Our recommendations for the construction of your garage pit

Tips for designing your garage pit

To design your pit with the dual objective of providing your workshop with a safe and efficient work tool, you must comply with the regulations and design principles set out in recommendations R468 and R469 of the NIRS (National Institute for Research and Safety), while keeping in mind productivity and performance.


Here is a summary of the design recommendations to ensure that your pit complies with the regulations and our recommendations to provide you with a perfect working tool

We adapt the length of your pit to the vehicles , types of maintenance you do and of course the available space in your building. You must keep at least 1.5 m on each side of the pit to be able to circulate with handling equipment.

Integrate a 200mm metal beam UPN at the top of the pit, in anticipation of the reception of your pit protection, of a pit edge jack and/or of an oil recovery tank.

Plan for a clear paint on the walls for a better for a better r eflection of light, a non-slip floor and the use of non-combustible and waterproof materials for a total watertightness avoiding any risk of soil pollution but also a resistance to chemical products. A watertight pit will save you from any water rising, will be easy to maintain and washable with plenty of water, and will ensure you a safe work and a strict respect of the environment ( foresee a retention tank at the bottom of the pit

How deep should your pit be?

Adapt the depth of your garage pit for a perfect working height

> 1.40m minimum for heavy vehicles maintenance

> 1.60m for light vehicles, utility vehicles and buses

For optimal comfort and to reach the chassis more easily for certain operations, you can add a platform at the bottom of the pit to gain a few precious centimetres.

What width to facilitate vehicle access?

0,90 m for the maintenance of light vehicles, utilities, general order for all vehicles of less than 3,5T.

1,10 m for trucks, agricultural machines and construction machines.

1,20 m for bus pits

If, as for the municipal technical centres and workshops, you have to maintain a very varied fleet of vehicles (from cars to maintenance vehicles), you can also consider designing a pit with 2 different widths and 2 different depths.

Identify two accesses to the pit

For a pit longer than 10 m, you must have two accesses with "full width" stairs equipped with non-slip and non-combustible steps. For a pit of less than 10 m, a fixed pit ladder , clearly designated as an emergency exit, may be tolerated and will allow you to optimize your pit work space.

The importance of good lighting

Your garage pit must have a homogeneous lighting, sufficient (450 lux minimum) for a perfect visibility in your working area. Your lighting must illuminate both your pit floor and the chassis of your vehicles.

Integrate your lighting into a corbelling so that it does not protrude. This will avoid any risk of injury and will guarantee a better life span of your equipment (provide ATEX equipment if necessary).

Compressed air in the pit

It is recommended to use non-electric tools to avoid any risk of fire and explosion. Therefore, plan to supply your pit with compressed air , with valves and quick connectors to connect your pneumatic tools simply and quickly. As with lighting, it's best to build your compressed air system into a corbelling . You can also equip your pit with an air reel, if necessary, which should preferably be stored in a niche.

Integrate a storage niche

In order to keep the work area free and uncluttered and thus avoid the risk of injuries and falls, we recommend that you install storage niches to store your equipment , gearbox and deck oil reels, grease, air and all your workshop equipment (used oil collector, servants, vacuum cleaner etc.).

We advise you to have a maximum of storage space for your workshop equipment.

Management of new and used oils

Provide for an ergonomic arrival of new oils (gearbox oil, axle oil and grease) via reels that will be fixed in your niche.

For oil changes, equip your pit with a used oil collector (at the bottom or the edge of the pit) and provide a pneumatic pump to drain effortlessly to an aerial used oil storage tank , preferably to avoid any risk of soil pollution.

Secure your pit with a suitable closing device

Protect your pit with a flexible or rigid cover that should be easy to use, eliminating any handling constraints and efforts: the ideal is to integrate a motorized pit cover into your U-shaped pit edge angle, which complies with the Machine Directive and is CE certified.

Avoid the use of gratings, chains, bodyguards and any other mobile equipment on or around the pit, which requires tedious daily handling.

An unsuitable pit closure system that is difficult to set up will not be used or will be used too little and will therefore cause insecurity, MSD (musculoskeletal disorders) and work accidents.

Choose a motorized rigid cover system or a flexible curtain that is very easy to set up

Ventilate the bottom of the pit and extract the exhaust gases

Your pit should be equipped with a suction device for polluted air at the bottom of the pit , which will extract 15 to 20 times the volume of air per hour. The aim is to circulate and renew the air in the pit to avoid intoxication from the heavy gases that descend and stagnate at the bottom of the pit. An open pit, even in a ventilated workshop with open sectional doors, is not sufficient to renew the air.

Provide an adapted exhaust gas collection system to suck up and evacuate these gases to the outside.

Think about your pit lifting solution

For the good design of your pit, think about whether you are going to choose a pit edge jack that will slide into your pit head angle (preferably a 200 mm UPN) or rather a pit bottom jack. In this second case, you can install a rail at the bottom of the pit and build a staircase with a retractable step that will allow you to store your jack at the back of the staircase (an example in the picture below) 
cric fond de fosse

Connecting your pit 

Plan to connect your pit with compressed air, electricity (for lighting) and strong>oil supply and exhaust .Route your ducts. It will then be much easier to connect any new workshop equipment.

Whether you are the end user, the architect, the project manager or the construction company that "owes" a pit to its client, to respect all these design recommendations and keep your budget, it is obvious that designing a masonry garage pit to standards can quickly become a real headache.

Apart from the final result, the risk of a badly designed pit can disrupt your schedule, delaying the opening of your garage and thus having heavy financial consequences..

The "prefabricated steel pit" solution then makes sense! Discover our solutions