Drainage

Poor Drainage

Poor drainage is one of the major factors causing damp and though our vast experience and plumbing background we are the Guru's in drainage.

We can provide you with a total solution to your drainage requirements:-

• Fin drain
• Soak ways
• Storm water drains
• Surface drainage
• French drains

Is your neighbour's groundwater flooding your yard?

Our drainage experience makes us shine out above the rest. Call Damp Guru for a free consultation.

We provide versatile, site-specific drainage solutions that can be designed especially for your project.

Damp garages, basements etc… Aren't just unpleasant; they can be literally hazardous to your health. On the other hand, a properly waterproofed basement area can be an extra room space for anything from that mother in law to an office or hobby room / man cave.

Good waterproofing is one part of the solution, but by itself is inadequate. The true key to having a dry, enjoyable living space is proper drainage.

This is much more than a simple DIY membrane, but involves the eaves, gutters, and downspouts, and extends to landscaping, sprinklers, and even the slope of the ground around the foundation.

Fin Drain / Curtain Drainage

Fin Drains function as a below ground drainage layer for the collection and transportation of ground water. They consist of a synthetic polymer core surrounded by a geotextile filter which eliminates blockages of the system and enhances filtration. Gone are the days of a simple soak way allowing an area to saturate fully before any drainage can be effective. This new system literally draws a line in the sand and re-diverts any ground water.

The permeable surface area of the products we use rapidly drain water from the soil into the drainage system.

Fin Drains provide an excellent long term performance at a greatly reduced cost, due to flexibility and ease of installation. Some examples of areas where drainage should be installed:-

• Retaining Wall/Abutment Drainage
• Basement Waterproofing
• Wet foundations

(The picture below shows how we repaired a project at the Nelson Mandela school of Medicine.)

Gutters

While groundwater is one obvious cause of wet below ground level areas (basements), it's actually surface water that causes most of the problems. Proper control and drainage of both sources is essential to the success of any waterproofing system.

"Many people are amazed when they learn just how much water can run off their roof," says Grant Dakers. "25mm of rain falling onto a small RDP town house of about 93 m2 of roof translates into more than 2,271.25 Litres of water."

The first line of defence in keeping your basement dry is fastened to the eaves of your house. If rainwater is allowed to just run off the roof, moisture will typically build up around the outside of the foundation and that moisture will make its way through the "solid" walls. Even worse, it can put so much pressure on the foundation that cracks and even major structural damage can appear.

Make sure that rain gutters are clean and free from debris! Downpipes should guide the water well away from the foundation; six meters is good practice.

Ground Level

When builders backfill around a new basement, the soil is not as compacted as the unexcavated soil nearby. Over time that soil slowly settles so that it's not uncommon to find the ground actually sloping towards the foundation rather than away from it.

That's one reason to make sure rain gutters are working, and that downpipes discharge the water well away from the house. Make sure the soil adjacent to the foundation slopes away for a distance of at least three to five meters.

It doesn't have to be much; one to one-and-a-half inches per foot is sufficient to keep rainfall from soaking in close to the walls. Adding extra soil around the foundation to create the proper slope is relatively easy, and can solve many moisture problems.

Flower beds, bushes and shrubs are often planted close to the foundation to shield it from view, but they can cause problems. Be careful not to overwater, and make sure water from sprinklers doesn't touch the walls.Many landscape designs place walkways and other solid surfaces next to the home to ensure the water doesn't soak in close to the foundation.

Surface drainage is the single most important application of foundation waterproofing in our opinion. Unless you have an underground spring or an unusually high water table, the surface drainage portion of your waterproofing system controls the greatest amount of water.

Concrete Protection

Once the water is in the ground, it is kept from the foundation through a system of drainage curtains and subsoil drainage and obviously positive tanking.

A proper below ground level waterproofing design must include a system for collecting, draining, and discharging groundwater away from the structure.

The water collected by footing drains needs to be taken away from the structure. If you're building on sloped land, the footing drains can "run to daylight." If the lot is flat, you'll need a sump pump, which moves the water to either to a French drain placed well away from the house or into a storm water drainage system.

Disposal of Storm Water

This is a very controversial topic taken for granted most of the time as it's ideally at the stage of completion of a project and the developer wants to move on and the client has had enough building.

Sadly it's more important than what meets the eye. In today's times we all trying to do the right thing, so to speak, so we have two options for you as we don't like wasting water at Damp Guru:-

• Free flow catchment harvesting of your rainwater and storing it in external JoJo tanks or the like.
• Underground storage where we submerge modified tanks that diverts all water run-off to these tanks. This then gets pumped and can be reused.

Rainwater Harvesting

Rainwater tanks, traditionally an icon of the rural areas and farms, are becoming a more common feature in urban communities; more and more households are installing a tank on their property.

Why use rainwater?

• Using rainwater can reduce your water bills as rainwater is free.
• Collecting rainwater allows you to be prepared for times of low rainfall, so you can still maintain your garden, especially if there are water restrictions in your area.
• Capturing rainwater reduces the load on storm water systems because roof run-off is not flushed into the drains.
• Using rainwater reduces the need to build more water storage dams, which may have to be situated in environmentally sensitive areas.
• Requires a relatively simple system which is easy to use.
• During the summer season, when the garden doesn't need any extra watering, rainwater can be connected to the house and used for toilet flushing as well as in the laundry.
• Rainwater is also suitable for use in pools and for washing cars.
• In some rural areas, it is possible to use rainwater for all domestic uses, and not draw upon the mains supply.

When should I install my tank?

The best time to install a rainwater tank is when you don't need it. Fitting your tank at the beginning of your wet season will ensure that you have as much water as possible to sustain you during the dry season.

How should I maintain my tank?

Remember that 'prevention is better than the cure', so keep your gutters free from debris with a range of devices or just by cleaning them out regularly. The tank itself needs regular external inspections for leaks and an internal inspection for sludge every few years. This can be dangerous so contact Damp Guru if you need help doing this.

Plumbing and Preparation

• There are a number of factors to consider when it comes to plumbing and preparation before installing your rainwater tanks.
• We will be able to give you some great advice about water tanks, such as the best location and size. You will also be able to get an idea of how much the entire project will cost.
• It is important to ensure that your tank's overflow is securely connected to the storm water system.

Gutters and Roofing

The guttering on your roof catches the water for your tank and needs to be regularly cleared of any leaves or debris. Damaged guttering should also be repaired.

On some houses, the guttering may need to be adjusted to direct the water to the corner of your house where the tank will be installed. Try to make all pipes 'dry'. This means having a continuous downward path so water can't accumulate between flushes.

Lead-based paint and flashing or tar-based coatings found on some roofs affect water quality. Make sure your roof material is non-toxic.

Foundations

The ground where a tank is going to be located needs to be levelled. Larger tanks will also require either sand or concrete foundations. The tank manufacturer's instructions will guide you, but a plumber should also be consulted when deciding where to put your tank to maximise the catchment area.

Pumps

Most rainwater tank systems will require a pump to generate adequate pressure. Washing machines and some irrigation systems require a level of pressure similar to mains water. When connecting your rainwater supply to your toilet or laundry, leading plumbers recommend a pump which will automatically switch to mains supply when your tank water runs dry. In times of water restrictions you must ensure you are not using mains supply on your garden. You also need to provide electricity to the pump close to the tank. Be mindful of neighbours as pumps can be quite loud. Consider choosing a pump with nylon blades as they are quieter than ones with metal blades.

First Flush Diverters

These devices are useful to divert the first 20 litres of rainfall from entering your tank. This will prevent pollutants on your roof from entering the tank. For example, many roofs have lead flashing which can be dangerous. A sump box between the downpipe and the tank can slow the water flow down, separating out any sediment not previously diverted.

Non-Return Valves

Regulations stipulate that backflow devices must be installed to prevent tank water from entering the mains system. Most households have non-return valves installed at the water meter. Some pumps also act as a backflow prevention so extra valves are not required.

Mosquito Proofing

A rainwater tank can be an attractive refuge for insects and other creatures. They are especially enticing as a breeding ground for mosquitoes. There are a range of products you can install on your downpipes and overflows to prevent insects from getting into your water, including mosquito proof mesh.

Leaf-Shedding Gutter Protection

Leaves and debris often build up in gutters. This can affect water flow during heavy downpours and can potentially contaminate your water supply. Avoid U-shaped gutters as they trap leaves and twigs. Gutter protectors, filters and regular maintenance can help to solve this problem.

Top Up Systems

Top up systems use a float valve to measure how much water you have in your tank, much like the ones in a basic toilet system. When the water level gets too low, mains water will turn on and run into the tank to top it up. This can be manually or automatically controlled that we will install within the system.

Issues Associated with Rainwater Use

There are some important factors that can affect the quality of rainwater stored in tanks. These include:

• Contamination from pollutants found in roof and pipe materials.
• Contamination from bird droppings, local pollution, and organic material collected on the roof.
• Breeding of mosquitos in the water supply.

The quality of water you need to maintain will depend on its use. However, water from rooftops that contain harmful chemicals should not be used for any purpose. Drinking water must meet the standards set by health authorities.

These quality issues can be overcome through the use of approved products and techniques. Tanks and other equipment must meet the required standards, and state health authorities will approve most reputable manufacturers and installers.

For your interest a link to the Department of Public Works for Drainage Water Supply and Storm-water drainage can be found here:-