Apply plumber's putty — Mount the Air Gap
Part of project
How to Install a Dishwasher Air Gap on a Countertop · Step 3 of 7
In this video
Take a small amount of plumber's putty and roll it in your hands into a rope about 1/4' in diameter. Wrap the rope around the underside of the top edge of the drain stopper. Place the stopper in the drain hole and press down while rotating clockwise. The excess plumber's putty should squeeze out around the drain stopper. Use the drain removal tool to make the seal complete and to remove the excess plumber's putty.
Goal: Apply Putty
Used in this video
- Drain removal tool (Tool Type: Pliers, Power Source: Manual, Material Compatibility: Metal, Size/Capacity: Medium, Durability: High, Reusable, Cost: Medium, Tool Accessibility: Specialized tool, Tool Material: Metal, Tool Size/Length: Handheld, Ease of Use: Easy, Effectiveness: Highly effective, Safety Concerns: Low risk, Tool Length: <12 inches, Tool Complexity: Simple) — sealing and tightening drain stopper
71K subscribers
FAQs
Is a dishwasher air gap really necessary, or can I skip it to avoid drilling a hole in my countertop?
An air gap is a crucial plumbing safety device designed to prevent contaminated water from siphoning back into your clean dishwasher, especially if the drain clogs. While some local codes allow for a "high loop" drain hose as an alternative, many jurisdictions, like California, still require a physical air gap. Always check your local plumbing codes to ensure compliance and maintain proper sanitation.
Drilling a hole in my countertop sounds intimidating. What type of drill and hole saw do I need, and how can I ensure a clean cut?
For a clean hole, you'll need a powerful drill like the Makita 7 Amp 1/2 in. 900 RPM Drill and a bi-metal hole saw from a kit like the Milwaukee Hole Dozer set, sized correctly for your air gap (typically 1-1/4 to 1-1/2 inches). Start with a pilot hole, use steady pressure, and drill slowly, especially for harder materials like granite or quartz, to prevent chipping. Placing painter's tape on the countertop can also help prevent surface damage.
What are the most common mistakes people make when installing an air gap, especially concerning leaks?
The most common mistakes involve improperly connecting the hoses and not securing them tightly. Ensure all hose connections are seated firmly and secured with stainless steel hose clamps, like the Everbilt 5/16 - 5/8 in. Stainless Steel Hose Clamp. Additionally, apply a small ring of plumber's putty, like Oatey 14 oz. Plumber's Putty, under the air gap's top flange before tightening it down to create a watertight seal against the countertop.
My kitchen design doesn't really allow for an air gap on the countertop. Are there any alternative methods to prevent dishwasher backflow?
Yes, in some areas, a "high loop" installation is an acceptable alternative to a countertop air gap. This involves securing the dishwasher drain hose in a high arch under the sink, ensuring it rises above the flood level of the sink or disposal connection. However, local plumbing codes vary, so it's essential to verify if this method is permitted in your area before skipping the air gap.
Apply plumber's putty — Mount the Air Gap
Part of project
How to Install a Dishwasher Air Gap on a Countertop · Step 3 of 7
In this video
Take a small amount of plumber's putty and roll it in your hands into a rope about 1/4' in diameter. Wrap the rope around the underside of the top edge of the drain stopper. Place the stopper in the drain hole and press down while rotating clockwise. The excess plumber's putty should squeeze out around the drain stopper. Use the drain removal tool to make the seal complete and to remove the excess plumber's putty.
Goal: Apply Putty
Used in this video
- Drain removal tool (Tool Type: Pliers, Power Source: Manual, Material Compatibility: Metal, Size/Capacity: Medium, Durability: High, Reusable, Cost: Medium, Tool Accessibility: Specialized tool, Tool Material: Metal, Tool Size/Length: Handheld, Ease of Use: Easy, Effectiveness: Highly effective, Safety Concerns: Low risk, Tool Length: <12 inches, Tool Complexity: Simple) — sealing and tightening drain stopper
Frequently Asked Questions
Is a dishwasher air gap really necessary, or can I skip it to avoid drilling a hole in my countertop?
An air gap is a crucial plumbing safety device designed to prevent contaminated water from siphoning back into your clean dishwasher, especially if the drain clogs. While some local codes allow for a "high loop" drain hose as an alternative, many jurisdictions, like California, still require a physical air gap. Always check your local plumbing codes to ensure compliance and maintain proper sanitation.
Drilling a hole in my countertop sounds intimidating. What type of drill and hole saw do I need, and how can I ensure a clean cut?
For a clean hole, you'll need a powerful drill like the Makita 7 Amp 1/2 in. 900 RPM Drill and a bi-metal hole saw from a kit like the Milwaukee Hole Dozer set, sized correctly for your air gap (typically 1-1/4 to 1-1/2 inches). Start with a pilot hole, use steady pressure, and drill slowly, especially for harder materials like granite or quartz, to prevent chipping. Placing painter's tape on the countertop can also help prevent surface damage.
What are the most common mistakes people make when installing an air gap, especially concerning leaks?
The most common mistakes involve improperly connecting the hoses and not securing them tightly. Ensure all hose connections are seated firmly and secured with stainless steel hose clamps, like the Everbilt 5/16 - 5/8 in. Stainless Steel Hose Clamp. Additionally, apply a small ring of plumber's putty, like Oatey 14 oz. Plumber's Putty, under the air gap's top flange before tightening it down to create a watertight seal against the countertop.
My kitchen design doesn't really allow for an air gap on the countertop. Are there any alternative methods to prevent dishwasher backflow?
Yes, in some areas, a "high loop" installation is an acceptable alternative to a countertop air gap. This involves securing the dishwasher drain hose in a high arch under the sink, ensuring it rises above the flood level of the sink or disposal connection. However, local plumbing codes vary, so it's essential to verify if this method is permitted in your area before skipping the air gap.