🛣️ Determination of the water absorption coefficient due to capillary action (aggregate concrete, autoclaved aerated concrete, manufactured and natural stone units) and the initial rate of water absorption (clay units) — at least 6 specimens dried to constant mass at 70 °C or 105 °C, the test face immersed to a depth of (5 ± 1) mm for the time given in the product standard (1 min for clay), the increase in mass related to the face area and time or the square root of time, PN-EN 772-11

Construction PN-EN 772-11

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in the iTeh sample of SIST EN 772-11:2011 (text of EN 772-11:2011, English): from the title page through the contents, foreword and Clauses 1–9 up to and including Clause 10 (test report, items a–i) on page 7. Outside the sample remains Annex A (significant technical changes compared with the previous edition).

ACCORDING TO THE TEXT OF EN 772-11:2011 (foreword, Clauses 1–10). The standard was prepared by CEN/TC 125 “Masonry” (secretariat BSI); CEN approved it on 25.12.2010, and it superseded EN 772-11:2000. Scope (1): the water absorption coefficient due to capillary action for aggregate concrete, autoclaved aerated concrete, natural stone and manufactured stone masonry units and the initial rate of water absorption of clay masonry units. References (2): EN 771-1 to EN 771-6, EN 772-16. Principle (3): after drying to constant mass, one face of the unit is immersed in water for a specific time and the increase in mass is determined; for clay units the initial rate of absorption of the bed face is measured, for the others the absorption of the face to be exposed, as described in the product standard. Apparatus (5): a tray at least 20 mm deep with a plan area larger than the face to be immersed, with a means of maintaining a constant water level; supports with a plan area of at most 400 mm2 keeping the specimen clear of the base; stopwatch graduated in seconds; ventilated oven maintaining (70 ± 5) °C (aggregate concrete, aerated concrete, natural and manufactured stone) or (105 ± 5) °C (clay); balance accurate to 0,1 % of the dry specimen mass. Specimens (6): sampling according to the relevant part of EN 771; at least six specimens unless the product standard requires more; drying to constant mass mdry,s at 70 °C or 105 °C — constant mass when two subsequent weighings 24 h apart differ by at most 0,1 % of the total mass. Procedure (7): cool at room temperature, measure the dimensions of the face to be immersed according to the principle of EN 772-16 and calculate the gross area As; place the specimens on the supports and immerse to (5 ± 1) mm for the whole test; for an extremely irregular face raise the water level so that the whole surface just touches the water; for natural stone record whether the face is parallel or perpendicular to the bedding planes; keep the water level constant; for concrete, aerated concrete and stone units cover the tank to avoid evaporation; after the immersion time tso from EN 771-1, EN 771-3, EN 771-4, EN 771-5 or EN 771-6 remove, wipe off surface water and weigh (mso,s); natural stone is removed, wiped and weighed at regular intervals until there is no further increase in mass; for some clay units the two bed faces may differ in initial rate of absorption, and both must be measured. Calculation (8): aggregate concrete and manufactured stone — cw,s = (mso,s − mdry,s) / (As · tso) × 10⁶ g/(m2 · s), to 0,1; aerated concrete and natural stone — cw,s = (mso,s − mdry,s) / (As · √tso) × 10⁶ g/(m2 · s0,5), to 1; for natural stone cw,s is the gradient of the initial linear portion of the graph of (mso,s − mdry,s)/As against the square root of time; clay — cwi,s = (mso,s − mdry,s) / (As · t) × 10³ kg/(m2 · min), t = 1 min, to 0,1. Evaluation (9): mean of the specimens to the same precision. Test report (10): among others the date of testing (concrete, aerated concrete, manufactured stone), description of specimens according to EN 771, number of specimens and whether they are whole units or representative portions, individual values, immersion time and means; for natural stone — the position of the face relative to the bedding.

STATUS (as of 03.10.2026). The PKN search (term “PN-EN 772-11”, 03.10.2026) shows 5 items: PN-EN 772-11:2011 in the English and German versions (“Introduces: EN 772-11:2011 [IDT]”) without a withdrawal note, and the withdrawn PN-EN 772-11:2002 (Polish version) and the additional element PN-EN 772-11:2002/A1:2005 (Polish and English versions), replaced by PN-EN 772-11:2011. In the iTeh catalogue (read on 03.10.2026) EN 772-11:2011 has the status “Published” and stage 90.93 “Decision to confirm — Review Enquiry” (start date 23.01.2025); it replaced EN 772-11:2000/A1:2004. The density of masonry units is described in the entry on PN-EN 772-13, dimensions in the entry on PN-EN 772-16, and cold water absorption in the entry on PN-EN 772-21.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read on 03.10.2026). The number 772-11 appears in 7 records at 5 laboratories: AB 011, AB 023, AB 054 (3 records), AB 251, AB 687. In the current PCA documents (read on 03.10.2026, issues from 16.07.2025 to 13.08.2026) the number appears in 7 rows of the same laboratories (AB 054 — 3, the others 1 each; the PDF file of the AB 251 scope contains the same document twice — we count it once). The form “PN-EN 772-11:2011” (AB 054, AB 251, AB 687) and “PN-EN 772-11” without year (AB 011, AB 023 — in the flexible scope “E”). None of these items is suspended (AB 054 has a suspension in another part of its scope). The “Laboratories” tab (“PN-EN 772-11”) shows the same 5 laboratories — checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA). Initial rate of water absorption — clay masonry units (AB 251, AB 687) and masonry units without further specification (AB 011, scope “E”). Water absorption — aggregate concrete masonry units (small-format wall units) and autoclaved aerated concrete (AB 054); water absorption by capillary action — absorption coefficient, lintels excluding steel lintels, gravimetric method, range (0–10) g/(m2 · s) (AB 054); absorption by the capillary rise method, range up to 30 %, gravimetric method — masonry units of aerated concrete, calcium silicate, clay, concrete, gypsum and others (AB 023, scope “E”). Calcium silicate and gypsum units are not among the materials of Clause 1, and the standard expresses the result in g/(m2 · s), g/(m2 · s0,5) or kg/(m2 · min), not in percent.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. With drying: 70 °C for concrete, aerated concrete and stone, 105 °C for clay; constant mass after two weighings 24 h apart with a difference up to 0,1 % (5.4, 6.2). With immersion: (5 ± 1) mm throughout, constant water level, tank covered except for clay (7). With the face: for clay the bed face (sometimes both), for the others the exposed face according to the product standard (3, 7). With time: tso from the product standard, for clay t = 1 min; for aerated concrete and natural stone the formula with the square root of time (8.2). With natural stone: weighings until the increase stops and the gradient of the initial portion of the graph, position relative to the bedding (7, 8.2). With the number of specimens: at least 6 (6.1).

WHAT WE DO NOT GIVE. We did not read the content of Annex A (technical changes compared with the 2000 edition). Nor do we give immersion times or requirements from the EN 771 product standards.

Method principle

A masonry unit dried to constant mass (70 °C or 105 °C) is placed with the test face on supports in a tray of water, immersed to (5 ± 1) mm, and weighed after the time given in the product standard (1 min for clay). The increase in mass divided by the gross face area and the time (or the square root of time) gives the capillary absorption coefficient or the initial rate of water absorption; the result is the mean of at least 6 specimens.

Applications

• Aggregate concrete, autoclaved aerated concrete, manufactured and natural stone masonry units — capillary absorption coefficient (1)
• Clay masonry units — initial rate of water absorption of the bed face (1, 3)
• Masonry units, including clay, concrete and aerated concrete units, and lintels — items in the accreditation scopes of 5 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN 772-11:2011

Title (PL)

Metody badań elementów murowych — Część 11: Określenie absorpcji wody elementów murowych z betonu kruszywowego, kamienia sztucznego i kamienia naturalnego spowodowanej podciąganiem kapilarnym oraz początkowej absorpcji wody elementów murowych ceramicznych

Title (EN)

Methods of test for masonry units — Part 11: Determination of water absorption of aggregate concrete, autoclaved aerated concrete, manufactured stone and natural stone masonry units due to capillary action and the initial rate of water absorption of clay masonry units

Step-by-step procedure

1. Specimens

   At least 6 according to EN 771; drying to constant mass at 70 °C or 105 °C. PN-EN 772-11:2011 without a withdrawal note (03.10.2026).

2. Measuring the face

   After cooling, measure the immersed face according to the principle of EN 772-16, calculate the gross area As.

3. Immersion

   On supports, to (5 ± 1) mm; constant water level; tray covered (except for clay).

4. Weighing

   After time tso (clay 1 min) wipe the face and weigh; weigh natural stone cyclically until the increase stops.

5. Result

   Coefficient from the appropriate formula for each specimen and the mean.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Heavy masonry units — lifting and placing in the tray following safe working practices
• Hot specimens after drying at 105 °C — hand protection

Frequently asked questions