HOME & PROPERTY: How to waterproof your building

How do you waterproof a building? In Tanzania the climate is aggressive especially on the coast. Water and moisture is a constant threat to buildings.

Waterproofing is a complex process, so you will need further technical advice and expertise on your specific project.

Build it right the first time

Waterproofing is often considered after a building has experienced water damage. Rising damp, leaking roofs, hairline cracks on the walls and structural weaknesses are expensive to repair.

Waterproofing must be considered as you plan and design your building. It is most effective during new construction. Ensuring effective waterproofing at this early stage:

1. Will protect your building’s interior from water damage during construction itself

2. Will ensure your building is moisture-sealed, promoting long-term comfort and safety and

3. Will save you money – would you rather invest early in a strong, secure house or pay later for continuous repairs?

Select the right materials, specify effective products and draw up a working guide that considers the project’s waterproofing needs and solutions before construction begins. Remember this rule of thumb: build it right the first time!

Understand the problem

The important thing to remember is that there is a solution to every problem.

One must identify their building’s waterproofing problems, or their site’s potential waterproofing needs, before being able to explore the range of waterproofing solutions to find one suited for their building. For example, if damp is higher than 1 metre above ground level, this is probably not rising damp but a leak. Being able to identify the cause enables you to determine the solution.

Below, we examine the three main waterproofing problem areas, and an overview of their solutions. Each problem has a unique solution.

The 3 main waterproofing problem areas are:

1. The Roof

2. The Wall

3. The Floor

Today, we focus briefly on (1) The Roof:

Ensuring a watertight roof goes a long way to ensuring the interior of your building does not face water damage.

What type of roof is planned? Is it a flat or pitched roof? What materials are used? For example, a concrete roof would have a different solution from a stone-coated metal roof tile like Decra or Fortiza.

Identifying the materials and orientation of the roof. For example, a flat concrete roof is best waterproofed with crystalline waterproofing. Xypex Admix C-1000 NF could be added into the concrete at the time of batching, while Xypex Patch n Plug with Xypex Concentrate could be used to repair existing structures.

A pitched concrete roof might be best waterproofed by bituminous membranes, or repaired with an acrylic coating like Bitumat Synroof.

Each material and orientation has a different waterproofing solution, during either construction or repair.

Waterproofing is an important but delicate process. Understanding its importance and getting in touch with the right technical expertise and experience means you can do it right. The tips above provide a basic understanding of waterproofing.

This article was written by Nabaki Afrika who has over two decades of waterproofing experience.