Keep your foundations solid

• Industry Type: Industrial Manufacturing, Warehousing, Refurbishment, Food Processing, Cold Storage
• Author: Andrew Newby
• Service Area: Advice
• Date: 26 Jul 2011

REVIEWING YOUR FACILITY’S FLOOR

Plant fit out usually includes installation of walls, ceilings, doors, mechanical and other services within an existing building shell.  In many cases, the building was originally built for one function (e.g. warehousing) and the fit out is necessary to convert the existing functionality to another type of operation (e.g. manufacturing). 

Two common issues arise relating to the concrete floor:

• Can the existing floor be kept when new drainage installation is required?
• Is the floor structurally adequate to support new equipment loads?

Adapting the floor to suit new drainage requirements
Options for consideration include:

• Lay a topping over the floor—this is difficult where you have to match the level of a topped/built-up floor and a flat floor.  The thickness of the topping must be sufficient to ensure the floor does not crack and break away.  A build up of epoxy is typically not viable, as thick applications are expensive.  Achieving good falls to drains is critical from a food safety compliance point of view. 
• Cut slots for drains—it may be possible to cut slots in the floor for drains. Cutting concrete and demolishing the infill section can be expensive, depending on the floor thickness and machine access.  Once the slots are cut, you still need to resolve floor slopes described in the previous point.     
• Demolish the floor—this is often the best solution, as it avoids expensive concrete cutting.  Demolition equipment can efficiently demolish the concrete, without concern for preserved sections of the floor.  This option provides total flexibility for drain types and locations. 

Common floor construction designs
Reviewing floor design is an important step when considering the most feasible option. There are a number of floor designs that may have been used:

• Conventional reinforced slab on ground – typically laid on the ground with minimal reinforcing to control shrinkage cracks.  You can usually identify this type of floor by a grid of joints present. 
• Conventional suspended floor – designed to span between supports such as columns, beams or piles.  The concrete has heavier reinforcing than a slab on ground to help it span the distances.  If there is access under the floor, it is likely to be a suspended floor, although suspended floors may also be constructed on the ground.  The floor will have fewer joints than the conventional slab on ground. 
• Post-tensioned floor – designed to tension the complete floor with high tensile cables in ducts to eliminate joints.  It is a popular construction method for warehouse floors to minimise floor joints.  It is a common misconception that post tensioned floors are always suspended.  Post tensioned floors may be constructed on the ground to reduce the concrete thickness and eliminate joints.  It can be an economical floor solution for flat floors.

Demolishing floors or even coring holes in a floor can present challenges.  If the floor is a conventional reinforced slab on ground, the exercise is relatively simple. If the floor is designed as a suspended floor or a post tensioned floor, extreme caution must be observed.  Cutting the concrete (and reinforcing) can have severe structural and safety consequences.

Structural adequacy
The structural adequacy of the floor may require review by a structural engineer. This may be warranted in the following situations:

• Installation of heavy equipment or tanks – especially where the floor is a suspended construction
• Where trucks or heavy materials handling equipment will be driving over the floor
• Installation of high pallet racking which may have heavy leg loads

Loads will need to be estimated and assessed against any information you have available on the existing floor.

Professional advice
Don’t assume that because the floor is on the ground that it is a conventional floor and change is simple.  The consequences can be catastrophic and therefore it is important to obtain professional advice from a structural engineer or construction professional when planning a fit out that affects the floors. 

Review of these items early in your project planning ensures the changes are feasible and that budgets are adequate.  If you are considering purchase of a property, the floor construction and proposed changes should be part of your due diligence.

About the author
Andrew Newby is the Business Development Director at Wiley and can be contacted on 1300 385 988 or email connect@wiley.com.au.

This article was published in Food & Drink Business Magazine.