Ordering Tile and Mortar for a Shower Pan: Cuts, Bags, and Spares

A shower pan order starts where the measurement and material records end. The takeoff gives a checked tile area and a measured bed volume; the order converts both into selling units, adds a stated allowance for cuts and mixing loss, and rounds every line up. If the pan is not measured yet, measure the pan first: an allowance added to a rough area hides measurement error instead of covering cuts. Choose the tile and bed mortar in the shower pan material guide before ordering, because the products determine the sheet coverage, the bag yield, and the batch behavior.

How much extra tile does a shower pan order?

The Tile Association, the UK tile trade body, advises 10% extra for breakages and cutting on straightforward work, and notes that larger tiles may need a higher allowance. A small-mosaic shower pan floor is straightforward work: sheets cut cleanly at the perimeter and around the drain, and most offcuts are too small to reuse. Apply the allowance to the checked net area from the measurement record, not to the gross footprint before deductions.

Use 15% when the pan layout is busy: a linear drain with envelope cuts, a drain position that forces many sheet cuts, or fragile stone that breaks more often during cutting. Treat 10% as a floor, not a target. The allowance covers cuts and breakage, not measurement; if the drain cut-out or an opening was never deducted, measure it now instead of raising the percentage. The general tile waste allowance guide covers cuts and spare stock in more depth.

Worked example: tile order for a 36 by 48 in pan

The pan floor is 36 by 48 in, a net 12.0 sq ft, covered with 12 by 12 in mosaic sheets. Each sheet covers 1.0 sq ft, and the layout is a straightforward small mosaic, so the allowance is 10%.

1. Apply the allowance: 12.0 x 1.10 = 13.2 sq ft.
2. Convert to sheets: 13.2 / 1.0 = 13.2, rounded up to 14 sheets.
3. Convert to boxes. The box holds 10 sheets. Box count: 14 / 10 = 1.4, rounded up to 2 boxes.

Result: order 2 boxes, delivering 20 sheets = 20.0 sq ft. The unrounded 13.2 sheets and 1.4 boxes stay on the record so the order can be reproduced. Keep the 6 unopened sheets beyond the 14 with the job as same-batch spares; fired tile shifts shade between batches, and an add-on order later may not match.

How many bags of bed mortar does the order carry?

Divide the measured bed volume by the manufacturer's published yield per bag, then round up to whole bags. An 80 lb bag of Quikrete Floor Mud yields about 0.66 cubic feet of packed material. Use the yield of the product actually bought; a 50 lb bag or a different brand's yield changes the count, so the product name stays on the order row. The measured volume comes from the measurement record: a 36 by 48 in pan with 0.75 in minimum thickness at the drain and 1/4 in per foot slope gives 1.0625 cubic feet per sloped layer.

1. Divide the measured volume by the bag yield: 1.0625 / 0.66 = 1.61 bags.
2. Round up to whole bags: 2 bags per sloped layer.

Result: the order row reads 2 bags per sloped layer, with 1.0625 ft3 measured. The 0.39-bag overage is the contingency. Do not add a second percentage on top of whole-bag rounding without site evidence: adding 10% to 1.61 gives 1.77, which still rounds to 2 bags, so the rounding already holds the margin that installer guides describe as extra purchase for waste, spillage, and mixing errors.

A liner build carries two sloped layers. Order the pre-slope and the bed on separate rows: 2 bags plus 2 bags, 4 bags total. A single combined row hides which layer a shortfall belongs to, and a mixing error in one layer should not stall the other.

Why should the whole tile order come from one batch?

Fired tiles shift shade between production batches. The Tile Association advises ordering from the same batch and checking the batch numbers when the delivery arrives. Cle Tile builds a minimum 15% overage into its guidance partly so a later add-on order is never needed. For a shower pan the matching problem is harder than on a backsplash: the floor is one visible field under one light, and a repair with an off-shade sheet shows every time the room is used. Keep the spare sheets from the original batch with the job, labelled with the pan they belong to.

What else goes on the shower pan order?

Size the thinset order by the manufacturer's coverage per bag for the trowel you will use; the tile adhesive coverage guide explains the method. The material guide already fixed the grout type by joint width, so order it in the maker's selling unit with the same rounding rule. Everything else on the job, such as the waterproofing, the drain assembly, and the sealant, belongs on its own rows with its own basis; this page covers the tile and the bed mortar.

How do you record the order so it can be checked?

Keep the measured number and the allowance on separate lines of the record. A single combined number cannot be rechecked: nobody can tell later what was measured and what was added.