For clay roof tiles, the questions that matter are whether water passes through the tile and how much load it carries before it breaks. In Europe these are set by EN 1304, the product standard for clay roofing tiles and fittings, with EN 538 for flexural strength and EN 539-1 for impermeability.
Water absorption on its own matters less than for floor tiles. A roof tile can absorb some water and still keep a roof dry. What it must not do is let water through, crack under load, or break up when frozen.
The European standards
EN 1304 is the product standard. It defines tile types, sets the requirements and points to the test methods. The current edition is EN 1304:2013, sold by national standards bodies such as BSI.
- EN 538 sets the flexural strength test. A tile is supported and loaded until it breaks, and the breaking load is recorded in newtons.
- EN 539-1 sets the impermeability test. It measures how much water passes through the tile over a set time, using one of two methods the standard treats as equivalent.
- EN 539-2 sets the frost resistance test, which has several methods; see whether Indian clay roof tiles are frost-resistant.
Impermeability categories
EN 1304 sorts tiles into impermeability categories based on the EN 539-1 result. Category 1 is the stricter class. Tiles in the lower category are meant for roofs with a watertight underlay beneath them.
National rules can narrow this further. The UK foreword to BS EN 1304, for example, says only Category 1 tiles tested by a specific method should be used in the UK. Check your own country's national foreword before you accept a test report.
Breaking strength
EN 1304 sets a minimum breaking load that depends on the tile type. Plain tiles, flat interlocking tiles and deeply profiled tiles have different minimums, because their shapes carry load differently.
We do not quote the minimums here, because they depend on the edition and the exact tile type. Ask the lab to report the result against the EN 1304 requirement for your tile type and to state which type it used.
Water absorption
Many Indian makers quote a water absorption figure for clay roof tiles. It is a useful sign of how well the tile was fired. A well-fired tile usually absorbs less water and is stronger than an underfired one from the same clay.
But absorption is not the European pass or fail test for roof tiles. Treat it as a control figure. Ask for it on every batch, and compare it with the value on the sample that passed your strength and impermeability tests. A big jump suggests the kiln was run differently.
How to use this when buying
- Ask which standard the maker has tested to, and for the full test report, not a summary sheet.
- Make sure the lab tested tiles from a real production run and lists the number of tiles tested.
- For the EU, ask whether the maker can issue a Declaration of Performance under EN 1304; without one, CE marking is not possible.
- Outside Europe, use EN 1304 or your national standard as the reference in your contract, and say which one.
- Order a fresh test on a sample drawn from your own lot, as described in reading a lab certificate.
Next step
We pick test samples from your production lot and send them to an accredited lab before loading. For the product background, see what roofing tiles are made in Morbi. To set up testing for your order, book a free sourcing review.