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types of construction sand

Types of Construction Sand: River Sand, Washed Sand and Manufactured Sand, and How to Pick One

River sand, washed sand and manufactured sand compared: gradation, fines, chlorides and workability, with S1/S2 trade terms and how to pick the right sand.

Published Updated 9 min readBy Stone Depot TradingReviewed by Stone Depot Trading team

Sand is a large share of the volume of most concrete and almost all of a plaster coat, yet it is often ordered with a single word. The wrong sand shows up as a harsh mix that will not finish, a plaster that cracks, or reinforcement that corrodes years later. This guide explains the main types of sand sold in the Philippines, what the trade names mean, and how to choose by intended use.

What "good sand" means

For concrete and mortar, sand is judged on five things:

  • Gradation. A spread of sizes from about 4.75 mm down to 150 µm. ASTM C33 gives the envelope and requires a fineness modulus (FM) between 2.3 and 3.1; coarser sand within that range suits concrete, finer sand suits plaster.
  • Fines. Material passing the 75 µm sieve: silt, clay and dust. ASTM C33 limits it to 3.0% for concrete subject to abrasion and 5.0% for other concrete, rising to 5.0% and 7.0% for crushed sand where the fines are dust of fracture free of clay or shale.
  • Cleanliness. No clay lumps, organic matter, coal or shells beyond the limits in ASTM C33 and, for DPWH work, the DPWH aggregates item named in the contract.
  • Chlorides and salts. Sea-derived sand can carry enough chloride to corrode reinforcement; ACI 318 limits the water-soluble chloride in the concrete, and the sand is often the main contributor.
  • Particle shape. Rounded grains flow easily; angular grains interlock and need more water or admixture for the same slump.

Every type of sand below is a different balance of these five.

River sand

River sand is natural sand dredged or dug from river beds and banks. The water has already done a rough job of washing and rounding it, so good river sand is workable, well-graded and low in dust. It has been the default concrete and plaster sand in the Philippines for generations.

Its weaknesses are variability and supply. Gradation changes along the same river and after every flood; silt and clay come with it in slow-water stretches; organic matter is common near vegetation. Extraction is regulated: under the Philippine Mining Act (RA 7942) commercial sand and gravel permits are issued by the provincial governor and industrial sand and gravel permits by the Mines and Geosciences Bureau for larger areas, and the province may tax the material under Section 138 of the Local Government Code, so supply from a given river is not guaranteed in every season. Buy river sand on a fresh sieve analysis and silt check rather than on last month's delivery, and ask the source what current results it holds before ordering; where none exist, the test has to be arranged.

Washed sand

Washed sand is river, pit or crushed sand that has been screened and washed to remove silt, clay, dust and light organic matter. The result is cleaner and more consistent, with lower water demand and less risk of shrinkage cracking. It is the sand most batching plants and plasterers want.

Two things to know when buying it:

  • It arrives wet, and damp sand bulks: the same mass occupies noticeably more volume when damp, fine sand most of all. A truck-bed measurement of wet sand therefore contains less dry sand than the same volume dry, and a weighbridge ticket includes the water. Agree the unit and a moisture allowance in advance.
  • "Washed" is a process, not a grade. A washed sand can still be too fine for concrete or too coarse for a smooth plaster finish. Ask for the gradation.

Manufactured sand (crushed sand)

Manufactured sand, also called M-sand or crushed sand, is produced by crushing rock (basalt, andesite, limestone or river gravel) and screening the product below 4.75 mm. It fills the gap as river sources tighten, and it is already standard in many ready-mix plants.

Advantages:

  • Consistent gradation, because it comes from a crusher setting, not a river.
  • No organic matter, shells or sea-derived chlorides.
  • Angular grains that interlock and bond well with paste.

Disadvantages:

  • Higher fines from crushing. ASTM C33 allows up to 7.0% for concrete not subject to abrasion when the fines are dust of fracture free of clay or shale, but they must be checked for plasticity.
  • Harsher workability with poorly shaped particles, especially from crushers without a shaping stage. Well-shaped M-sand from a vertical-shaft impact crusher is much better, and admixtures close the rest of the gap.
  • Mix designs from river sand do not transfer directly; water demand and sand ratio usually change.

Ask which rock it comes from; limestone sand is softer and dustier than basalt sand.

Sands to treat with caution

  • Beach and sea sand carries chloride and shells. It can only be considered after thorough freshwater washing and a chloride test (ASTM C1218 for water-soluble chloride, or the acid-soluble method ASTM C1152 if the project specifies it), and untreated beach sand should not go into reinforced concrete. Extraction from beaches is regulated under the mining laws and is often not permitted at all; ask for the source's permit.
  • Pit or hill sand may carry clay coatings that never wash off in the mixer; check the fines and their plasticity.
  • Fine white coral sand, sold in some coastal areas as a plaster or finishing sand, is usually too fine and too weak for structural concrete.

Trade terms: S1, S2 and other local names

Philippine hardware stores and yards use short codes that are not defined in any standard, and their meaning shifts between provinces and even between yards. The meanings below are common local usage only:

Trade term Usual local meaning (not standardised)
S1 Finer sand, generally sold for plastering, finishing and CHB laying
S2 Coarser sand, generally sold for concrete and masonry
Washed sand Sand that has been screened and washed; grade varies
Vibro sand Crushed (manufactured) sand, a term used in some areas
White sand Fine, light-coloured sand, often coral-derived, used for plaster

Because these codes vary, the safe way to order is to name the intended use and the standard: "concrete sand, ASTM C33, FM about 2.7, fines under 3%" or "plaster sand, fine, washed, no organics". Local codes can go in brackets.

Picking the sand by use

Intended use Sand to ask for Key properties
Structural concrete, ready-mix, slabs Concrete sand: washed river sand or well-shaped M-sand ASTM C33 envelope, FM toward the coarse end of 2.3–3.1, fines within the C33 limit, low chloride; consistent FM between deliveries
Masonry mortar, CHB laying Mortar sand to ASTM C144 Graded within the C144 limits, clean
Plastering Fine washed sand or fine M-sand Finer than concrete sand, no organics, no shells, low fines
CHB and paver manufacture Medium to coarse sand, often blended with crushed fines Consistent gradation for a dry-cast mix
Paver bedding Coarse washed sand, 0–5 mm Sharp, well-drained, no fines that hold water
Backfill and pipe bedding Fill sand Free of stones and debris; cleanliness less critical

The grading envelopes themselves are in aggregate gradation for DPWH specifications.

Field checks before accepting a delivery

A delivery can be screened in minutes before the laboratory result arrives:

  1. Silt jar test. Fill a clear bottle one-third with sand, top up with water, shake and let it settle for an hour. A thick silt layer over the sand is a signal to hold the delivery pending a proper ASTM C117 wash test; set the threshold in your own QC plan.
  2. Rub test. Rub damp sand between the palms; clay leaves a stain and a sticky feel.
  3. Look and smell. Dark colour, roots, leaves or a sour smell point to organic matter; run the ASTM C40 colour test.
  4. Shells and salt. Visible shells and a salty taste on the fingers mean sea-derived sand; require a chloride test before use in reinforced concrete.
  5. Compare with the approved sample. Keep a labelled jar of the approved sand at the plant.

The laboratory tests behind these checks are explained in quality checks for batching-plant aggregates.

How Stone Depot Trading helps

Stone Depot Trading coordinates B2B sourcing and supply of sand, gravel, limestone and fly ash through trade partner companies from General Santos City; it does not run a pit, a washing plant or a laboratory. State the intended use, the type or grading, the volume and the delivery schedule, and say which reports your specification requires — a sieve analysis, a fines result, a chloride test. Source, availability, price and delivery terms are confirmed before quotation, and what a source can supply in the way of test documents is asked of it and reported back before you order, because that varies with the material, the source and how it was tested. Gravel is covered separately in gravel sizes explained.

FAQ

Which sand is best for concrete?

A clean, well-graded sand toward the coarse end of the ASTM C33 fineness modulus range, with fines below the C33 limit. Both washed river sand and well-shaped manufactured sand can meet this; the mix design must be checked for whichever is used.

Can manufactured sand fully replace river sand?

Yes, in most concrete and masonry applications, provided the fines are clean, the particle shape is acceptable and the mix design is adjusted. It is already standard in many plants.

What do S1 and S2 mean?

In common local usage S1 is the finer plastering sand and S2 the coarser concrete sand, but the codes are not standardised. Specify by use and gradation.

Is beach sand acceptable for construction?

Not for reinforced concrete unless it has been thoroughly washed with fresh water and tested for chloride. Even then, shell content and fineness can make it unsuitable, and the source must hold a valid permit.

Why is my sand delivery smaller than the volume ordered?

Wet sand bulks; loose volume in the truck is larger than the volume after it dries or compacts. Agree the unit of measure and a moisture allowance before delivery.

Request a quote

Send the intended use, the type or grading, the volume and the delivery location and schedule through the quote form, by email to cjandulana@stonedepotph.com, or by call or Viber to +63 945 643 5233. Submitting an inquiry starts a sourcing conversation; it does not create a binding order.

Sources

Disclaimer

This article is general information. Final suitability of any material must be confirmed against the buyer's project specifications, the approved mix design, laboratory test results and the project engineer's requirements. Stone Depot Trading coordinates sourcing and supply; it does not certify materials or guarantee acceptance by any agency.