5 methods of roof and bathroom waterproofing

Water damage possibly caused by a leaking roof or water tank.

Imagine a rainy day when you notice a dripping sound hitting the inside of your plaster ceiling. Over time, the walls and ceiling start to turn brown and the paint starts to bubble. That’s what happens when your home waterproofing has broken down.

Waterproofing prevents water from seeping into the surfaces of your home and causing major problems like mould growth and damage to your property.

How to tell if waterproofing is needed

The most obvious sign is when your ceiling starts dripping during a rainstorm. After a while, there will be a musty odour and mouldy or brown coloured patches on the walls or the floor where the leakage is occurring.

Here are the five most common methods of waterproofing your roof and floor:

1. Cementitious waterproofing

This technique uses cement to create a solid water-resistant layer. The cement is mixed with an acrylic additive to create a sturdier, durable base, then applied as a thick layer and left to dry and harden.

It doesn’t expand or contract under heat exposure. This technique is usually applied in household internals, waterproofing your bathroom before the tiles are laid.

Application of cement to create a sealing layer.

2. Elastomeric waterproofing coating

In elastomeric waterproofing, a special rubbery liquid is used. After applying a coat or two, it cures into a thin rubber waterproof membrane.

Unlike cement, this layer is stretchable. This is important when used as outdoor waterproofing, as it can elongate up to 280% in harsh sunlight.

The liquid can be rolled, troweled or sprayed on. This method is most suitable for roof waterproofing.

Workers rolling on the emulsion onto the surface that forms a membrane layer.

3. Bituminous waterproofing coating

Bitumen is used to pave roads, but, it is also used for waterproofing. Also known as asphalt, it’s flexible due to the polymer grade and fibre reinforcements.

This black liquid is usually applied like paint, spread onto the surface. Due to it containing bitumen-based substances, it isn’t suitable for sunlight exposure as it turns brittle under heat.

So, if used on a rooftop, it needs to be covered by another protective layer such as cement.

Emulsion coating can be rolled on due to its paint-like texture.

4. Bituminous waterproofing membrane

This form of waterproofing comes in a sheet and is rolled out onto the surface. It’s most suitable for low-sloped roofing due to its effectiveness.

Membrane waterproofing comes in two types; torch-on and self-adhesive.

Torch-on membranes are applied with a blow torch and burned as they are being rolled out, whereas self-adhesive ones stick onto the surface.

However, self-adhesive ones tend to have a shorter lifespan as they wear out over time.

Torch-on membrane being burned to the surface

5. Polyurethane liquid membrane

The last method is also the most expensive, and is used mainly on flat roofs. It’s the simplest form of liquid waterproofing and is able to withstand the exposure of elements thus deeming it both an exposed and non-exposed system.

It is also highly malleable meaning it can stretch without giving way. However, polyurethane is sensitive to moisture content. The surface of the structure must be thoroughly evaluated before applying to ensure it doesn’t cause damage in the long run.

Overall, it provides a sleek finish and is rather durable by regular standards.

Polyurethane waterproofing comes in white and it rather versatile

How much does it cost to waterproof your roof or floor?

The cost of waterproofing is not limited to the cost of the materials alone. Professional waterproofing contractors will need to do a detailed inspection to see if there needs to be any preparation work.

Some surfaces may require cleaning before applying the waterproofing, or, if the surface is uneven, it may need hacking to level it.

For a typical terrace house in Malaysia, preparation may range between RM500 to RM2, 000 depending on the condition. The final price will depend on the waterproofing material used.

One of the surface preparations steps is high-pressure water cleaning

Can you do waterproofing on your own?

If the source of the leak is easy to detect, then it’s possible to DIY your waterproofing. For example, when the leak is coming from a worn-out window seal.

But, when the roof is leaking into your ceiling, it can be extremely difficult to detect the source of the leak. You may need to climb up your roof or into your attic to investigate.

In this case, repairing the leak can be a complex task that requires expert assessment and careful execution to prevent the problem from escalating.

How long does waterproofing last?

Waterproofing tends to last from five to 10 years on average. Cementitious, elastomeric liquid emulsion and bituminous coating can last for about five years.

Bituminous membrane and polyurethane can last up to 10 years, depending on factors such as the weather, usage and so on.

How to choose the best waterproofing contractors in Malaysia

To find a suitable contractor to diagnose the problem and provide a quote for the work, you can use Recommend.my to request for waterproofing contractors.

They will arrange for a site visit and provide a detailed quote. The contractor will then suggest the best method to solve your problem according to your budget.

This article originally appeared on Recommend.my – Malaysia’s #1 Home Improvement Services Platform. Recommend.my offers a safer and more convenient way to hire the best home improvement and home maintenance professionals. From flooring to interior design to air-conditioner servicing, get access to thousands of the best local contractors and professionals at your fingertips.