Types of Waterproofing

Types of Waterproofing

Waterproofing a building is the process of applying an impervious barrier over the any or all of its surfaces. This could include the foundation, roof, walls and other structures and prevents water from penetrating through these surfaces. Depending on the method, this could either make the surfaces water-resistant or even waterproof.

The most common materials used in waterproofing are cementitious material, bituminous material, liquid membrane and polyurethane liquid membrane.

Some parts of a building that should be waterproofed include basements, walls, bathrooms, kitchens, balconies, decks and roofs – to name a few.

Types of Waterproofing Methods for Buildings

1. Cementitious Waterproofing

The materials required to apply cementitious waterproofing are readily available at most suppliers of masonry products and is fairly inexpensive. As a result, contractors will commonly use this method. Additionally, they are easy to mix and apply.

You’ll usually find internal wet areas such as toilet floors constructed with the cementitious method. Cement, by its nature, is usually a rigid or semi-flexible material, but since contractors usually apply this method in internal areas such as toilets, they don’t have it exposed to sunlight and weathering. Thus the cementitious method does not go through the contract and expansion process.

Applications of the Cementitious Method

Contractors commonly apply cementitious waterproofing to the following types of structures:

  • Water Treatment Plants
  • Sewage Treatment Plants
  • Bridges
  • Dams
  • Railway & Subway Systems
  • Marine Cargo Ports & Docks
  • River Locks/Channels & Concrete Dykes
  • Parking Structures & Lots
  • Tunnels

2. Liquid Waterproofing Membrane

A liquid membrane is a thin coating which usually consists of a primer and two coats of top coats.
Waller42 [CC BY-SA 3.0], via Wikimedia Commons

A liquid membrane is a thin coating which usually consists of a primer and two coats of top coats. Contractors may apply the membrane by spray, roller, or trowel. Its liquid form means that it offers more flexibility than cementitious types of waterproofing.

When the liquid dries, it cures into a rubbery coating on the surface. The elongation properties of the coating can reach as high as 280%. The durability of the waterproofing coating depends on the type of polymer the manufacturer used when making the liquid membrane.

3. Bituminous Coating Waterproofing

Bituminous waterproofing has a flexible protective coat in accordance with its formulation and polymerisation grade. The polymer grade will influence its flexibility and protection against water. Additionally, fibre reinforcements can strengthen the coating.

Some contractors may refer to bituminous coating as asphalt coating. Common applications of bituminous coatings includes areas that are beneath screed wet. It is an excellent protective coating and waterproofing agent, especially on surfaces such as concrete foundations.

Bituminous coating is not suitable for exposure to sunlight. Prolonged exposure to sunlight will cause the coating to become brittle and fragile unless it is modified with a more flexible material such as polyurethane or an acrylic based polymer.

The flexibility of the finished product always depends on the solid content of the polymer added to the bitumen.

4. Bituminous Membrane Waterproofing

Bituminous waterproofing membranes include a torch-on membrane and a self-adhesive membrane
W.carter [CC0], via Wikimedia Commons

Another type of bituminous waterproofing is in the form of a membrane. This method is a popularly used for low-sloped roofs because of their proven performance. Bituminous waterproofing membranes include a torch-on membrane and a self-adhesive membrane.

Self-adhesive compounds comprise of asphalt, polymers and filler. Additionally, certain resins and oils may be added to improve adhesion characteristics. The self-adhesive type has a low shelf-life because the bonding properties of the membrane reduce with time.

Torch-on membranes include exposed and covered types. Exposed membranes often have mineral granular aggregate to withstand the wear and tear of weathering. In covered types of membranes, contractor will apply one protective screed to prevent the membrane from being punctured.

5. Polyurethane Liquid Membrane Waterproofing

Building owners often opt to use a polyurethane liquid membrane on a flat roof area, thus exposing it to weathering. This waterproofing method is more expensive than the previous ones.

A polyurethane liquid membrane can offer higher flexibility. Polyurethane is very sensitive to moisture content present, therefore before application, one has to be very careful evaluating the moisture content of the concrete slab, otherwise peeling or separation of membranes may happen after some time.

Professional Waterproofing and Damp Proofing Services

At AmanziProofing, we provide expert assistance in waterproofing and damp proofing your home or office. Get a free quote today.

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