Pricing the tiling on a commercial building

Estimators price the tiling on a commercial building from the drawings, well before anyone starts on site.

An estimator works through them room by room. They turn the finishes schedule into square metres, boxes and adhesive for each tile type.

What to gather first

The Royal Institution of Chartered Surveyors (RICS) publishes the New Rules of Measurement. NRM 2 covers detailed measurement for building works. RICS published the current edition in October 2021.

Surveyors measuring floor and wall finishes to NRM 2 work from plans of each floor, the main sections through the building, the external elevations and the finishes schedules.

They also want the type, quality and size of each tile, how it is fixed or bedded, and the layout and width of the joints.

Measuring room by room

Give each room its own line, with its drawing reference, its tile and its floor and wall areas. Rooms that share a tile and a way of laying it can sit together in one zone, and the estimator sets a waste allowance for each zone.

Under NRM 2, a surveyor measures the area net, as the area in contact with the base. Openings and other voids of 1 m² or less stay in the measured area.

Wall tiling is measured up to the finished ceiling height, or to its specified height where it runs on above a suspended ceiling. It is measured behind the skirting, unless the skirting goes in before the wall finish.

Skirtings are measured in metres, with their height stated. Strips of finish 600 mm wide or less are kept apart from wider areas.

Under NRM 2 the measured area stays net, and cutting and waste count as work included in each item. The estimator adds the waste allowance to the order quantities, zone by zone.

From square metres to an order

Each tile type gets one total, made up of every zone that uses it, with that zone's waste added. Divide by the area one box covers, from the tile's data sheet, then by the number of boxes on a pallet, and round up each time.

Tiles from a later order may differ slightly in tone and calibre. Tone is the colour of a batch, and calibre is the exact size the tiles came out at. Italy's tile makers' association, in its published guidance, treats tiles of a different tone or calibre as different products, to be laid on separate surfaces.

The same guidance asks buyers to order the right quantity the first time. Where a large project does use more than one batch, it suggests storing each batch in its own place on site.

Large-format tiles and heavy loads

With large-format tiles and panels, the estimator allows for more adhesive and heavier handling.

The Tile Association, in its Tiling Guide, asks for adhesive coverage as close to full as possible under these tiles. For them, and for tiles with ribbed or deeply keyed backs, it describes floating and buttering, in which the tiler butters a thin coat of adhesive onto the back of each tile.

The estimator adds that extra coat to the adhesive quantity, along with the bed depth from the adhesive maker's data sheet.

HSE suggests mechanical help such as a sack trolley, a hoist or a pallet truck, and breaking large consignments into smaller loads. HSE explains that the law requires employers to avoid hazardous manual handling where they reasonably can, assess the risk from what remains and reduce it.

Floors in food premises

Commercial kitchens and food-production rooms have their own rules for floors.

Under Regulation (EC) No 852/2004, as it stands in UK law, food businesses must keep floors in a sound condition in rooms where food is prepared. The floors must be easy to clean and, where necessary, to disinfect.

That means using impervious, non-absorbent, washable and non-toxic materials, unless the business can satisfy the competent authority that other materials are appropriate. Where the room needs it, they must also give the floor adequate surface drainage.

The Food Standards Agency's guidance says floors and walls must be in good condition, easy to clean, disinfected, smooth, hard wearing and washable. It suggests asking the local authority for advice before choosing or changing premises.

The Tile Association bases grout choice on the tile, where it goes, the service conditions and the colour wanted. The grout classes it lists include reaction resin grout (class RG), and cement grouts with high abrasion resistance (A) or reduced water absorption (W).

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