Waterproofing bid estimation — AI calculates surface areas for you

Waterproofing bid estimation is based on the area to be waterproofed, calculated separately for floors and walls. In wet rooms, wall waterproofing does not run the full height but by zones: typically up to 6 ft at the shower and 4 ft elsewhere, so using the full wall area overstates the quantity. The floor is waterproofed completely and turned up onto the walls by a set height. Accurate area is critical because waterproofing is applied continuously — too little material means re-doing it, too much is wasted cost.

Most of the waterproofing labor comes from details, not flat surface. The drain connection, pipe penetrations, the wall-to-floor transition and the corners all require reinforcing fabric and an extra membrane layer, and they are priced per piece or per linear foot. A single wet room can contain several penetrations and tens of linear feet of transitions, so details must be calculated as their own items, not hidden in the square-foot price.

Wet-room waterproofing should use a listed, tested system in which the membrane, reinforcing fabric, penetration pieces and the drain collar all belong to the same approved assembly (ICC-ES listed / ANSI A118.10 compliant) — parts from different manufacturers should not be mixed. This ties the material choice and affects the price: a liquid-applied membrane is cheaper ($5–8/sqft) than a sheet membrane ($8–12/sqft). Waterproofing is also part of moisture control, so the bid often includes inspection and documentation before tiling.

Massoi calculates the floor and wall areas to be waterproofed from the floor plans automatically, accounts for the height zones (6 ft / 4 ft) and breaks out the linear feet of penetrations and transitions. With the areas and details ready, the contractor can choose the system and price material, labor and details separately — without doing zone takeoff by hand.