The next step after the thinset is dried on the walls of the shower will be the application of RedGard waterproofing membrane. This waterproof coating will be the final protection from any water that could seep through the grout of the tile. Since sealing tile grout can only do so much, waterproofing your backer board is essential.
The application of RedGard is very simple as long as you keep a couple things in mind. Besides the toxic smell of something that resembles an old memory of bleaching hair, it’s the application process that becomes the challenge of whether or not this will go smoothly and quickly. The consistency of the RedGard is like pudding and will be like applying putting to your walls. being said, you can imaging how messy this process can be if you are not careful with the amount that you apply on the wall at one time. The trick I found that worked well is to use a 4 or 5 inch paint brush and paint the RedGard on the walls then follow up with a 3 or 4 inch 3/8 nap roller to even out the coat.
Once the RedGard is applied onto all of the walls, it dries pretty quickly so you will need to balance between being as neat as possible and moving quick enough to apply before it dries. Once you have completed all of the surfaces of the backer board, wait about an 2 hours and apply a second coat the same way.
RedGard does color change which makes it really easy to tell when it’s dried. When you apply it onto a wall you will see that it is extremely pink in color. Once it dries is turns dark red (like the image below).
Remember to wear cloves, eye protection and a long sleeve shirt. Once this stuff dries on your skin, it will take days to get off without using chemicals. Also, mask away any surfaces that are in your target zone but won’t be getting the RedGard treatment. I got a little on the window frame and it’s possible that it may be on there for life.
Here are some of the images from today, feel free to ask any questions about the process as it’s was fun yet challenging.