A brewery floor is, in effect, an elaborate drainage system. While a warehouse operator may only need to specify a flooring system that will tolerate washdowns and spillages, brewery operators also need to determine whether or not liquid can reach a drain before it accumulates around vessel bases, door thresholds, channels, or along pedestrian routes.
For this reason, we recommend that brewery floors are designed from the drain backwards, paying attention to three measurable factors: the distance liquid has to travel, the full availability across that distance, and the flow the drain has to accept during cleaning. Let’s look at each of these points.
A floor gradient, or fall, is usually expressed as a ratio, with 1:60 being the ideal for commercial wet rooms, breweries, and food processing areas, and 1:40 for walkways (see Approved Document H of the Building Regulations 2010). A fall of 1:60 means 1mm of drop for every 60mm of horizontal run. In percentage terms, that is:
Gradient % = 100 ÷ ratio
So:
1:60 = 1.67%
1:80 = 1.25%
1:100 = 1.0%
The fall required is calculated as:
Fall in mm = run in mm ÷ gradient ratio
If your washdown route runs 3m from a vessel to a gully, a 1:60 fall needs:
3,000mm ÷ 60 = 50mm fall
At 4m, the same 1:60 fall needs:
4,000mm ÷ 60 = 66.7mm fall
That number should be checked before your flooring system is selected. If the existing slab, doorway levels or equipment bases only allow 40mm of drop, then a 1:60 fall can only work over:
40mm × 60 = 2,400mm, or 2.4m
This is why drainage and gully placements are so important for brewery flooring specifications. If the drain is too far from the wet process area, the finish is forced to compensate for standing water and heavier cleaning.
The drain also has to accept the water being sent to it. The basic calculation is:
Design flow = active washdown sources + process discharge + allowance for simultaneous use
For example, if two washdown hoses are measured on site at 30 litres/minute each, the combined flow is:
60 litres/minute ÷ 60 = 1.0 litre/second
Adding a 25% design allowance gives you:
1.0 × 1.25 = 1.25 litres/second
This figure should be checked against your gully, channel, trap and downstream pipework, not only the visible floor drain. Approved Document H requires that a drain carrying trade effluent should have an internal diameter of at least 100mm, which is where brewery floor layouts often expose weak assumptions. A drain may connect to pipework with adequate theoretical capacity, while the gully edge, grating slot or channel outlet becomes the limiting point. The survey should therefore record the measured washdown flow, number of simultaneous hoses, drain type, outlet diameter, channel length, trap condition and any solids or yeast load that could reduce clear flow during cleaning.
Drainage affects slip resistance because it affects how long contamination remains on the surface. Wet or contaminated floors are a major slip factor in food and drink manufacturing, with most slips occurring when floors are wet with water or contaminated with food product. The HSE therefore stipulates standard roughness levels (given in Rtm - R = roughness profile, t = total peak-to-valley height, as in Rt, m = mean value) for flooring systems in these environments: floors likely to become water contaminated should have at least 20 microns Rtm, increasing to 45 microns for milk and 70 microns for olive oil.
Beer, yeast slurry and cleaning chemicals are not the same as clean water, so the finish should not be specified from a generic “wet floor” assumption. The surface profile should be agreed against the actual contaminant and cleaning method. A smoother finish may clean easily but lose grip when residues remain; while a heavier profile may improve wet traction but hold soil if cleaning equipment cannot reach into the texture.
Polyurethane flooring is often a great choice for wet processing environments because it can be specified with a high degree of chemical resistance, thermal tolerance and textured finishes. The drainage calculation still comes first, however. If liquid is regularly crossing a walkway or collecting in low points, increasing texture alone does not correct the hydraulic problem; you will also need the appropriate fall gradient.
As specialist resin flooring contractors, our team install resin flooring for breweries, distilleries and wet processing environments across the UK. Please contact us today to discuss floor falls, drain interfaces, surface finish, refurbishment timing and system selection.
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