What is ASTM C840?

What is ASTM C840?

ASTM C840-08 or GA-216-2013 provides the following requirements for installing control joints in gypsum board. assemblies: Section 20.2 (GA & GA 4.7.2) – Control joints shall be installed where indicated on the plans. Full. height door frames shall be considered equivalent to a control joint.

How often do you need control joints in drywall?

Ceilings: in long expanses of ceilings at 30-foot intervals, with the drywall expansion joint extending the full width of the ceiling, from partition wall to partition wall. Technically, according to expert sources like National Gypsum, drywall movement control joints are recommended at intervals of 30 feet.

How far apart control joints drywall?

30 feet

The maximum recommended control joint spacing for walls and ceilings without perimeter relief is 30 feet. With perimeter relief the maximum recommended control joint spacing is 50 feet.

What is perimeter relief for gypsum board?

The intent of perimeter relief is to make the ceiling independent from the walls that form the ceiling’s perimeter. This allows the ceiling to freely move, thereby reducing the potential for stresses to build within the gypsum ceiling membrane, which leads to cracking.

What is a level 4 gypsum board finish?

A level 4 finish is used where flat paints and lightweight wall coverings will be applied over the wall surface. It is the most common type of finish and is considered the typical drywall level of finish.

What is a level 5 gypsum board finish?

A Level 5 finish is a premium finish, and the highest degree of quality in drywall. It requires all aspects of a Level 4 finish and an additional skim coat of joint compound to cover the entire surface. A Level 5 finish provides a uniformly smooth surface that is obvious in the most severe lighting conditions.

Is it too late to cut control joints?

Joints should be sawed as soon as the concrete can withstand the energy of sawing without raveling or dislodging aggregate particles. For most concrete work, cutting should take place within the first 6 to 18 hours and never beyond 24 hours.

Where do you put drywall control joints?

A: Control joints shall be installed where a wall or partition runs in an uninterrupted straight plane exceeding 30 linear feet (50 linear feet on center for ceilings with perimeter relief).

What is the difference between expansion joint and control joint?

In building materials, a control joint is used to control cracking while an expansion joint is designed to handle structural movement.

What is ASTM C754?

The industry standard for the installation of non-structural steel framing members is ASTM C754: Standard Specification for Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products, which covers all members made in conformance with C645.

What is ASTM c1396?

1.1. 4 Water-resistant gypsum backing board, designed primarily to be used as a base for the application of ceramic or plastic tile on walls or ceilings. This product is also suitable for decoration.

What is the most common finish level for gypsum board?

level 4 finish
A level 4 finish is used where flat paints and lightweight wall coverings will be applied over the wall surface. It is the most common type of finish and is considered the typical drywall level of finish.

What is the difference between level 4 and level 5 drywall finish?

How deep should control joints be?

Contraction/control joints must be established to a depth of ¼ the slab thickness (Figure 2). Proper joint spacing and depth are essential to effective control of random cracking.

How far apart should control joints be?

Space joints (in feet) no more than 2-3 times the slab thickness (in inches). A 4″ slab should have joints 8-12 feet apart. When arranging joints, skilled contractors will often use them to create an attractive diamond pattern.

Are control joints necessary?

There is a reason control joints are considered essential for whatever projects you have in design. Thermal expansion and contraction will occur in buildings – that’s a given – and control joints help prevent resulting cracks and damage.

What is ASTM C1002?

ASTM C1002 — Standard Specification for Steel Self-Piercing Tapping Screws for the Application of Gypsum Panel Products or Metal Plaster Bases to Wood Studs or Steel Studs.

What is ASTM C36?

ASTM C36. August 24, 1990. STANDARD SPECIFICATION FOR GYPSUM WALLBOARD. This specification covers gypsum wallboard, that is designed to be used for walls, ceilings, or partitions and affords a surface suitable to receive decoration.

What is ASTM c1178?

ASTM Standards
This specification covers coated glass mat water-resistant gypsum backing panel designed for use on ceilings and walls in bath and shower areas as a base for the application of ceramic or plastic tile.

What is a Level 5 gypsum board finish?

Does drywall need Level 5 finish?

What does Level 5 Drywall mean? – YouTube

Should control joints be filled?

But if left unsealed or unfilled, control joints can become areas for dirt, dust, and debris to collect and cause problems. In food processing, pharmaceutical, and medical facilities, they can become even greater problem areas harboring water, moisture, and threatening bacteria if not properly filled and maintained.

What is the difference between a control joint and a construction joint?

Control joints focus the cracking so that it’s not ugly or dangerous. Construction joints are interruptions in the slab between different pours of concrete. Since you can’t pour concrete non-stop, there is a break between sections of the pour. Each time you stop the pour, you get a construction joint.

How can you determine location of control joints?

Where To Locate Control Joints in Concrete – Construction Math

Does all drywall have asbestos in it?

Until the late 1970s, almost all American drywall sheets, tapes, and joint compound mixes had asbestos additives. When asbestos-laden drywall is dried and sealed with paint, it’s virtually harmless because it doesn’t emit loose airborne fibers.

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