlete is the utmost concern. Pits must be of adequate size and shape for the event it is to be used. There is no minimum safety standard established to date that are specific to the design and construction of Pit System.

DESIGN PHASE

Consult an equipment specialist or person who is knowledgeable in gymnastics equipment and gym layouts. Provide this person with as much information as possible about the intended use of the pit system. Follow the recommendations of the gym design specialist, especially in the construction of the pit system.

GROUND WATER

A wet pit is a health hazard and a major problem. Every precaution needs to be made to prevent water and moisture from seeping into the pit. This includes damp or wet floor and walls that will produce odor, mold, and mildew.

The first step is to establish the wet weather water table. This information may be available from the County Agricultural Stabilization Office. If this information is not obtainable do not take chances. Assume that ground water will be a problem. Test holes in the general area where the pit will be dug, 2’ below the bottom of the pit floor. Cover the test hole to prevent surface water (rain) from running into the test hole. Check the ground water level every 10 days. 

The second step is to establish the depth of the pit. Resi-Pit/Porta-Pits require 18” to 36” in depth from gym floor to pit floor. The depth of the Resi-Pits lessens the chances of having a water/moisture problem, but does not eliminate the possibility. Deep foam or loose foam pits always require a drainage system.

PIT DRAINAGE SYSTEMS

The perimeter drain has to be lower than or below the pit floor and have a minimum of 2’ of clean stone around the drainage perforated pipe. Accumulated water needs to be drained to an area that is lower than the perimeter drainage system. This is termed as a Gravity Drain. The drainage pipe needs to have 1/4" fall per-foot the entire length of the drainage pipe. If a gravity drain is not feasible, a lift pump located outside the pit is required. Perimeter drains from multiple pits may be connected and drained to one central lift station. The drain piping should have 1/4" fall per-foot drainage to the lift station. The lift station needs to have a clean gravel or crushed stone base of 8” to 10” with the pump resting on a concrete stepping stone. A concrete manhole or 3’ diameter steel or plastic road culvert can be used as a manhole to house the lift station. Caution! Do Not install a sump pump inside the pit to pump the water that is in the pit into a drain. There are two major reasons not to do this. The first is you want to prevent water from getting into the pit. A perimeter drain that opens into a sump is an open pipe for water to get into the pit when the pump fails. Sump pumps fail for the following reasons. The most common cause is electrical outage or electrical circuit failure. The second most common cause is pieces of pit foam or debris that gets into the sump and locks up the pump. When the pump fails, the open line floods the pit. Do not look for the easy, less expensive way. Pit drainage is one of the most important aspects of pit construction.

PIT CONSTRUCTION

Vibrated poured concrete floor and walls is the best method for pit construction. The poured concrete floor and walls need to be steel reinforced with #4 Rebar on 16” centers grid to prevent a crack from opening up. Concrete blocks can be used, but can cause problems. Blocks have mortar joints that crack. The blocks are porous and allow ground water to get into the pit.

The earth needs to be excavated 18” deeper than the elevation of the finish floor. This will allow 10” of clean stone base for the 8” concrete floor. The 8” concrete floor will support the poured concrete or block walls. When the floor is poured, the #4 Rebar needs to be turned up 90 degrees to reinforce the connection of the walls. Plastic water stop 6” wide x 1/2" thick should be attached to the rebar so that is will embed in the floor and walls equally to seal the joint and prevent and water seepage.

Once the concrete floor is cured properly the walls can be formed and poured. The walls also need to be steel reinforced with #4 Rebar on a 16” grid vertically and horizontally. The concrete needs to be vibrated during the pouring process to insure density and to prevent honeycombing. After concrete walls have cured, coat with two coats of basement sealer for added moisture protection. The drain tile needs to be covered with a minimum of two feet of clean gravel or crushed stone to prevent soil from filtering into the drainage system.

ELECTRIC CIRCUIT

Electric has to be installed to the National Electric Code.

SPRING TRAMP SYSTEMS FOR LOOSE FOAM PITS

The Bungee Pit or Spring Tramp Pit system prevents the foam from packing and reduces the amount of fluffing required. A spring tramp system cost less than the foam cubes it displaces. The spring action promotes air circulation that helps keep the pit fresh. The cost of a bungee pit varies based on size and configuration. Spring tramp systems can be installed in pits that are constructed using concrete blocks. When placing an order for a spring tramp system, it is important that you specify the method of construction. Special anchors are required for concrete block walls.

FOAM BLOCKS

Polyurethane foam is an oil bi-product and expensive. Pit foam needs to be fire retardant and meet the requirements of the local building codes. The density needs to be 1.5 to 1.7 pounds density, weight per-cubic feet. The force deflection needs to be 36 to 44 ILD. When purchasing foam, specify the physical properties that fall within these specifications. Less expensive foam of lesser densities will compact and will not provide the protection needed for the athlete. Because of the compaction, more foam will be needed to fill in the pit; cheap foam is not economical when compared to using the proper material.

PIT EDGE PADDING

The top edge and side wall of the pit should be padded to prevent athlete injuries. The standard is 1’ on top and 1’ down the top edge. Polyethylene, (Trocellen), offers a good impact absorber and cushion. The most economical pit edge padding is 1 1/2" to 2” carpet bonded foam glued down to the concrete. Petroleum base contact cement will hold the carpet bonded foam securely in place. Vinyl covered pit edge padding offers the best appearance, longevity, and is easy to clean. Vinyl covered pit edge padding offers you a choice of colors. Vinyl pit edge padding can be glued in place using panel adhesive in Resi-Pits. Vinyl pit edge padding needs to be glued and screwed down in loose foam pits. Be sure and add 2” per-side to allow the space for pit edge padding.