Tile & Stone Installation

Sill and Wall Mud (821)

SGM Sill and Wall Mud 821 is a lightweight plaster substrate bedding mud that delivers reliable performance without adding extra load to structural members. It is factory blended using Portland cement, sand, and lightweight fillers for consistent quality and ready use. This product streamlines the plaster process by eliminating the need for manual mixing of sand and cement on site.
One of the greatest advantages of this product is its ability to work over a broad range of surfaces without the need for metal lath. It adheres effectively to Portland cement plaster, gypsum wallboard, concrete block, brick, and clay tile. When working over masonite, wood, metal, or plastic, installers can add metal lath to ensure mechanical bonding for added performance.
To prepare this mud, simply add approximately 1.5 gallons of cool clean water to a 50 pound bag. Mix until the mud reaches a trowel ready consistency then allow it to slake for five minutes before remixing. Applying with pressure ensures consistent mechanical contact and a uniform base, after which you float the mud to the desired thickness. Installing movement joints every two to four feet both vertically and horizontally allows for proper shrinkage control while aligning with tile joints.
This product cures quickly with a minimum cure time of 24 hours. That means tiles can be set the same day the mud is installed. With coverage of 28 to 30 square feet at a 1/2 inch thickness from a single bag, it offers efficient coverage for large or small projects.
SGM Sill and Wall Mud 821 is also designed with safety and longevity in mind. It becomes alkaline when mixed and contains free silica. Use a mixing paddle to avoid splashes, wash exposed skin thoroughly, rinse eyes immediately with water, and seek medical attention if necessary. Avoid breathing dust and always use a NIOSH approved mask when handling dry material to protect against silicosis or other respiratory hazards.
This product has a shelf life of up to one year when stored in an unopened container. SGM also backs it with a one year warranty from the date of manufacture. Defective product claims require written notice and sample submission. Beyond that coverage, warranties of merchantability or fitness for particular use are not provided.
SGM Sill and Wall Mud 821 provides a reliable lightweight substrate solution for installers who need a consistent, easy to apply mud base that is ready for tile within a day. It reduces labor time, ensures structural performance, and supports fast installations with confidence.

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Product Details

PREPARATION

SGM Sill and Wall Mud 821 may be used over the following substrates without metal lath:

  • Portland cement plaster;
  • Gypsum wallboard;
  • Concrete block;
  • Brick; or
  • Clay tile.

Metal lath is required when going over the following:

  • Masonite;
  • Wood;
  • Metal; or
  • Plastic products.

All surfaces must be clean, dry, and free of wax, grease, scaly paint, and all other foreign matter. Hence, any further cleaning shall be done using SGM Safe Clean Crystals; refer to Safe Clean Crystalslabel directions. Remove all liquid curing agents. All materials and areas to be tiled should remain above 40°F (forty degrees Fahrenheit) 24-hours prior and 72-hours after installation.

APPLICATION

Add sufficient cool, clean water to dry mix, approximately 1.5 gallons per 50 lbs. of Sill and Wall Mud. Mix until mortar becomes trowable; let material slake five (5) minutes, then re-mix. Apply Sill and Wall Mud to the surface using sufficient pressure to work mortar to form a good mechanical bond. Float Sill and Wall Mud to desired thickness (maximum of ? inch). Cut in material approximately every two (2) feet to four (4) feet both vertical and horizontal and allow for cuts to fall out on tile joints.

CURING

The minimum cure is reached in 24 hours. Tiles may be set the same day Sill and Wall Mud is applied.

COVERAGE

Twenty-eight (28) to thirty (30) square feet at ½ inch (13 mm) thickness per 50 lbs. bag.

SHELF LIFE

Up to one (1) year from date of manufacture in an unopened container.

CAUTION

Product is alkaline on contact with water. Use paddle for mixing to avoid splashing into eyes or contact with skin. During mixing or application avoid contact with eyes. In case of such contact, flood eyes repeatedly with water and CALL A PHYSICIAN. Wash thoroughly after handling and before smoking or eating. Do not take internally. CONTAINS FREE SILICA — DO NOT BREATHE DUST. Prolonged exposure to dust may cause delayed lung disease (Silicosis).

WARNING: This product may expose you to chemicals, including silica, which the State of California recognizes as a cause of cancer. For more information, visit the Proposition 65 Warnings Website (www.P65Warnings.ca.gov). Use NIOSH approved masks at all times to handle silica dust. KEEP OUT OF REACH OF CHILDREN.

FIRST AID

In case of skin contact, wash thoroughly with plenty of warm soapy water. For eye contact, flush with plenty of water for 15 minutes and get medical attention immediately. If you experience difficulty breathing, leave the area to obtain fresh air. If continued difficulty is experienced, get medical attention immediately. If swallowed, do not induce vomiting, get medical attention immediately. KEEP OUT OF REACH OF CHILDREN.

MAINTENANCE

None required.

SGM, Inc. warrants this product will perform in accordance with its intended use for a period of one (1) year from the date of manufacture. Any claim for defective product must be submitted in writing to SGM, Inc., and samples of defect must be provided. SGM, Inc.’s sole obligation will be to replace any product determined to be defective by SGM Inc. EXCEPT AS PROVIDED HEREIN, SGM, INC. MAKES NO OTHER REPRESENTATION OR WARRANTY OF ANY KIND, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR PARTICULAR PURPOSE. IN NO EVENT SHALL SGM, INC. BE LIABLE FOR DAMAGES OF ANY KIND OR NATURE, WHETHER ARISING BY CONTRACT, TORT OR OTHERWISE. SGM, INC.’S SOLE OBLIGATION WILL BE TO REPLACE ANY PRODUCT DETERMINED BY SGM, INC. TO BE DEFECTIVE.