Chapter 18 – Inspecting Perimeter Grade

We will continue our inspection with the perimeter grade.

The perimeter grade is probably one of the most overlooked conditions of a property. Most building contractors are only concerned with the initial grade. The initial grade must take into account the position of the building on the property as related to streets, property line set backs and natural drainage. After the building is signed off for occupancy the condition of the grade becomes a maintenance issue.

The exterior grade should slope down and away from the building so that all surface water drains away from the foundation. Proper grade will alleviate water problems around the building. Water causes more property damage to homes than any other factor including natural disasters and fire.

Water that is allowed to pond around the building or reach the siding will cause deterioration. Water can leach into the interior of the building or crawl space causing potential deterioration to the building framing. Erosion around the foundation footings and deck piers can occur. When the base of wood posts and piers are allowed to come into contact with water or soil they become subject to deterioration and attract insects.

Water that collects at the foundation and flows over concrete surfaces seeps into the cracks. If the water freezes it will expand in the crack. The continual freeze/thaw cycle will erode the concrete and cause it to flake and deteriorate.

Foliage and debris must not be allowed to collect around the building. Areas subject to wild fires are required to maintain defensible space around homes and structures as a measure against fire damage.

Runoff from the roof is also a part of this system. Water draining off of the roof has to be diverted away from the building by the slope of the grade. This may require additional measures such as gutters and downspouts.

Direct the water exiting the downspouts away from the foundation.

The home inspector will make notes when drainage problems are found. The Photo Gallery will provide additional information.

You know your property best. Record any areas where water ponds or flows towards the building.

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PERIMETER GRADE FINDINGS: REMEDIES AND SOLUTIONS

Grade problems are primarily a maintenance issue. Rake the ground around your home so that the soil slopes down and away from the foundation.

If you have a driveway, sidewalk or patio decking made of concrete, brick or asphalt that butts up to the foundation the surface should be constructed to slope away from the building.

If you have planter boxes that trap water between a walkway and the building, a drain system may be necessary.

Install water diverters or drain pipes to downspouts and at areas subject to runoff from the roof.

Restore any soil erosion that may have occurred around the foundation footings and deck piers.

Issues that require more attention should be referred to a professional landscaper rather than a building contractor.

In some cases a French drain systems may need to be installed to capture water as it flows towards the building. A French drain is constructed by trenching a ditch perpendicular to the direction of the water flow. The trench has a perforated pipe at the bottom, a fabric mesh to prevent slit from clogging the pipe and is filled with drain rock. Any water that is running over or through the soil will take the path of least resistance and run into the drain rock, leach down to the pipe and then flow to the exit point.

French drains are often necessary to capture water that migrates through the soil around areas of below grade construction. Moisture issues in basements and subterranean rooms can be resolved with non-permeable material affixed to the underground portion of the wall and a French drain installed just below the foundation footing.

PHOTO GALLERY

An additional 12 images with descriptive captions are available in the 27 Dollar Home Inspections eBook.

Click here to move on to
Chapter 19 – Inspecting Stairs, Steps, Walks & Decks