What is a hot mop?
All tile showers need to have the shower pan waterproofed because water soaks through the tile and grout. Having a properly sloped waterproof barrier is needed between the shower and the structure of the home. The hot mop acts as this barrier. The hot mop can be thought of as a funnel; any water that makes it to the hot mop waterproofing is directed to the "weep" holes at the base of the drain.
How should we tile over the hot mop?
The hot mop shower pan will go up about 10 inches on the walls. The tile backer (hardie backer, cement board, scratch & float, etc) on the walls should be set so that it overlaps the hot mop on the walls and into the hot mopped shower pan. Most tile setters float another layer of concrete/mortar over the hot mop floor and dam before applying the thinset and tile. Please note that it is very important to NOT PUNCTURE THE HOT MOP BELOW DAM LEVEL.
What can I expect in regard to the smell?
Hot mopping is a smoky and smelly process. We try to mitigate the intensity of the smell by using low/no smell asphalts. However, there is a distinct "tar" smell that will be around while we are hot mopping. The duration that the odor lingers is dependent on many variables (weather, ventilation, etc).
Will you cover finished areas?
We carry about 100ft of canvas drop tarps to cover carpeted areas. We do not cover hard surfaces with our tarps because of safety reasons. We recommend that you also ask your contractor to cover any hard surface walkways with the appropriate non slip coverings.
Do I need to water test my shower pan? If so, how?
We recommend doing a water test two hours after the hot mop. This is to allow it to cool. If filled while hot it may deform the asphalt surface. You need to make sure the drain or drain pipe has test plug otherwise the water will go down the drain through the weep holes. If the drain does not have a built in test plug one can be purchased at a local hardware store.
Can you prepare the framing and plumbing for the hot mop of my shower pan?
We do not do any of the framing so that must be complete before we arrive. See our Site Prep page for more details. If needed, we can install a standard drain. However, there needs to be a new 2 inch ABS pipe that is sticking out of the subfloor. There needs to be a 2 inch clearance from the outside edge of the pipe to the subfloor and with no couplings below.
Will you guys waterproof my shower pan using any other method?
We currently only hot mop because we believe that hot mopping still offers the best value and protection.
Are there any drains that I should avoid?
Yes. Some discount home improvement stores sell a gray cast-iron drain that slips-on over the drain pipe and has a rubber grommet that has to be compressed against the pipe. These drains have a hard to access tightening mechanism for the rubber seal that make it vulnerable to leaks around the drain pipe. We have to limit our warranty on our work when these drains are installed. For a reasonable price, we can usually replace these drains with a more secure shower drain set that we carry.
I feel that another trade working in the bathroom may have compromised the integrity of my hot. What should I do?
Start with taking pictures of what you think is the compromise. Then water test the shower pan by plugging the drain pipe and filling with water. If you want the extra peace of mind, you can hire us to come back out and remop over the shower pan with another layer of asphalt.
My drain is not level can you level it for me?
We can work with a gap that is less than three inches on the wall backing. If it is greater, you can nail a tin shingle over the gap. These can be found at you local home improvement usually in the roofing section. Just make sure that the sheet of metal is at least 27 gauge. If it comes in small roll than it is two thin.
Can I use the tile backer (green board, hardie backer, cement board, etc) as the blocking for the hot mop of the shower pan?
We highly discourage using the tile backer as backing for the hot mop. However, if you decide to do this you will NEED to put another layer over the backing that we hot mopped onto. The final backing for the tile has to overlap into the hot mop shower pan so that all moisture is caught by the pan.
How do I protect the weep holes after hot mopping?
Some typical ways to protect the weep holes at the base of the drain is to surround them with gravel, crushed tile, tile spacers, and/or some sort of mesh. You can find pictures and more detailed descriptions on our blog article Keep Your Weep Holes Open.
What else can you guys waterproof using hot mop?
Hot mopping provides good waterproofing on floors that will have tile and be exposed to high amounts of water that has will runoff. Some examples are showers, low slope roofs, decks, planter walls, etc. However, hot mop does not work well for areas that will pool water.
Can you also float the mud/mortar base over the hot mop so we can just set the tile?
Before hot mopping we create a preslope for the shower pan by dry packing mortar mix to create the slope to the subflange of the drain assembly. Once we are done hot mopping, the finished shower pan will have the cured asphalt exposed. Floating the mud base for the tile floor over the hot mop is uniquely part of the tile setting trade. Our hot mopping technicians have only been trained on hot mopping the shower pan and consequently we can not set the mud base for your tile.
We have a leaky pan. Can you just hot mop over the existing tile?
No. We can only hot mop and warranty our work when the site is prepared to as described in our Site Preparation page.