ProMasonry Cement Products

Data Sheet | SDS


ProMasonry Glass Block Mortar is a precise blend of cement, lime and aggregates mixed with polymer and other additives to provide a durable waterproof joint.

For laying glass block, brick, concrete block or stone.


  • Resistant to mold growth.
  • Can be used for tuck pointing.
  • Can be used for interior or exterior applications.

Surfaces must be clean, sound and frost free.

  • Remove any contamination that would inhibit bond such as oils, grease, dust, etc.
  • Prepare the glass block per the manufacturer's instructions.

Add 4 - 5 quarts of clean water to a mortar mixer. Slowly add 1 bag of the Glass Block Mortar to the mixer and mix slightly stiffer than mortar-like consistency (A stiffer than mortar-like consistency is recommended as glass block will not absorb water like a typical CMU).

  • Add clean, potable water as needed to achieve desired consistency, but do not exceed 5 quarts total.
  • Mix for 5 minutes. Do not re-temper.

Prepare sill per glass block manufacturer's specifications.

  • Apply a full mortar bed joint to sill. Set lower course of block.
  • Maintain a uniform joint width of 1/4 to 3/4 inch plus or minus 1/8 inch. Use only wooden or rubber tipped tools when tapping glass blocks in place. Do not realign, tap or move block after initial placement.
  • Set succeeding courses of block. Space at head of panel and jambs must remain free of mortar for caulking.
  • Strike joints smooth while mortar is still plastic and before final set. Tool joints smooth and concave before mortar takes final set.
  • Refer to the glass block manufacturer's specifications for recommended installation instructions.

Mist curing may be required in very hot or windy conditions. Protect from direct sunlight, wind, rain and frost during curing period.

Remove surplus mortar from the faces of the glass block at the time joints are struck or tooled. Mortar should be removed while it is still plastic using a clean, wet sponge or an ordinary household scrub brush with stiff bristles.

  • Never use a wire brush to remove mortar from glass block surfaces. To remove the dry powder or stains from the glass surfaces; use a clean, dry, soft cloth or extra-fine steel wool.
  • Clean tools and equipment with water immediately after use.
  • Cured material will need to be mechanically removed.


Physical state and appearance :
Dry white powder

Water/cement ratio:

Specific Gravity:
Wet mix 1.95

Air content:
8 - 10%

Water retention test:
75% minimum

Compressive strengths – psi:
(ASTM C109)
7 Days 3,100
14 Days 4,000
28 Days 4,600

Wet Cure +0.02%
Dry Cure -0.09%

0.42 ft.3/50 lbs.
One 50 lb. bag will lay approximately:

  • 36 - 6 inch block with 3/8 inch joint.
  • 30 - 8 inch block with 3/8 inch joint.
  • 16 - 12 inch block with 3/8 inch joint.

50 lbs. multi-wall, poly lined bags.
Shelf Life - 12 months when properly stored.
Storage - Transport and store in cool, clean, dry conditions in unopened containers.
High temperature or high humidity will reduce shelf life.

Product is alkaline. Do not ingest. Avoid breathing dust. Avoid contact with skin and eyes. Refer to Material Safety Data Sheet (MSDS) for additional information. Keep out of reach of children.

In case of skin contact, wash thoroughly with soap and water. For eye contact, flush immediately with a high volume of water for at least 15 minutes and contact a medical professional. For respiratory problems remove person to fresh air.

Dispose of material in accordance with local, state or federal regulations.

Conproco Corp. warrants this product for one year from date of installation to be free from manufacturing defects and to meet the technical properties on the current technical data sheet if used as directed within shelf life. User determines suitability of product for use and assumes all risks. Buyer's sole remedy shall be limited to the purchase price or replacement of product exclusive of labor or cost of labor. February 2008 NO OTHER WARRANTIES EXPRESS OR IMPLIED SHALL APPLY INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. CONPROCO CORP. SHALL NOT BE LIABLE UNDER ANY LEGAL THEORY FOR SPECIAL OR CONSEQUENTIAL DAMAGES.