Chapter 5: Interior Construction

INTERIOR CONSTRUCTION:

Partitions:

3 Types Mainly Used

Ø       Gypsum Wallboard

Ø       Lath and Plaster

Ø       Masonry

GYPSUM WALLBOARD:

Ø       Commonly available in 4 ft wide sheets

Ø       Available in lengths of 8, 10, 12 and 14 ft.

Ø       There is one manufacturer that does produce 4 ½ ft wide product to reduce the number of joints.

Ø       Thicknesses range from a ¼” to 5/8”

Ø       There is a 2hour fire rated Gyp Board that is ¾” thick. This allows for a 2 hour rated partition using one layer of gyp.

GYPSUM ASSOCIATION (GA-214-CCD, Recommended Levels of Gypsum Board Finish)

Level 0 – No Taping, Finishing or Accessories

Level 1 – Used For Plenums or Places you wont see the Gyp Board

Level 2 – Used where water resistant (where finish is not seen)

Level 3 – Two Coats of joint compound – used where finishes are heavy or Medium textured.

Level 4 – Three Coats of Joint Compound – used for light textures or wall covering

Level 5 – Thin skim coat of joint compound applied over the entire surface. – Used for paint finish.

WOOD STUDS:

2” x 4” or 2” x 6”

METAL STUDS

(C- Shaped Channel)

 1 5/8”, 2 ½”, 3 5/8”, 4, and 6 in.

Hat-Shaped Furring Channels (Hat Channel). (furring our walls)

Most commonly used stud is 2 ½”

Most Studs are spaced 16” OC or 24” OC.

Note:

Typical 5/8”  thickness applied in commercial

Typical ½” thickness is applied in residential. 

GYPSUM WALL BOARD TRIM:

Ø       LC Bead: Requires Joint Compound

Ø       L Bead:  Good for installation of wallboard after installed.

Ø       U Bead: Sometimes called J metal by contractors. Metal is noticeable.

Ø       LK Bead: Trim used for various thicknesses in wallboard.  Kerfed Jamb.

Recycling: Old wallboard can be used in soil additive.

Glass Reinforced Gypsum:

Ø       Gypsum product with fiberglass mixed into the mix.

Ø       It can conform to almost any space.

Ø       Use in an interior space where it is NOT exposed to dampness.

Georgia-Pacific – Picture of GRG Product.

LATH AND PLASTER:

Ø       Stucco is an exterior form of plaster. (Portland Cement)

Ø       Plaster is made of Cementing compound, fine aggregate, and water.

Ø       Lath is slats of wood Sized 2” x 4’

Ø       The method of a Lath Plaster Partition is to have 2x4 or 2x6 studs 16” OC. Tack the 2” x 4” Lath to the stud. The 4” length is meant to cover three studs. Apply vertical (temporary) Latchs across the horizontal Laths. Apply plaster over the entire surface. Remove the temporary slats. And cover those areas with plaster. Make sure the plaster is pushed through the cracks in the Laths.

Ø       There is a second layer of plaster applied. This is Thick and sandy about ½” thick.  Smooth White finish coat goes on last.

  

Picture from Wikipedia – Lath and Plaster