how do you build a hollow concrete block retaining wall

Hollow block retaining wall building process

• Step 1) Excavation and construction of the foundation Excavate the retained earth back to a safe slope. ...
• Step 2) Install the drain and lay the first layer of blocks. ...
• Step 3) Once the first layer of blocks is laid, build the wall to a maximum of 8 courses for 200mm wide walls and 10 courses for 256mm and 325mm blocks. ...
• Step 4) Completion and backfill. ...

Full Answer

How do you build a concrete wall behind a retaining wall?

Fill in directly behind the wall with gravel as you build. For the last two rows of full block, apply concrete adhesive to the wall block tops and then set the next row of block in place. If you're adding block caps, apply adhesive to the top row of block before placing the caps. Fold the excess fabric back.

How much base do I need to build a retaining wall?

You are going to want to make the base around 4–6 inches (10.2–15.2 cm), depending the height of your wall. Also you want to make sure that your base is wide enough so that your block will sit completely on the base. Also make sure the base block is at least one inch below the surface to ensure the gravel base won't wash out underneath. [3]

How do you reinforce a hollow concrete block wall?

You can reinforce a hollow concrete block wall to give it the resistance needed to withstand flexural stress. Lay your first four courses of concrete block wall. On the fourth course, trowel a skim (very thin) coat of mortar on the block. Lay a run of masonry lathe down the entire course of the wall.

How long does it take to build a block retaining wall?

You can build one in just six steps. Concrete blocks are ideal for building walls to hold back the soil after you dig into a slope for a pathway, patio, or another landscaping project. Block retaining walls are generally the same as freestanding block walls but with a few important differences.

How do you build a hollow block retaining wall?

3:129:41Building a Retaining Wall with Concrete Blocks - YouTubeYouTubeStart of suggested clipEnd of suggested clipGet it leveled we get it straight with the one next to it I put a leveled on the backside put aMoreGet it leveled we get it straight with the one next to it I put a leveled on the backside put a level on the front face the back face these are cantered back a tiny bit hit the bottom row.

Do you fill hollow blocks with cement?

2) What you put in the hollow cells is called “grout”, not cement or mortar. Grout comes in “fine” and “course”. You'll probably want “fine”, because it will flow better around rebar, etc.

What do you fill hollow retaining wall blocks with?

Backfill After each row is completed, you should use backfill to reinforce the retaining wall. Use crushed gravel to fill in the back and sides of your blocks. Backfill helps with water drainage.

Should hollow retaining wall blocks be filled?

Retaining wall blocks should be filled, especially if they're made of concrete and have hollow cores. You should fill the hollow cores of every retaining wall block with gravel or crushed rock before starting a new layer until you reach the top and install concrete caps.

Which cement is best for hollow blocks?

Portland Pozzolana Cement (PPC): PPC Cement has a higher degree of fineness, impermeable and corrosion-resistant quality that makes the concrete denser resulting in long-lasting structures. It is used in mass concreting work as well as RCC work.

Should you glue retaining wall blocks?

Retaining wall blocks typically do not need adhesive to lay each course.

Should block wall be filled with concrete?

The reason filling is not recommended in most cases is that as the joining solution (mortar or concrete) you use to join cinder block solidifies, whatever you add within will diffuse the moisture inwards. Not only with that, even if you're adding soil, there will be moisture within. Concrete, of course, will be wet.

Do you need landscape fabric behind retaining wall?

Poor drainage resulting in saturated soil and frost heaving is the main cause of failure. That's why all strong retaining walls begin with landscape fabric, backfill, and 4-inch perforated drainpipe.

Does a retaining wall need a footing?

The key to building a strong and durable retaining wall is a stable footing and proper drainage. A retaining wall needs a footing because if the ground below it shifts, the wall will shirt too and possibly collapse.

Does a 3 foot retaining wall need drainage?

Third, since most retaining walls are impervious, which means water cannot pass through the wall itself, efficient drainage is crucial. When drainage goes unaddressed hydrostatic pressure will build up behind the wall and cause damage such as bulging or cracking.

What is the best material to backfill a retaining wall?

gravelThe best material for the backfilling of a retaining wall is gravel, and it should be well graded. The main reason for using gravel is because it does not retain water (small void ratio); hence lateral loads experienced will be minimal. You should also have weep holes for draining excess water that may be retained.

What is the difference between a cinder block and a concrete block?

Cinder blocks are hollow rectangle-shaped structures usually made of concrete and coal cinders which find use in construction sites. Concrete blocks often, on the other hand, are flattened constructs made of steel, wood or cement.

Are hollow blocks filled?

Contractors elect to fill the hollow openings or voids in concrete blocks (sometimes referred to as grouting) after they are stacked or laid to achieve a stronger wall, one with properties nearly identical to a poured concrete wall.

How much concrete does it take to fill hollow blocks?

To core fill 150mm 'H' blocks allow 0.65m3 of concrete per 100 blocks. To core fill 200mm blocks allow 0.8m3 of concrete per 100 blocks. To core fill 200mm 'H' blocks allow 0.84m3 of concrete per 100 blocks. To core fill 300mm blocks allow 1.1m3 of concrete per 100 blocks.

What to use to fill concrete blocks?

For masonry cores over 4 inches wide, QUIKRETE Core Fill Grout – Coarse should be poured around the rebar; for masonry cores under 4 inches wide, QUIKRETE Core Fill Grout-Fine should be used.

How do you fill concrete block cores?

Pour concrete from the bucket into the cinder block voids. Fill the internal space of the block wall with concrete, pouring from the bucket. Keep filling voids with concrete until level with the top of each block, using the cement trowel to level the concrete.

How long does it take to build a 3x10 retaining wall?

Expect to spend 20-36 hours building a 3x10-foot concrete-block retaining wall. Before you begin, you'll need to design the layout and pour the footing.

What is concrete block?

Rob Cardillo. Concrete blocks are ideal for building walls to hold back the soil after you dig into a slope for a pathway, patio, or another landscaping project. Block retaining walls are generally the same as freestanding block walls but with a few important differences. A retaining wall must provide a way to release the water ...

What is a retaining wall?

A retaining wall must provide a way to release the water that builds up in the slope behind it. Without a pressure-relief system, the weight of the water in the soil would crack or even buckle the wall. Weep holes, which are lengths of 3/4-inch pipe inserted along the top of the first course, escort some of the water out.

What is a weep hole?

Weep holes, which are lengths of 3/4-inch pipe inserted along the top of the first course, escort some of the water out. The other part of the system is a plastic drainpipe covered with gravel. As water accumulates behind the wall, it percolates through the gravel into the drainpipe, which carries it off safely.

How big should a block base be?

You are going to want to make the base around 4–6 inches (10.2–15.2 cm), depending the height of your wall. Also you want to make sure that your base is wide enough so that your block will sit completely on the base.

When digging a trench, do you keep it flat?

Tip: When digging the trench try to keep it as flat and level as possible, so when building the base it will be easier to keep that level and flat as well.

How wide should a trench be?

Also the trench should be roughly 14 to 16 inches (35.6 to 40.6 cm) wide. ...

Can you build a block wall?

A block retaining wall is durable, long-lasting and can be constructed in any form to fit your landscaping needs . Building one of these walls can be fairly simple, depending on the design and size of the wall. This may take you some time and a little physical work, but in the end you will have save money and have a sense of doing your own work.

Can a 2 foot wall be 4x4?

Sure, a 2-foot tall wall can be just 4x4s nailed into the ground with rebar, but anything more may actually kick you, legally, into a fully engineered and approved design. Retaining walls must be built very specifically, or they will majorly detract from a property's value or threaten lives and others' property.

Planning a Block Retaining Wall

There are several retaining wall systems to consider when choosing the building materials for your wall. You can choose regular block that simply stack together for a gravity-held wall, a block system that works with pins for easy and secure assembly or block with an interlocking lip as we did for this project.

Prep and Lay the Retaining Wall Block

Now that you have a plan and a layout, prep the area and begin building the retaining wall.

Retaining Wall Ideas

Once you know how to build a block retaining wall, think about some different DIY landscape ideas for retaining walls.

Where is the vertical bar in a hollow block?

Drop an extra vertical bar in the cell of the hollow blocks located next to any door or window opening. (These areas of the wall are subject to greater stress during storms or seismic activity and require extra reinforcement.)

Can concrete block walls fall?

Concrete block walls can fall easily when the mortar is wet, causing severe injury or damage. Make sure that the area is clearly marked so that no one walks next to a wall that could fall. Building walls using hollow concrete block is an economical means to creating a structure.

Can you substitute fill mortar for concrete block?

You can substitute the fill mortar poured into the hollows of the block with simple dirt. Fill and pack the hollows tightly and it will provide just as much insulation and structural support as the mortar. Warning. Concrete block walls can fall easily when the mortar is wet, causing severe injury or damage. Make sure that the area is clearly marked ...