Public Works: Floodproofing

When Water Attacks: A Homeowner's Guide to Floodproofing

Part I : Flooding

Part II : Basement problems

Basement Problems: Cracks
Groundwater can seep into your basement around pipes if there are cracks in the walls or floor. This may be difficult to determine if the walls have been covered with paneling or other finishing. The best way to deal with a groundwater problem is to waterproof the walls and relieve the water pressure through a footing drain system and sump.

Cracks can be repaired and the walls can be waterproofed from the inside or outside. Waterproofing on the outside is more effective because groundwater pressure forces the sealer into the foundation. The best technique is to dig a ditch around the basement walls so that you can apply a commercial sealant to the exterior walls. This can be done by the handy person (many home maintenance manuals have instructions for this) of a commercial waterproofing company.

Precautions
Waterproofing alone is only recommended for groundwater problems. Surface water will put much more pressure on the building's walls and can even break them. If the building is affected by surface flooding, you should also install a barrier.

This type of work is hidden. A sloppy job may not show up for several years. Be sure to ask the waterproofing supplier or company to provide references of buildings in your area that have used their material or technique. Call their past customers to confirm the quality of their work.

Basement Problems: Sewer Backup
A sanitary sewer line often drains toilet waste, laundry tubs, and (sometimes) the basement floor drain to the sanitary sewer main in the street. Clean stormwater and groundwater is handled by downspouts, footing drains, and sump pumps.

Often basement flooding is caused by these two sewer systems being interconnected. Some houses have downspouts, footing drain, and/or sump pump connected to the sanitary sewer service. During a heavy rain, stormwater enters the sanitary sewers, causing backups into one house and overloading the main lines, contributing to backups in other houses.

Sewer backups can also be caused by events not related to storms and flooding. Individual service lines can be plugged by grease, waste, tree roots, breaks in the pipe, or saturated ground. Proper maintenance, like pouring tree root killer down the toilet each year, can prevent most of these problems. The sewer mains can also be plugged b the same causes as well as vandalism or illegal placement of items in manholes. These problems can be fixed by the owner or your community, depending on where the stoppage occurs. There are four ways to stop sewer backup: floor drain plug, floor drain standpipe, overhead sewer, and backup valve. Each of these measures works for buildings with basements or below-grade floors.

Part II.a : Basement Protection Berm
Part III.a : Sewer Backup Prevention - Floor Drain Plug
Part III.b : Sewer Backup Prevention - Standpipe
Part III.c : Sewer Backup Prevention - Overhead Sewer
Part III.d : Sewer Backup Prevention - Backup Valve
Part IV : Insurance