Understanding the result
Plan reclaimed tile or brick quantities before a layout starts. The estimate uses a regular module of one unit plus a grout or mortar joint and adds waste based on the pattern selected. Old stock often has uneven dimensions, damaged edges and colour variation, so sort and dry-lay representative units before relying on a purchase quantity.
- These results support research and planning; they do not independently establish authenticity, age or value.
- Keep direct observations separate from assumptions, seller claims and conclusions.
- Seek qualified, object-specific advice when the decision affects value, repair, safety or a legal transaction.
Good records improve research
Keep original observations separate from conclusions. Photograph the whole object and relevant details in even light; record dimensions, labels, maker marks, repairs, provenance and the references consulted. Do not alter the object just to obtain another clue.
Methodology and limitations
Usable surface area is divided by the repeated module area. Joint width is converted to centimetres, and the selected layout factor plus user waste allowance increases the initial count. The calculator rounds up to whole units, compares required quantity with usable stock and reports the likely surplus or shortfall. Irregular paving, borders, cuts and complex bond patterns may need a separate layout plan.
A 20 m² floor using 10 × 10 cm tiles with 4 mm joints has a base requirement of roughly 1,850 modules before adding breakage and layout allowances. Verify with a dry layout because actual antique tiles vary in size.
Historical objects are often repaired, refinished, reassembled or made from more than one material. Modern reproductions may imitate older processes. A likely match should always be phrased as a research hypothesis unless it is supported by a qualified, object-specific assessment and trustworthy documentation.
Frequently asked questions
Why include joint spacing in module area?
Each laid unit uses its own dimensions plus part of the repeated joint. Ignoring joint width can undercount the area coverage, particularly for small units.
Does the calculator account for irregular antique tiles?
Only through your chosen waste allowance. Sort pieces, measure a representative sample, and increase the allowance where sizes, thicknesses or edge conditions vary substantially.
What waste allowance should I use?
There is no universal percentage. Cuts, pattern complexity, fragile edges, colour sorting and future matching stock all affect the amount. Use a conservative allowance agreed with the installer.
Why does running bond need extra material?
Staggered rows can create more edge cuts than a straight grid, especially around rooms, thresholds and obstacles. The pattern factor is a planning assumption, not a guarantee.
Can I use this for bricks with variable lengths?
Use a representative average only for a rough estimate. Irregular reclaimed brickwork is better planned from sorted dimensions and a trial layout.
Related antique tools
Continue with relevant measurement, condition and material research tools.