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Lot Grading

 

The most persistent and challenging enemy of your house is water. If there is any opening at all, it will get in. It will rot the wood, de-laminate the plywood, strip the paint, rust the steel,  and create the perfect environment for mold. The importance of proper lot grading cannot be overemphasized.

Water damage is a major cause of property loss. Whether a flood, a stream, a trickle, a slow drip, or light moisture – damage occurs. Sometimes the damage is immediate and catastrophic. Sometimes it’s imperceptibly slow causing very minor – unnoticeable damage at first. Many a home owner has been shocked to find how extensive the damage had become after working away behind the scenes for a period of time. Water is completely indiscriminate and merciless. It demands your on-going vigilance.

The very best time to apply this vigilance is right at the beginning. When viewing a property for the very first time, the first view should be from across the street – or a short ways back up the road leading to the property. A properly trained home inspector will automatically do this as a matter of course. The inspection will begin even before he/she arrives at the property.

By the way, the second best time to apply this vigilance is NOW. Even if you already have the property and have been living there for years, go out and take a look at it from a short distance. Or, the next time you come home from anywhere, view the property as you approach.

Never mind “curb appeal.” Don’t look at the shutters, the roof, the brickwork or siding. Never mind the flowers in the garden and the bushes.  What you should be looking at is the overall grading of the property. How the water flows on the property is the concern. Does it flow away from the house or toward the house? Does it flow down toward the street and the catch basin or into the neighbors yard? Is the neighbors water flowing into your yard?

Look at the ground that butts up against your house. That part of the ground should not be higher than the foundation wall and you should see an obvious sloping down and away from the house.Lot Grade

*  Where there is grass or gravel or sand or anything else that can be penetrated by water sitting against the house -

there should be a gradual drop of at least 1 inch for every 1 foot        for at least the first 6 feet.

This is a 8.3% slope. There is some disagreement about what the exact slope should be, but as a rule of thumb, this is fairly standard.

 *  Where it is paved against the house – like a driveway or patio – and water cannot penetrate,

there should be a gradual drop of at least 1 inch for every 4 feet

This is a 2% slope. This is standard pretty much everywhere.

Slope

It’s easy enough to measure. All you need is a stick, some string, a line level and a measuring tape. But, really, if you stand back and look at it, you should be able to see an obvious slope falling down and away from the house.

If you can’t see a slope, you may want to get a little more involved and actually measure it.

If you see a slope running down and toward the house - it’s time to get actively involved to correct it.

Mold on Basement WallIf you have a concrete or asphalt driveway or patio that butts right up against the house and the slope is falling down toward the house – this can be a disaster. Water will sit in puddles against the house and can create an environment inside the walls where mold can thrive.

You may also have a porous surface such as top soil, sand or gravel against the house sitting on top of an impervious soil such as clay. The porous surface may slope away from the house, but because it is porous, water will soak down to the impervious clay which may be sloping toward the house underneath.Underground Reverse Grade -

The water can accumulate against the foundation wall here and also create an environment for mold to grow. This, obviously, cannot be seen simply by looking. You should, however, be aware of this possibility.

Another serious concern is the shifting that occurs after a house is built. Ideally, it will not shift at all. But, it is commonly accepted that a new house will shift to some degree as the land on which it sits settles again over a year or two – sometimes longer. This shifting can cause the basement wall to crack. If the crack forms where the water is accumulating on the other side of the wall, the problem becomes about as serious as it can get. This will be covered in depth in the Exterior and Interior categories.

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