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Property on a Hillside or a Steep Slope, May Be at Risk and need Slope Repair.

Slope repair strengthens the slope's resistance to erosion. It corrects slope instability and protects your home and your family from the potentially catastrophic effects of landslides.

So if your home is located on the side of a hill or on a steeply sloping site, you may have a future problem with your property.

Mother Nature typically tries to reduce the gradient of most slopes — and the steeper the slope, the more prone it is to instability and problems.

If you have a hillside property and it is showing signs of foundation damage due to slope instability, slope repairs must be carried out IMMEDIATELY.

A classic example of slope failure.
A classic example of slope failure.

When you have a house on a slope, and nature is left to do it's work, the hillside and your homes foundation are at risk.

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Negleted, the  unstable slope gets worse.
Negleted, the unstable slope gets worse.

Wind, rain and gravity work to move the dirt around your homes foundation away from your house and down the hill.

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Gutter at the bottom of the stable slope.
Gutter at the bottom of the stable slope.

Slope repair includes an embedded PVC pipe that directs water from the slope to the concrete gutter. The gutter takes the water away from the house and it's foundation.

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A classic example of slope failure.
A classic example of slope failure.

When you have a house on a slope, and nature is left to do it's work, the hillside and your homes foundation are at risk.

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Do You Need Slope Repair?

A hillside foundation specialist should be able to tell you for sure if you need to have your slope stabilized. Basically, if you own a hillside property and its foundation or any one of the foundation's components is showing signs of failure — you must seek professional help.

Look out for Signs of Foundation Damage

The following may indicate that one or more components of your foundation are failing. Again, it should be stressed that if your home is located on a steep slope, a failing foundation may be early warning signs of slope instability.

  • Your floors have become out of level.

  • Parts of your home seem to be pulling away or tilting.

  • There are cracks in your foundation, walls and floors.

  • Your doors and/or windows stick or are misaligned.

  • There are gaps around your doors and/or windows.

  • There's apparent soil movement away from the foundation.

  • There's moisture in your basement/crawlspace walls and other signs of water intrusion into your foundation.

Look out for Signs of Slope Instability

The following may indicate a recent slope movement or impending slope failure:

  • Exposed soil shows signs of recent erosion and/or tension cracks parallel to the contours of the land.

  • There are bulges, cracks and water seepage were there were none before.

  • Certain areas in the ground have sunk or dropped.

The following may indicate long-term soil movement — what is known as "downhill creep":

  • The trees in and around your property show signs of leaning or have curved trunks. This can be a sign that they have tried righting themselves during growth.

  • Other fixtures in your property or neighborhood (including utility poles and fences) also show signs of leaning or tilting.

Look out for Potential Triggers of Slope Instability

Even if your property has shown or shows no signs of slope instability, you could be at risk if it has just undergone a deluge from heavy rains or melting winter snow. Heavy rains and melting snow can saturate the soil. This change in the soil's water saturation levels could lead to adjustments in its angle of repose, which could in turn cause landslides.

Even if it doesn't immediately lead to erosion, water saturation of the soil could cause gradual settlement which, if left unchecked, could eventually lead to foundation damage.

What to Expect in Slope Repair

Sinai Construction Engineering prevents slope instability, strengthens unstable slopes or repairs/restores damaged slopes using the most appropriate techniques given specific site conditions. Our field personnel are trained and qualified; we use the most cost-effective approach to fit our clients' budget requirements, and we employ construction methods that reflect the latest developments in engineering geology and engineering technology. Depending on your property's needs, we may use one or a combination of the following methods:

Friction Piles

Friction piles are usually used as a preventive measure and installed in sites that are susceptible to lateral soil movement. The piles may be isolated and designed as soldier piles or provided with a panel or lagging and designed as a retaining wall. Lagging is placed between the piles as a barrier. This acts as a retaining wall and prevents the soil between the piles from moving downward.

Keying and Benching

This is a necessary step in slope repair. If the slope has already failed and the earth materials are to be replaced as part of the restoration, the compacted, replacement fill must be keyed and benched (stepped) into the underlying competent material.


Geo-grid is a heavy gauge plastic mesh used within layers of the approved compacted fill to strengthen the fill. This is usually used when a gradient slope steeper than the maximum allowable 2:1 (26 degrees) is required. Geo-grid is a cost-effective slope repair solution as retaining walls may be eliminated to create a larger level area.

Retaining Walls

Retaining walls are generally used to increase the size of a level pad area or for subterranean portions of a structure.

Retaining walls less than 4 feet in height with a horizontal back slope are typically allowed within the City of Los Angeles, provided that the standard engineering information provided by the City is used. Walls in excess of 4 feet high will require obtaining a Geologic and Soils Engineering Exploration report, survey, and structural engineering before a permit could be issued.


Shotcrete refers to concrete that is pneumatically applied over a grid of reinforcement bars, which have been properly anchored to the slope. Shotcrete is used to stabilize slopes when the slope face consists of bedrock.

The City now requires a Geologic and Soils Engineering Exploration report, survey, and structural engineering in order to obtain a permit for the use of this construction technique. Shotcrete for slope stabilization is considered to be a remedial repair.


Poor drainage control is the most significant potential problem for hillside sites. Fortunately, it is also the most preventable.

Each site has specific minimum drainage requirements, and statistics show that concentrated drainage typically results in erosion and slope failures. Thus, before building on a slope or before repairing a damaged slope, you should have an engineering geologist inspect the site to evaluate its drainage conditions and provide drainage recommendations.

Our home was being destroyed inch by inch because of slope failure. To be honest, I thought the damage was beyond repair but Sinai Construction proved me wrong. They presented me with a project plan that is both affordable and more importantly effective in providing a permanent solution to the problem. Two months and extensive concrete reinforcement later, I can say that our home is even more stable now than it was when brand new!

Ellen G., Mount Washington

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