How To Build A Retaining Wall On A Hill

How to build a retaining wall on a hill

The maximum slope for the soil you can safely go without having a retaining wall is 35 degrees. This is especially important if the soil is granular. If the angle is steeper than 35 degrees, you need a retaining wall to keep the landscape in place.

What is the cheapest type of retaining wall?

The cheapest type of retaining wall is poured concrete. Prices start at $4.30 per square foot for poured concrete, $5.65 for interlocking concrete block, $6.15 for pressure-treated pine, and about $11 for stone. Installation or supplies, such as drainage stone or filter fabric, are not included.

How do you install retaining wall blocks on slope?

How to Lay Landscaping Blocks on a Slope

Use String and Stakes to Mark the Location.
Measure the Blocks. ...
Compact the Base. ...
Add Crushed Gravel. ...
Lay the First Set of Blocks. ...
Dig the Trench Up the Slope. ...
Check for Levelness. ...
Add Another Set of Blocks.

How high is too high for a retaining wall?

Most retaining walls, whether load-bearing or not, average between 3 and 4 feet in height. As a general rule, you do not want to build any sort of structure over 4 feet in height without including some type of structural support within.

Does a 2 foot retaining wall need drainage?

Every retaining wall should include drainage stone behind the wall. Though it is a good idea to install a drainage pipe on all walls, there are certain situations where a perforated drain pipe is absolutely necessary.

What is the steepest slope you can build on?

The ideal slope for in-ground building is a slope of 5 to 7 feet through the width of the house, or 15% to 20%. Building on steeper slopes often presents challenges, and this type of construction is carefully regulated by local jurisdictions that vary, as do local soil types.

What is the best DIY retaining wall?

For DIYers, it's best to use concrete retaining wall blocks, which can be interlocking and are heavy enough to stay in place without cement or other adhesive. Interlocking blocks fit together and add extra security to the wall.

Does a small retaining wall Need foundation?

The foundation of a retaining wall is a key component in the wall's longevity. A good foundation ensures the wall does not sag or settle. It will ensure the finished wall is level and straight.

What is the cheapest and easiest way to build a retaining wall?

The cheapest way to build a retaining wall is to DIY it. And the most DIY-friendly way is to use commercially available concrete blocks, sold in Home Depot or Lowe's. They commonly come as self-aligning and trapezoidal in shape which makes it easier to form concaves, convexes, or straight walls.

Do you have to pour a footing for a retaining wall?

Every retaining wall needs a footing, but what type depends on the design, material, height and weight of the wall. Large masonry retaining walls built out of rigid materials like concrete, cinder blocks, cement or brick need a concrete footing. Solid masonry walls are stiff and unable to flex because they'll crack.

Can a retaining wall follow a slope?

Design and build your retaining wall to slope at a minimum rate of one inch for every one-foot of rise (height). Fortunately, working with retaining wall blocks makes it incredibly easy to achieve this “step-back” construction!

Can cinder blocks be used for retaining wall?

A cinder block retaining wall is only as straight and solid as the base it's built on. For a 4-ft. tall wall, excavate a trench deep enough to accommodate 4 to 6 in. of compacted base, 1 in.

What should you not do when building a retaining wall?

However, if you're confident in your skills to tackle this project, these are the mistakes you should avoid when building a retaining wall.

Choosing the wrong material.
Failing to provide adequate drainage. ...
Putting too much weight behind the wall. ...
Tackling too much wall on your own. ...
Not doing maintenance.

At what height do you need a Deadman for retaining wall?

Install one dead man every 6 to 8 feet around the entire wall. Continue building up the retaining wall, using landscaping screws to secure each timber. Cover the ground in front of the retaining wall with 2 to 4 inches of bark mulch.

How big of a footing do I need for a retaining wall?

Rules of thumb commonly used by designers to establish the geometry of the wall include (refer to diagram): Base width = 1/2 to 1/3 of the height of the wall. Base thickness = 1/8 of the height of the wall but not less than 12 inches. Stem thickness = 6 inches + ¼ inch for each foot of wall height.

Should I put gravel behind my retaining wall?

Second, a retaining wall must have properly compacted backfill. Backfill refers to the dirt behind the wall. In order to provide proper drainage, at least 12 inches of granular backfill (gravel or a similar aggregate) should be installed directly behind the wall.

Do I need to put landscape fabric behind retaining wall?

Filter fabric is an essential step in the process of building a retaining wall because it lets water through but prevents dirt, bark dust, or other landscaping from migrating into your gravel base. First, measure and cut the length of the space you need to cover.

What happens if you don't put drainage behind a retaining wall?

If there is no drainage, water will compromise the safety and structure of your retaining wall. It's vital that the wall is repaired or replaced if measures to ensure drainage weren't taken. This can lead to an extensive amount of damage on the property, the expense of repairs and installation of a new wall.

How steep is a 20% grade hill?

In surveying 20% is interpreted as 20% of a right angle (i.e. a brick wall) and so would be 18 degrees.

How much more expensive is it to build on a slope?

A developer in Washington County mentioned that the value of a downhill lot is, “33% less than flat lots”, while uphill lots could be as much as, “40% less” valuable. One reason for the difference is that it is easier to build foundations downhill than it is to carve them out of an uphill slope.