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ASTM C1019 is the standard test method for sampling and testing grout used in masonry. It covers both field and laboratory sampling and the compression testing of grout specimens. It is the method that turns a batch of masonry grout into a strength result, while a separate specification, ASTM C476, defines what the grout itself must be.
Short answer
ASTM C1019 (the ASTM store lists C1019-26 as the active edition, with C1019-24 dated 2024-06-18 now marked historical) is the “Standard Test Method for Sampling and Testing Grout for Masonry.” It is a method for taking grout samples, forming specimens and compression testing them. It does not set the strength a grout must reach; that sits in the grout specification, C476.
Definition and scope
According to the ASTM scope statement, the method “covers procedures for both field and laboratory sampling and compression testing of grout.” Grout, in this context, is described as a fluid mixture of cementitious materials and aggregate with a high water content. The grout requirements themselves are in Specification C476, which C1019 cites.
ASTM also states two uses. The result can help select grout proportions, or it can serve as a quality-control check that grout preparation is uniform. Searchers also write the standard as “astm c 1019”; both spellings refer to the same document, C1019.
How it is used in practice
The distinctive feature of the method is how the specimens are formed. Per the ASTM abstract of the 2016 edition (C1019-16, now historical), the molds are made from masonry units whose absorption matches the units used in the wall. The absorbent mold draws excess water out of the specimen, so the strength measured better reflects the grout as it behaves inside a masonry wall. The same text notes that this reproduces absorption conditions similar to the wall, but not the exact exposure and curing conditions.
A published laboratory summary from Geocomp describes the surrounding workflow as slump measured to ASTM C143, temperature to C1064, three specimens of 3 x 3 x 6 inches, molds removed within 24 to 48 hours, moist-room curing, and compression testing to C39. This is a third-party summary, and the numbers and referenced editions should be confirmed against the licensed text of the current standard before they are written into a laboratory procedure.
The standard is written in inch-pound units, with SI values given for information only (C1019-16, section 1.2). A laboratory that turns this into a bench procedure would normally capture it in a controlled standard operating procedure.
Related standards: who defines, who tests
C1019 sits in a small family of documents. The table below draws on the ASTM store pages for C1019 and C476, and on the C1093 reference in C1019 itself.
| Standard | What it is | Role relative to C1019 |
|---|---|---|
| ASTM C1019 | Test method for sampling and testing grout for masonry (C1019-26 active; Committee C15, Subcommittee C15.20) | Defines how grout is sampled and compression tested |
| ASTM C476 | Specification for grout for masonry (C476-23, Committee C15.30) | Defines the grout: fine and coarse types, each conventional or self-consolidating, specified by proportions or by strength |
| ASTM C1093 | Practice for the evaluation of testing agencies | C1019 states that the agency performing the test should be evaluated in accordance with C1093 |
The short version: C476 says what the grout is, C1019 says how it is sampled and measured, and C1093 is the reference for judging whether the agency doing the measuring is competent. For laboratories working under a general quality system, the accreditation route is a separate question; see our guides on ISO/IEC 17025 and on laboratory accreditation bodies.
Where it matters for labs and testing agencies
A lab-side checklist for a C1019 compression-test report or request. The first four points come from the ASTM pages above; the last is general laboratory practice:
- Edition. Name the edition year of C1019 used. The ASTM store lists C1019-26 as active and shows C1019-24 and C1019-16 as earlier editions; check the store for the edition in force before citing.
- Governing specification. Record the grout specification the grout was supplied against (for example C476, which covers fine and coarse, conventional and self-consolidating grout).
- Testing agency. Record that the agency performing the test was evaluated under C1093, as the method recommends.
- Specimen basis. State that specimens were molded in absorbent masonry-unit molds, which is what makes the result comparable to the method’s intent.
- Instruments. Compression machines and measuring devices used for the test need current calibration records.
Common misunderstandings
It is not a test of cores taken from a wall
The method carries an explicit note that results of grout specimens taken from a wall should not be compared to results obtained with this test method. The molded specimens are a controlled proxy, not a measurement of in-place strength.
It is not the grout specification
C1019 does not set a required strength or a mix. Those requirements live in C476.
It is not a generic cementitious-material test
C1019 is a method for masonry grout. Its specimens are molded in absorbent masonry-unit molds so that excess water is removed, as the method describes; that mold requirement is specific to this method.
FAQ
What is ASTM C 1019?
It is the same standard as ASTM C1019, the test method for sampling and testing grout for masonry, covering field and laboratory sampling and compression testing of grout.
Sources
- ASTM International, C1019-26 (active edition), Standard Test Method for Sampling and Testing Grout for Masonry, store abstract: https://store.astm.org/c1019-26.html (checked 2026-10-29).
- ASTM International, C1019-24 (earlier edition), store abstract: https://store.astm.org/c1019-24.html (checked 2026-10-29).
- ASTM International, C1019-16 (earlier edition), store abstract: https://store.astm.org/c1019-16.html (checked 2026-10-29).
- ASTM International, C476-23, Specification for Grout for Masonry: https://store.astm.org/c0476-23.html (checked 2026-10-29).
- Geocomp, Standard Test Method for Sampling and Testing Grout (laboratory summary): https://www.geocomp.com/tests/standard-test-method-for-sampling-and-testing-grout/ (checked 2026-10-29).
