Waterproofing your home

Check your gutters regularly to make sure they are not leaking or blocked. Photo by David Stanley Mukooza

What you need to know:

  • Silicate-based concrete sealer, which reacts with the ingredients in brick work and concrete to form a waterproofing coating; this sealer can only be used on unpainted walls.
  • Francis Munyambabazi, a structural engineer, says a homeowner can choose concrete waterproofing coating, which is a cement-like product that adheres to concrete and brick or sand work permanently; it can be applied to any surface, including painted walls.

In house construction and building, waterproofing is a fundamental aspect of creating a building that will be tolerant to rainy weather conditions.
According to Moses Kinobe, an architect at Kinobe and partners, water damage does not only ruin the structure of the house thereby affecting its sale value, but can also damage your personal property and valuable possessions. It damages the paint work and finishing in your home.
There are different areas of your home where it is vital to keep water at bay, and in each of those areas there are various methods of waterproofing.

Basement
If you are starting on a building project, waterproofing your basement is the most important decision you must make for your entire house. This will prevent water from entering the basement of a house.
Hydrostatic pressure can cause damage to the foundation and the walls.
The pressure forces water through cracks in the foundation, through openings caused by expansion and contraction that lead to floor cracks. This in the long run causes mold, decay and other moisture related problems to your house.

Kinobe says, “Waterproofing is needed anytime a structure is built at ground level or below ground. Waterproofing and drainage considerations are very important in cases where ground water is likely to build up in the soil.”
This higher the water build-up in the soil, the higher the pressure exerted underneath basement floors and against basement walls.

Foundation
The foundation is what the house is built on and what keeps the building where it was built. The commonest foundation problem is water because wet soil beneath a foundation can make it lose strength. Typical concrete is not waterproof and although it will keep out liquid water, water vapour can still penetrate quite easily. Keeping water away from concrete foundations and preventing it from moving through the concrete are essential.
Accomplishing your goal of draining any water away and ensuring a dry interior space below grade can be relatively simple or fairly involved.

Francis Munyambabazi, a structural engineer says: “Depending on geographic location, climate, topography, water table conditions and depth of the foundation, your foundation can be waterproofed by using drains to move water away from the bottom of the foundation, wall treatment to prevent moisture from moving through the wall and ground surface treatment adjacent to the building to direct surface water away.”
On the inside of the foundation, install about six inches of crushed stone and drainage pipes that run to the sump pail to take any water that makes its way under the foundation. Then install a vapour barrier of plastic on top of the crushed stone and then the concrete basement floor.

Roof protection
When it comes to waterproofing, Francis Munyambabazi, a structural engineer, says it is also important to ensure that your roof is offering you and your home the utmost protection against water damage. Flat roofs are particularly susceptible to damage once they are not well proofed from water.
The huge financial cost involved in replacing an entire roof means that most people usually go for a simple patch-up job if a problem occurs but it is important that you consult your architect to get the problem fixed.

You need to inspect your roof every year for any missing, lose, blown away or cracked tiles, shingles or iron sheets and have them repaired immediately.
“Ensure that the roofing shingles or tiles are in place and are securely fastened and sealed to the roof especially at the roof edge as this is often where rain and wind can do the most damage,” Munyambabazi warns.

Brickwork
It is important to proof the brickwork of your house which will prevent water or moisture getting into your home. The easiest way to seal your brickwork is to repaint the outside brickwork of your house using a specialised outdoor paint, which are more hardy and weatherproof than regular paint.
Munyambabazi says: “Waterproofing paint also delivers a good waterproofing performance but ensure that you choose a breathable formulation that is especially designed to allow walls to breathe and eliminate moisture. The product can be applied to surfaces previously painted.”

Gutters
Kinobe says: “It is important to note that waterproofing your house is easily done with well-maintained gutters. Many times gutters become clogged with leaves and other debris.
“These cause rain water to build up when it rains and the water overflows from the gutter, damaging bricks and mortar on the walls. It also seeps through the bricks causing damage to your household furnishings and paintwork.”

The build-up of leaves and rubbish in a gutter provide a breeding place for windblown seeds to lay root. The weeds will then start to grow naturally in your gutter thereby leading to a blockage.
Kinobe recommends that you clear the gutters from all wet leaves and debris using a trowel or a scraper at least every year.
Gutters are susceptible to cracks, buckling and leaks. It is important also that you inspect the various joints and brackets of the guttering regularly to make sure they are not leaking.

What to use

Select the right water proofer because there are a series of waterproofing products are available in the market to help homeowners protect their homes from external moisture.
Francis Munyambabazi, a structural engineer, says a homeowner can choose concrete waterproofing coating, which is a cement-like product that adheres to concrete and brick or sand work permanently; it can be applied to any surface, including painted walls.
Silicate-based concrete sealer, which reacts with the ingredients in brick work and concrete to form a waterproofing coating; this sealer can only be used on unpainted walls.

Plastering helps improve appearance, make walls more solid, and protect them against moisture. Although most exterior plasters have waterproofing characteristics, elimination of water infiltration problems can be done by adding a plaster waterproofing additive.