Hamilton Drywall Products

Finishing and Texturing Gypsum Drywall Walls and Ceilings

1. Scope

Unless otherwise indicated, all walls, partitions and ceilings on which gypsum wallboard has been applied, are included. The levels of finish on these surfaces have been defined in accord with "Recommended Levels of Gypsum Board Finish" (GA-214). Contractor is to furnish all labor and material necessary to produce a smooth, monolithic surface suitable for application of the specified decorative finish. (See Finish Schedule)

1.1 Reinforce and conceal all joints between gypsum wallboard panels.

1.2 All corner reinforcement (cornerbead; metal, or other) is to be finished to a smooth, even plane, using only those compounds recommended for that purpose by the manufacturer.

1.3 All exposed fastener heads are to be concealed and finished smooth.

2. Job Conditions

2.1 No materials shall be applied until a minimum temperature of 50° F has been maintained for a period of at least 48 hours in the working area and the surface moisture has been stabilized (dry). The same conditions shall be maintained during the complete finishing operation and until all materials are completely dry and stable. Provide adequate ventilation to insure proper drying, setting, or curing conditions.

3. Materials

3.1 All finishing materials shall be the products of Hamilton Drywall Products. (See Hamilton Finishing System Selector Guide)

3.2 Materials to be delivered to job site in original, unopened containers, and stored in a location protected from weather and tampering.

4. Application

4.1 Mixing and/or thinning of joint compounds shall be done in accordance with Hamilton’s recommendations, which appear on each container. Intermixing of chemically hardening and drying materials is not recommended.

4.2 Reinforcement of field and interior angle joints shall be accomplished by embedding drywall tape directly over the joint in a coat of the recommended joint cement (or taping system) approximately three inches in width. The tape should be firmly seated in the joint cement, wiped smooth, and excess joint cement removed. (Sufficient cement is to be applied to insure proper bond of the tape and fill the wallboard recess.)
Note: In all operations, allow each coat of joint cement to dry thoroughly before applying subsequent coats.

4.3 Second, or skim coat, to be applied to a width of approximately seven inches, centered over the joint, and drawn to a smooth, even plane with the wall board surface.

4.4 If required, a third coat shall be applied to a width of approximately ten to twelve inches, centered over the joint, and drawn to a smooth, even plane.

4.5 Fastener heads shall be covered with at least two coats of joint cement allowing sufficient drying time between coats.

4.6 All cut-outs around pipes, vents, receptacles, etc., shall be back filled with joint cement and when necessary, reinforced with joint tape.

Note: Special treatment is sometimes required on fire resistive wall/ceiling assemblies. Consult the uniform Building Code or responsible agency for requirements.

4.7 All corner reinforcing, as well as exposed flanges of trim, shall be concealed with at least two coats of the recommended joint cements and finished smooth.

4.8 Where necessary, the dried joint cement surfaces may be lightly sanded to insure a smooth surface. Care should be taken not to raise the nap of the wall board face paper. All sanding dust is to be removed. Approved protective respirators should be worn while mixing powder or sanding. Sponging is recommended where practical.

4.9 For wall or ceiling surfaces to be finished with gloss paints, or subject to severe lighting conditions, a thin skim coat of joint cement or Hamilton's Prep Coat Plus shall be applied to the entire surface of the board. This is particularly important on smooth, untextured surfaces. (See Level of Finish)

5. Texturing

5.1 Surfaces to receive texture should be treated to minimize variances between joints and field of board. Hamilton's Prep Coat Plus is recommended for that purpose. If water-soluble contaminants are suspected on the substrate, the application of a sealer is recommended to prevent discoloration.

5.2 Samples of texture pattern and coverage to be submitted for architectural approval prior to application.

5.3 Masking (optional) – All door frames, windows, and window frames are to be masked prior to application of textures.

5.4 Clean-up (optional) – Remove masking from area not to receive texture. Floors are to be scraped and left broom clean.

6. Decoration

6.1 Acceptability of surfaces for decoration and proper application of those decorative products are the responsibility of the appropriate contractor (paint, wall covering, etc.)

Note: Method of application of paint products can be critical. Roller application has proven to be the most satisfactory over drywall surfaces.