The Step-by-Step Process of Installing a Hot Mop Shower Pan

This blog will give you what a technician will do to give you a top quality hot mopped shower pan. Please see this blog on what needs to be completed prior to you scheduling your appointment, proper preparation is the key to quality and insures that your shower pan has no “weak” areas that could result in a leak that could have been avoided…as in any trade there are those who will just do the work without any concern for what happens after they leave…and will hot mop any pan as is…leaving you with the problem can develop after the fact!

When your tech arrives he will come inside and see where the location of your pan is…taking note of any obstacles that may be in the way. The tech will inspect the area to be hot mopped and if unsatisfactory will call the office and explain what is not correct. The office in turn will notify the contractor of what needs to be done before the hot mop can be done. Note: the office will ask for pictures of your shower pan when you schedule, and can determine if your pan is ready before the tech arrives. This is very helpful and prevents having to be rescheduled and avoiding the cost of a return trip charge if applicable.

The tech will now measure the dimensions to determine the material amounts needed. The tech now preps the area around his kettle to catch and debris, cut and fold all his felt paper. Now he will return with his toolbox and other tools and materials. This is after covering the path with drop cloths and /or rosin paper to the shower pan also taping off and/or covering the areas he needs to protect! Next comes the prepping he needs to do before the hot mop is applied, this can include adding metal to areas that could not be blocked, sweeping and cleaning the floor area, checking the blocking for “shiners” these are loose nails or the heads of nails sticking out too far from the framing. Next the drain flange is removed and mastic is allied in an even layer to the bottom flange; this is done to create a bond of the 1st layer of felt to the bottom flange of the drain to ensure a positive waterproof seal when the top flange is reinstalled and tightened down. Next comes the application of the pre-slope. This is accomplished by the tech spreading a dry mortar bed and troweling to create the proper “slope” for all areas of the shower pan floor to the drain. Once the tech has achieved the desired results it is saturated with water and troweled to “burn in” the water to give the preslope a solid foundation to apply the hot mop process. The hot asphalt is then brought in a welded steel bucket for the process to begin. It starts with a coat of the hot asphalt being applied to the preslope and wallarea in which the hot mopper has determined the starting point, the 1st sheet is carefully laid in the slurry of hot tar making sure that the fold that goes up the wall is tight to the corner, and rolls up smooth onto the wall, foot and body weight pressure is used to push the felt into the hot slurry on the floor to make the preslope mortar, the slurry coat of hot asphalt, and the felt paper bond together to form a waterproof seal and solidadhesion to each other. The upper flap of felt paper is then checked for bond and is pulled down and more hot asphalt is applied in what is called, back mopping, the “flap” is then pushed onto the wall with enough pressure to achieve solid adhesion to the backing. This process is done 2 more times…making a total of 3 slurries of hot asphalt and 3 layers of paper. Before the final top coat slurry is done wall areas are stapled to keep everything in place while the hot mop cures, the drain pipe area is cut out and the top flange “clamping ring” is securely fastened to the bottom flange creating a water tight seal. Fiberglass reinforcement is added to corners and any seams as needed. Now the final coat of hot slurry is added and is acritical part of the process. The proper amount of hot asphalt is needed to get the area covered correctly. Not too much on the walls to leave heavy sags, or too much on the floor to cover the top flange or the drain. This is where the tech really has to work his “mop” to give the shower pan the best top coat they can. Time now for cleaning up! This is where a good installer will have minimal issues! Hot mopping can be a messy job but those with experience know how to prep the area before starting!How to keep the area sanitary while working and be considerant of the customers’ home! Final notes, a minimum of 3 hours is needed for the hot mop to cure before a water test can be performed, and the weep holes must be cleaned out by the contractor or others! All in all an average shower which is a 3×5 area with or without a bench will take on the average 1-½ to 2 hours from start to finish…one if not the best turn around time in the industry.