Precast concrete wall: everything you need to know

What is a precast concrete wall?

A prefabricated concrete wall is a set of exterior walls around the periphery of a dwelling, building, or structure, constructed by using concrete elements previously made in a factory and then transported and installed at their final location.

These walls generally separate the exterior elements from the interior environment. They are used in the construction of exteriors and have a variety of applications for both residential and commercial projects.

Most precast perimeter walls are made up of rectangular or square concrete slabs – called panels – and concrete columns. This system results in easy, quick and inexpensive assembling.

The panel type elements of the wall can be built in a wide range of colors, finishes and textures, according to the client’s tastes and objectives.

The use of prefabricated panels in the construction of walls has become more and more common since they present a variety of advantages such as fast installation and good results.

Uses of precast concrete walls

Precast perimeter walls have multiple uses. These are:

• Privacy and noise reduction

Precast perimeter walls provide the privacy homeowners seek. In addition, the thick concrete walls naturally reduce noise pollution and create a zone of peace and tranquility for the inhabitants inside your home or business.

• Security

Concrete perimeter walls not only create a feeling of security, but are also tough enough to withstand strong winds. These heavy-duty panels are a great barrier against weather and other natural disasters. Its height and thickness are a deterrent to possible theft or criminal activity.

• Low maintenance and easy installation

You will be surprised how easy it is to install walls. Because the materials are prefabricated in a factory, they arrive at the construction site ready to be installed. This means that weather and other environmental factors do not affect its construction.

Since the perimeter walls are manufactured from molds, their size, durability and availability can be guaranteed to suit each project.

• Aesthetically pleasing

A concrete perimeter wall can be any color, made in any shape using custom molds, and designed with a specific look. The result is clean lines, sleek styling and modern design that will delight both the landowner and the surrounding community.

• Inexpensive

Since the process to create a precast concrete wall is simple, very little material is wasted. You can also estimate the amount of time it will take to make the molds, depending on what has been chosen for the structure.

Once installed, the walls are easy to maintain and durable, making the entire process the most cost-effective option for perimeter walls in your residential or commercial project.

How much do precast perimeter walls cost?

Depending on its heigh, the installation of a prefabricated concrete wall in Venezuela costs on average between $40 and $55 per square meter and the average cost for its installation can be between $15 and $25 per square meter depending on the equipment and tools required.

In addition to the complexity of access to the construction site, this enclosure system requires much less labor than the traditional construction method of block walls with brace beams, crown beams and buttresses.

Differences between precast perimeter walls and block wall type walls

The main differences are:

The prefabricated perimeter walls are solid barriers with greater resistance and greater hardness, as they are made as a single piece with reinforcing steel. Synthetic fibers can also be added to increase its resistance.

The block walls are built with hollowed-out low-resistance concrete blocks and due to their design are of medium fragility, in addition to the fact that in the wall-type structure only the beams and columns have reinforcing steel.

Some other differences have to do with:

• Block structure

Concrete blocks are built with a hollow center. This is to reduce the weight of the blocks, making them easier to stack. Precast concrete is not, it is solid, this makes the block heavier, although it is often thinner than a concrete block wall.

• The precast is solid

Precast concrete walls are typically thinner than block walls, but are made with reinforcing steel inside. Precast concrete uses larger components for its construction.

• Precast can be faster

Precast concrete walls go up faster because they are installed as one large unit, rather than being built from individual components.

They use less labor on site, but require a crane or similar heavy equipment for installation, which increases costs. They are usually placed on a compacted gravel base, while concrete blocks are placed on a solid concrete base.

• Design flexibility

With block walls, your wall can only look like any other, as you don’t have a wide variety of styles to choose from. You can paint it, but this can be time consuming and difficult.

With precast concrete, there is much more flexibility in the design and appearance of the wall. You have an endless number of designs to choose from, as custom walls can be created.

Do you want a fun, long-lasting color or an interesting texture? Pigments and additives can be added to the concrete before it is poured into the forms.

• Manpower

Concrete blocks are set with mortar or dry stacked with a thin layer of concrete covering the entire wall. Regardless of how the concrete wall is built, the blocks will still need to be stacked one by one and will usually require a skilled worker to do so.

Precast concrete does not require specialized workers for its installation. The only thing you might need, depending on the size of the wall panels, is a crane or other machine to help lift them into place. Each panel stands on evenly spaced posts and slides into place.

• Methods of reinforcement

Reinforcement is commonly added to concrete structures to make them stronger. Reinforcement is used in both precast concrete walls and block walls; however, the installation methods are very different.

Precast concrete typically has a steel mesh grid that is placed inside the mold. When concrete is poured into the form, the reinforcing steel is covered by the mix.

Concrete blocks are usually hollow. As the concrete blocks are stacked, the steel rods are randomly placed in the gaps in the blocks. A grout or concrete mix is ​​used to fill the center and hold the reinforcement in place.

If the size of the reinforcing steel and the number of bars placed is similar, the concrete blocks will have a strength very similar to that of precast concrete walls.

Advantages and disadvantages in the use of prefabricated walls

Advantages:

• Save build time
  Building a precast perimeter wall saves time, thus the risk of project delay is lower. The casting of prefabricated concrete elements can be carried out simultaneously with other work on the construction site, such as earthworks, surveying, among others.
• Quality guarantee:
  The key factors that regulate construction quality, such as curing, temperature, mix design, formwork, can be controlled for precast concrete. Therefore, quality in construction improves.
• Profitable:
  Simplified construction process reduces time, increases productivity, quality and safety and therefore construction prices.
• Durability:
  The precast concrete structure has a longer service life and minimal maintenance. High-density precast concrete is more resistant to acid attack, corrosion, impact, reduces surface voids, and resists dust accumulation.
• Aesthetics:
  Since the structures are prefabricated in a controlled environment, various combinations of colors and textures can be used. A wide range of shapes and sizes are available to choose from with a smooth finish and thus increase the aesthetic value of the products.Disadvantages:
• High initial investment:
  Prefabricated elements are more expensive because they require a sophisticated industrial manufacturing process. It involves special machines and equipment, and then transportation to the final location and installation, with cranes and special machines. That is what raises the initial costs for the user.
• Transportation problem:
  The construction site may be located far from the precast concrete plant. In that case, the precast blocks must be transported to the site using large, fully loaded trucks. In many cases, the cost reduction of precast is offset by the cost of transportation.
• Handling difficulties:
  Proper care and caution must be used when handling precast blocks. They are usually heavy and large, making them difficult to handle without damaging them. In general, portable or tower cranes are used to handle and work with these blocks.
• Modification:
  In the case of prefabricated structures, it is difficult to modify the structure. If a structural wall is to be dismantled for modification, it will affect the overall stability of the structure.
• Chances of faulty connection jobs:
  The assembly of the blocks for a perimeter wall is one of the key points to guarantee a strong structural behavior. Connections between various structural elements must be supervised and made correctly to guarantee the expected behavior of the connection.Faulty connections can cause water leakage and sound insulation failure.