Residential

Residential Exterior | Residential Interior

Residential Exterior

SBPCA Implements Plastering Industry Standards
The Santa Clara Valley is in Earthquake territory and has changed the construction guidelines over the years. Many of these changes have been in wall construction. Today it is not uncommon to see the exterior framed walls covered with plywood or OSB Board. And when the walls are not covered with plywood there is a product that has been used for over 27 years - Paperbacked Lath. Paperbacked Lath has a line wire running through the paper and woven wire. The line wire is not 18GA it is only 20GA. The line wire works the same as 40 years ago.

The SBPCA has experienced the changes and continues to adapt new standards and techniques that meet the local and federal codes. The Plastering Industry sets standards for construction. SBPCA implements the industry standards even though codes change from city to city.

SBPCA product recommendations

60 minute grade 'D' paper, two layers over sheeting
60-minute paperbacked lath at open stud framing
17GA 1 ½" woven wire self furred fastened with staples
Staple must have a 1" penetration into the stud
Galvanized trims, weep screed, casing, control joints, reveals, and corners aids
Portland cement is commonly used in the South Bay Area
Mix ratio 1 plastic to 1 common with clean sand
Finish, premixed by manufacture

Plastering Industry Methods of the Past
The SBPCA has seen many changes in the Plastering Industry over the past 34 years. The wall of the past had more of the normal home stress assumed by the plaster construction. Rather than stress walls and plywood sheeting, the plaster construction was designed to add significant stability to the structure. The plastering construction of the past included:

The lather would run Line wire (18GA wire) up the outside of the wood stud all around the exterior of the house.
Both the building paper and the 1" 20GA woven wire would be nailed to the stud.
The nails would have a spacer to hold the wire away from the wall to assure a good key on the first coat (Scratch Coat). The Nail was called a Dawg's in the trades, and a furring nail to everyone else.
The Line wire would support the paper when the plaster would apply the Scratch coat (first coat).
The brown coat is the second coat and leveling Coat 3/8". Finish coat thickness varies from 1/16" to 3/16".
The finish texture is what would lead to a 3/16 depth. Example: (Dash Texture, machine applied)

Stories have been told of lather's pulling down a house while pulling the Line wire. Literally twisting the corners of the wood stud framing, collapsing the corner of the structure. The Lather's today only read about this system.