The best way to soundproof a dishwasher is by using the Super Soundproofing brand of absorbent material in the door of the unit as well as the dishwasher cabinet. The easiest way to achieve security of the soundproofing material is to use glue.
In order to ensure accurate soundproofing, the dishwasher door needs to be removed. Next, the foam material found between the front door and outside panel needs to be removed and replaced with Super Soundproofing absorbent material. After this is done, the entire unit needs to be removed from the counter and covered with the absorbent material. The average dishwasher requires the material to be around 1/2 an inch thick, but may be between 1 to 2 inches thick depending on the size of the unit.
Another way to soundproof a dishwasher is by replacing the original insulation with contact cement in the outer panel, kickplate and tub. The dishwasher dimensions should be measured before the soundproofing material is applied. After the new, soundproof insulation is installed, it is also highly recommended to insert dishwasher baskets for small dishes. This helps prevent smaller dishes from moving around during the wash, which not only saves dishes, but reduces noise.