Flood- Proofing a Building

The Types of Flooding and How to Protect Your Home

Over the last 100 years, flooding has claimed millions of lives the world over. No location is truly safe from flooding as the cause of flooding is varied. A flood can materialize after hour or days of excessive rain. In cases where flood develops under six hours of rain, then that is what is known as flash flood. There are four basic types of flooding: river flooding; coastal flooding; urban flooding and flash flooding.

There are three ways that your house can be "flooded". Water can enter your house through any of the four types of flooding, by sewer backup and by water seepage from the ground.

It seems like there are ways to escape flooding. If you don't want to experience river flooding, don't live near any river. If you don't want to be a victim of coastal flooding, move out of from that coastal home. If you don't want to experience catastrophic flooding in terms of dams and water reservoirs breaking, make sure your house is out of a dam's water release path. Easy enough. However, what do you do in case of urban flooding? Or if the sewer backs up or if groundwater seeps into the basement? You might just have to flood-proof your home.

Flood-proof Your Home before It is Built

The rule of thumb when considering the elevation or height of the ground floor from the main street to which the structure faces is to elevate the ground floor at least one metre from the centre of the street. The one metre difference would give you ample height in case of flooding. Currently a two metre difference from the centre of the street to the structure's ground level is better.

If you have a basement in the house, make sure that the walls are plastered with mortar that has a waterproofing additive. The waterproof additive or vapour barrier would slow down if not totally stop moisture from seeping in. It is best to elevate your basement from the street level by at least 600 mm.

Build the ground around the foundation sloping out of the house. Ideally a slope of one inch per foot for the first six feet will do. You can also install a false floor over the basement floor to allow water to flow to a sump pump. An interior or exterior drainage system is highly recommended for homes located in flood-prone area. Remember to have a qualified plumber install a backflow valve to keep water from backing up through the drain.

If your house is likely to be flooded it is best to locate electrical panel way out of the anticipated flood level. If it's allowable, better install the electrical panel on the upper floor. Make sure the heating ducts are insulated and watertight.

There's only so much that you can do. However, the above pre-construction suggestions will help to an extent, flood-proof your home.

Flood proofing for already Built Homes

If your area is prone to flooding, relocate the electrical panel above the anticipated flood line. If flooding is only from 3 to 4 inches, install a float plug in the drain. This will not work for deeper water in the basement though. Some other measures that you can do are: