How to choose and make the right forms for foam concrete

A crucial step in any project involving foam concrete is selecting and creating the appropriate forms. Foam concrete is lightweight and insulating, but it needs certain molds to form and harden properly. The quality of your final product can significantly vary depending on how you choose and prepare these forms, whether you’re a professional or a do-it-yourself enthusiast.

It’s crucial to first think about the kind of form you’ll need for the project. From straightforward rectangular molds to intricate custom designs, foam concrete forms are available in a variety of sizes and shapes. Consider the final application of your concrete, such as walls, blocks, or other structures, as this will influence your selection. When the concrete sets, your forms should be both easily removed and robust enough to support the weight of the wet concrete.

Although creating your own forms can be rewarding, it does require some basic supplies and tools. Many people construct their forms out of wood or metal, but if you want something more flexible, you can also use silicone or plastic. Whichever material you decide on, be sure to properly seal it to avoid leaks and guarantee a smooth foam concrete surface.

In conclusion, choosing and creating the ideal foam concrete forms requires knowing the requirements of your project, deciding on the right materials, and making sure your forms are strong and waterproof. You can build long-lasting, high-quality foam concrete structures that live up to your expectations if you take the proper approach.

Varieties of forms for foam concrete

Several indicators are used to classify foam concrete formwork:

• According to the material, from which it is made – wood, plywood, plastic, foam, metal;
• According to the parameters – for wall large and small blocks, for grooves;
• By constructive – fully collapsible or integral base with mobile partitions. The former is very simple to store and transport, since all the elements in a disassembled form take up little space when the second type is more reliable in operation.

Formwork for foam blocks can also be identified by their production type, which includes casting and cutting. In the first scenario, the apparatus needs to have partitions for form-forming, whereas all that is required for casting is a sturdy frame.

It is not required to buy extra formwork for the monolith if you have planned the production of cast foam concrete. Instead, you can occasionally practice cutting blocks. You can obtain a cutting-edge version of equipment if you choose not to install partitions.

Forms for blocks must be chosen that satisfy specific criteria in order for the blocks to be obtained with exact parameters and the entire work process to be as simple as possible.

Making and selecting the appropriate foam concrete forms is essential to ensuring the success of your project. Although foam concrete is adaptable and lightweight, shaping and supporting it with the appropriate forms is crucial to its success. This post will walk you through the most important factors to take into account when choosing the ideal forms, such as size, design, and material options. It will also offer helpful advice on how to construct your own forms so that the finish is smooth and long-lasting.

Requirements for foam concrete formwork

It appears that formwork, like formwork, has characteristics that make it unique and that it can relate to. Form flaws can sometimes be the exact cause of defects in foam concrete. Some products are deemed "ugly," the block parameters are imprecise, and the volume is not complete. Thus, what kind of formwork is best for foam concrete?

What are the forms made of

Additionally, when the foam concrete mixture hydrates and hardens in a "steam room," a significant amount of heat and moisture is released, applying significant pressure to the formwork walls. These three elements constitute the "sentence" of any formwork.

It is warped with time. what has an impact on the products’ accuracy. Furthermore, the material that is used to make the formwork determines how quickly this occurs.

• Wooden rough boards – a pilot option at the beginning of the formation of almost any professional or "garage" production. Quite quickly, such formwork fails, and the surface of the products leaves much to be desired. If you decide to use such forms, then before each assembly, the wooden elements must be wrapped in cling film and be sure to lubricate. This will slightly extend the service life and improve the appearance of the blocks.

• Instead of boards, any other plate materials are most often used in production, for example, simple and laminated plywood, OSB sheets. Of all of the above, laminated plywood is the most successful material for formwork, which can withstand any pressure from concrete.
• Plastic. Today, in the market of equipment for foam concrete, you can find modern formwork made of durable technical plastic with reinforcing elements made of metal. Most often, these are forms for tongue-and-groove partition foam concrete blocks.

Manufacturers present this material as an example of a new class of polymers with the highest strength, resistance to extremes in temperature and humidity, and other qualities. Experience has shown us that while these plastic elements are excellent, they are not very long-lasting. "Wavy" blocks are the result of internal partitions and components with ridges and grooves warping.

Of course, you can replace the damaged parts, but doing so will come at a significant additional cost. As an alternative, you could attempt to create comparable components using your own hands or the hands of a skilled tinsmith. Additionally, cutting the partitions from laminated plywood is the best option because its thickness perfectly matches that of the "native" walls.

Another kind of plastic form used in the production of individual foam block products is seen in the above photo. For serial production, they are not profitable. For those who use homemade equipment to make small batches, they are more likely to be a blessing. The plastic will distort with time. Additionally, you must remove the blocks from them with extreme caution because, on the first day following hardening, they become extremely fragile.

• Metal formwork is the most reliable option for serial production. Any element of increased precision can be made from sheet steel blanks. Today, you can buy such forms without any problems. Even among used options, you can find good formwork.

And creating such equipment is not too difficult. If only you had a trustworthy craftsman and the appropriate tools… For concrete formwork, sheet steel grade St3 with a thickness of 2-4 mm makes an excellent raw material base.

• Foam plastic. Since we started talking about forms for foam concrete, it would be unfair to keep silent about permanent formwork made of foam plastic, or as it is also called “Lego blocks”. It is applicable in monolithic construction from commercial foam concrete or any other lightweight mortar. Such forms are prefabricated hollow structures with a convenient and reliable system of fixation between them.

Using such formwork in serial production is absurd, even though it is widely used in construction. Nevertheless, because the foam itself prevents moisture from passing through and produces a greenhouse inside the space, it has recently been abandoned. The pouring of the mixture into plastic forms for foam concrete is demonstrated in this video.

Accuracy of parameters

Since concrete will accept any errors, formwork used to pour concrete products must be flawless. Consequently, these goods are either rejected or divided into smaller ones and sold as first or second grade. Either way, there are financial losses as well as labor expenses to fix the faulty product.

Regarding foam concrete, the assembly seam thickness should be minimal because the foam concrete mass just seeps through these gaps when pressured. Additionally, the loss of solution increases with their size. Thus, exercise caution when purchasing used formwork. One of the possible reasons for selling is the potentially wide gaps between the elements.

There is no bottom to the metal foam concrete formwork that is pictured above. In any event, when pouring, the foam concrete will be forced out of these areas. You can easily avoid this by lightly sanding the formwork’s edges so that the fill fits the form very tightly.

Simplicity

The longer the formwork lasts, the fewer extra pieces there are. If you create the forms yourself, offer the most straightforward assembly method while still maintaining reliability. Let’s look at a suggestion that is comparable in the pictures below.

• Pay attention to the fastenings of all three models of forms. In the first photo there is a simple metal retainer, in the second – grooves, and in the third – a bolted connection. Of the options presented, the first type of fastening is considered the most convenient and durable. If the metal retainer is lost or "loosened", you can always make a "double" to replace it yourself.
• The formwork option shown in the second photo requires several people to service it, since one person will not be able to put the side boards in place. In addition, there is a risk that the formwork will be mounted unevenly. And in the collected state, one push of the mounting boot is enough so that part of it is skewed. So it turns out curved blocks. All because there is no bottom that gives stiffness.
• The third photo shows the classic version of the groove formwork with screw joints. But also on ordinary metal forms there may be such fasteners. Of the pluses only reliability, and even then the thread is erased over time. In addition, in order to fix the parts of the formwork well, you need to attach considerable strength. When the solution enters such a latch, it will be quite difficult to promote it.
• Of the presented three types of formwork, the most convenient and reliable first. His more detailed photos are presented below.

This form is really convenient to use. Pull out the blocks gradually after opening the main sides. There are even special "ears" welded on so as not to damage the delicate foam concrete "body" when removing the partitions, which fit quite snugly because of the lubricant. Additionally, a straightforward but dependable fixation is offered to ensure that the same partitions do not move out.

Versatility

The completed formwork is meant to be used in the manufacturing of GOST-sized foam blocks.

The following are the typical specifications for foam concrete products:

• wall – 600x300x200 mm;
• small – 200x200x200 mm;
• partition – 600x300x100 mm.

But in the real world of industry, anything can happen. Customers who are willing to pay any amount for the serial production of non-standard blocks are known as "twist customers." Furthermore, losing a client is never fun.

Because of this, it is ideal to buy or make universal molds, which can be used to create blocks with standard dimensions and, when assembled differently, allow for the filling of products with different dimensions.

Storage

Not all formwork will be heavily utilized during production. One day you’ll just have to take it apart and store it in a distant corner. It is crucial that the formwork occupy the least amount of space possible during disassembly.

Once you’ve determined what specifications a good foam concrete form should have, you can attempt to make one yourself.

In any construction project, selecting and creating the appropriate foam concrete forms is an essential step. The final result can be greatly impacted by the quality and suitability of your forms, regardless of whether you’re working on a small DIY project or a larger building. You can guarantee a successful and seamless process by being aware of the important variables, such as the kind of foam concrete, the shape of your project, and the materials needed for the forms.

Take into account the particular requirements of your project first. Different forms might be needed for different kinds of foam concrete. Consider the measurements, the desired surface roughness, and how simple it will be to remove the forms once the concrete has hardened. This will help you choose or create forms that best meet your needs.

If you are creating the forms yourself, make sure the materials are strong enough to support the weight of the foam concrete. Common options include plastic, metal, and plywood, each of which has advantages of its own. To prevent any accidents when pouring and setting, make sure your forms are well-built and firmly fastened.

Keep in mind that the final concrete’s durability and appearance will be influenced by the quality of your forms. Selecting or designing the appropriate forms will not only simplify your work but also improve the project’s final result. You can use foam concrete to achieve excellent results if you use the proper forms.

Video on the topic

New forms for foam concrete blocks must be processed and lubricated!

The most convenient and best form for foam concrete blocks!

Molds for foam concrete # 1 – Polystyrene concrete

molds for foam blocks

Mold for foam blocks assembly of a mold for the production of foam blocks