Skip to content

Customer Support: 773-636-4512

How to waterproof a bathroom

How to waterproof a bathroom

Mold and mildew grow wherever there is excessive humidity and they thrive in grout and shower walls. The best solution is adding a shower waterproofing system. This article will discuss bathroom waterproofing and shower membranes.

Shower waterproofing: a real issue

The shower protects wood structures in the house by collecting water and directing it to the plumbing system. Unfortunately, old substrate systems cannot safeguard grout and shower walls. Grout comprises cement and fine sand bound together. It is effective at holding tiles in place, but it is water-permeable, which allows water to penetrate the waterproof substrate, an underlying layer, or substance.

When there is no protective layer, the substrate underneath the cement absorbs water and damages whatever lies below the shower. This includes drywall, 2×4 posts and plywood. In theory, the water should dry between showers, but if the shower is used regularly, this will not happen.

Solutions to waterproof a bathroom

So, which waterproofing system should be used? When choosing a waterproofing system, consider factors such as shower maintenance, structural integrity and humidity damage. Also, waterproof the bathroom floor before tiling helps to protect the shower from moisture to limit or eliminate mold growth.

If someone is worried about grouting getting wet and wants a bathroom water sealant, the contractor should consider installing a waterproofing membrane. The membrane will direct the water flow toward the drain, preventing mold growth.

What’s the best shower waterproofing solution?

The floor beneath the shower can be protected in several ways. Traditionally, copper and rubber shower pan liners were installed under mortar bases. This system will allow water to penetrate slowly through mortar joints and the pan liner will prevent the subfloor from becoming wet. However, this type of system is susceptible to shifting and resolving, which can affect the incline of the liner. As a result, excess dampness merges, resulting in mold and mildew growth. However, this can be avoided if the contractor seals the floor and gets the best waterproofing for bathrooms.

Because many prefer water-proof membranes, they no longer use copper or rubber pan liners. The modern membranes are made up of a thin layer of water-tight material that lies beneath the tile layer to prevent water from penetrating the mortar subfloor. The frying pan liner preserves the subfloor below by collecting excess moisture.

There are four main types of water-proofing membranes available today. There are liquid membranes, sheet membranes, foam shower bases and foam wallboards.

Fluid Membranes

Fluid membranes can take any size or shape you prefer. They also have strength, weathering resistance, and elasticity to fill the cracks underneath the surface. Fluid membranes are essentially water-proof paint applied via rollers. When the membrane dries out, it becomes an elastomeric layer that remains flexible. An example of this kind of membrane is the Mapelastic AquaDefense from MAPEI.

Sheet Membranes

Sheet membranes are popular due to their ability to withstand high-pressure water. They are a blend of plastic attached to the backer board of the shower surface and the floor tile. Most sheet membrane layers are peel-and-stick. Because of their durability and ease of installation, they are one of the best options. Together with the options from SCHLUTER, contractors are now using the innovative waterproofing solutions from GURU, a well-known European brand, closely linked to the best tile manufacturers in Europe.

Preslope Shower Pan

A Preslope shower pan is typically sold with shower foam that is water-proofed, just like the tray. There may also be a waterproofing membrane bonded to the tray as well as shower drains and accessories. These packages often contain foam similar to the foam wall surfaces.


The best water-proofing system for a shower floor will generally depend on the budget and the remodel being done. Showers can be waterproofed quickly, easily and economically with waterproof membranes. However, if you want to have professional advice before deciding what to use, call or visit The Tool Locker where you find a wide range of waterproofing solutions and floor and tiling tools.

Previous article Concrete Tools Every Contractor Should Have
Next article How to cut tile without a wet saw

Leave a comment

Comments must be approved before appearing

* Required fields

Newsletter Subscription

Get the latest deals and updates from The Tool Locker

Net Orders Checkout

Item Price Qty Total
Subtotal $0.00 USD

Shipping Address

Shipping Methods