QA

Question: How Build Retaining Wall

Can I build a retaining wall myself?

While retaining walls taller than four feet should be engineered by professionals, you may be able to DIY a solution for a tall slope by creating two or more shorter “tiered” retaining walls as opposed to a single tall wall.

What is the cheapest way to build a retaining wall?

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.

How deep should a base be for a retaining wall?

The general rule of thumb is to bury about one-eighth of the height of the wall. For example, if your wall will be three feet (36 inches) tall, the first course of blocks should start five inches below soil level. The gravel base should start three inches below this.

Does a 2 foot retaining wall need drainage?

These walls need a drainage system regardless of the wall height. If there are poor draining soils such as clay behind the wall, there needs to be drainage incorporated the wall system. Clay when wet is very weak, so it is essential to provide a way for water to escape from behind the wall.

Can you use sand as a base for a retaining wall?

To keep the blocks on your retaining wall level and structurally sound, you need a base layer of several inches of well compacted, sharp gravel. Be sure to use coarse builder’s sand, and tamp it down firmly to keep the sand from shifting and settling after the wall is built.

How much should I budget for a retaining wall?

You’ll pay between $250 – 550 per square metre for a retaining wall in Sydney.The cost of retaining wall materials in Sydney. Retaining Wall Material Price Per Square Metre Poured Concrete $200 – 250 Treated Pine $50 – 150 Hardwood $100 – 250 Stone Veneer $110 – 150.

Is wood retaining wall cheaper?

The cheapest types of retaining walls are wood and concrete blocks, followed by concrete and stones or bricks. Each material has benefits and drawbacks, including strength, longevity, and attractiveness.

What can I use instead of a retaining wall?

Reinforced Soil Slopes. Natural Stone Walls. Wooden Timbers. Gabion Walls. Soil Bioengineered Walls.

Do you need gravel behind retaining wall?

Second, a retaining wall must have properly compacted backfill. 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. Compacted native soil can be used to backfill the rest of the space behind the wall.

At what height does a retaining wall need to be engineered?

Most municipalities require a building permit and a design from a Licensed Engineer if your wall is taller than 4 feet high (measured from the bottom of the first block to the top of the last block).

How high can a sleeper retaining wall be?

This system works for sleeper walls up to 1200mm in height; anything higher than 1200mm needs to be designed by an engineer to take account of local ground conditions and loadings.

How many dead men do you need in a 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.

How long should a Deadman be on a retaining wall?

Deadmen should be at least 1 1/2 times as long as the wall is high at the level where they’re inserted. This allows them to penetrate beyond the soil that’s actually bearing on the wall.

What kind of wood should I use for a retaining wall?

The best kind of lumber for these walls is Douglas fir pressure treated with preservatives to discourage rot. It will be green or brown in color and rated for earth-to-wood contact. For timber walls, large timbers for can be very expensive, which is why railroad ties are a common alternative.

Does a 4 foot retaining wall need drainage?

Any reinforced wall or walls over 4 ft. (1.2 m) in height or with slopes or other surcharges above the wall will need a toe drain. In all cases wall rock is located within the cores of the block and a minimum of 12 in. (300 mm) behind the block.

Can you build a retaining wall on concrete?

While you can build a retaining wall on concrete, it isn’t that straightforward. If you have an existing concrete base, you cannot just build your wall on top of it. Without being secured into the concrete, your wall will slide due to the soil pressure against the wall.

How long does it take to build a retaining wall?

Plan on about three days to build a wall 4 feet tall by 15 feet long. Cost: $10 to $15 per square face foot installed, depending on your region—higher if extensive excavation, soil prep, and backfilling are needed.

What do you backfill a retaining wall with?

What Should You Use to Backfill a Retaining Wall? The best materials for backfill are native soil for the base and top, with gravel or aggregate forming the body of the backfill between the native soil.

What is the best gravel for retaining wall?

Adding proper backfill to your retaining wall is extremely important as this is a key element in helping divert water away from the back of the wall, eliminating hydrostatic pressure, the leading cause of retaining wall failure. RCP recommends using clean 3/4″ Crushed Gravel as backfill.

Should retaining walls be level?

A retaining wall should be level. The leveling process begins at the most vital part of your wall, the base. With a level base, the rest of the wall will naturally follow suit as you lay additional layers of blocks.

Is a retaining wall expensive?

According to Inch Calculator, the average cost of a retaining wall is around $5,000, though the total cost can fall anywhere between $3,000 and $8,000, depending on the height of the wall. For a standard 3-foot retaining wall, $5,000 is a good estimate.

Who pays for the retaining wall?

The maintenance of a retaining wall is the responsibility of the property owner whose land the retaining wall benefits. There may be circumstances where a retaining wall has been constructed on the boundary that retains fill on one property and cut on the neighbouring property.