Should I Use A Long-Term or Short-Term Use Forming System?

2018-01-18

When deciding to pour concrete, you must first decide if you’ll use a long-term use or short-term use concrete forming system to complete your project.

As both long-term use and short-term use forming systems offer unique benefits, in this article, we’ll review the types of forming systems as well as the pros and cons of each – to ensure you’ll be able to make the decision that is right for you.

Forming Systems

Concrete forming systems are used to create a temporary mould for concrete to be poured into. Once cured, the systems are removed, exposing the concrete underneath:

Long-Term Use Systems

Long-term use concrete forming systems provide a rigid framework for concrete to be poured and cured. With long-term use systems, many of the components are re-useable and are easily modified to create custom wall dimensions and angles.

Panels are prefabricated in multiple sizes and support bar configurations to suit the customer’s needs. They are made using steel or plywood with a high density overlay (HDO) to create a very smooth surface that offers easier and cleaner removal of the forms from the concrete, while also protecting the wood from the damaging affects of water. This allows the forms to be used many times before needing to be replaced.

Since support bars come attached to the panels, installation is much quicker and easier than short-term use systems, allowing the crew to complete walls faster. Forming ties are available in many lengths and are the only non-reusable component to the system. 

These systems are superior to other forming system, but they are costly to get started. Since the panels are prefabricated, they cost more per square foot than traditional Formply sheets. Additionally, the required accessories can only be found at stores that specialize in concrete forming. This all being said, your labour savings will quickly offset the higher cost of the forms. 

Long-term use forms are ideal for any contractor that is regularly pouring concrete walls for residential or commercial use. This could include basements, retaining walls, or commercial buildings.

Short Term Use Systems

Expanded Wire Mesh

Expanded wire mesh is gaining popularity in the world of concrete forming due to its ease of installation and minimal accessories required.

Made from ribbed sheet metal with diamond shaped holes, this material is simply wire tied together and staked in place external support. Concrete can then be poured directly into to formed mould. The holes in the mesh are small enough to contain the concrete and the minimal amount that flows through the holes enables the mesh to become one with the concrete and reduces the need for other reinforcement. 

Please note that though this product is economical and easy to install, it cannot be re-used, and it does not create a smooth aesthetic.

Expanded wire mesh is ideal for contractors that work in civil or commercial applications. It can be used to form blindside walls, grade beams or any other area where forms would be inaccessible after the pour. It can also be used in any application where a smooth finished concrete is not required.

Formply

Formply, the most common method of forming, is simply coated plywood and 2 x 4’s. Formply can vary in thicknesses and overlays. Thicker sheets with better overlays will offer a longer lifespan over thinner sheets with thinner overlays.

In this type of forming the sheets of plywood are generally cut on site to suit the needed size of panel. This offers a bit more flexibility when conditions are not as expected.

The forms are linked together with a series of walers (2x4’s), form ties and wedges. Holes for the ties all need to be drilled as per the specified spacing, which can vary by pour.

This type of forming is often selected, as it is the most economical for short-term use. However, the panels need to be often replaced, especially if not taken care of.

Please note that labour costs tend to be higher for formply systems as the initial set up time is extended by having to cut and drill the wood on site.

These systems are ideal for contractors who are not regularly forming, or for contractors that form uncommon shapes and sizes as they are more easily customized.

Please visit our Forming Systems page to browse your required concrete forming materials and products.

Forming Accessories You May Require

When it comes to concrete forming and reinforcement accessories, such as concrete reinforcing mesh, tire wire, and reinforcing chair, it can be hard to keep track of what each accessory does and is used for. That’s why we’ve outlined some of the most common accessories you may work with during your concrete forming project:

Rebar
Rebars are steel bars made of steel wires used as a tension device in reinforced concrete and reinforced masonry structures. Rebar strengthen the concrete and allow it to withstand greater forces than concrete that is reinforced with wire mesh. Typical use would include walls, roadways, and parking decks.

Support Chairs
Support Chairs are used in slabs for supporting all types of reinforcing steel. They are available in many different types of products such as continuous chair, slab bolster, wagon wheels, or linden chairs.

Continuous chair is made of steel, and the feet are dipped in rubber to prevent corrosion.

Slab bolster is available in plastic or steel versions, and are designed for thin slabs of concrete.

Wagon wheels are designed to be clipped onto mesh or rebar that will be placed vertically in forms.

Linden chairs are individual chairs that are made of plastic and are designed for thin to thick slabs where a corrosion free application is required.  

Tie Wire
Tie wire or wire loop ties are used to hold the reinforcing mesh or rebar together in proper placement to maximize the strengthening benefits of the reinforcement. Tie wire is available in rolls and can be cut to size as needed on site. Wire loop ties come pre-cut in bundles in specific lengths with loops on both ends to facilitate quick and easy tying application. Wire is tied using pliers or specially designed tying tools.

Formliner
Formliners are available for single use or multi use and can be used in many forming applications from precast and tilt up to pour in place. They line the concrete forms and create a pattern or texture on the surface of the concrete, creating an aesthetically appeasing finish on the concrete. Formliners are often used in civil applications such as underpasses or barrier walls.

Wire Mesh Sheets
Wire mesh sheets are an efficient, economical, and viable option for concrete reinforcement. They are ideal for driveways, sidewalks/walkways, or for any thin slab with light vehicular traffic. Mesh should be supported with slab bolster or linden chairs so that it forms into the middle of the concrete slab.

Form Release or Form Oil
Integral to any forming job; form release facilitates the clean and easy stripping of the forms from the concrete. It creates a film barrier between the concrete and the form, which makes removal easier, but it also protects the forms from the damaging affects of the water that seeps out from the concrete. It is available in many types from petroleum-based, to plant-based to water-based.

Concrete Vibrators
Concrete vibrators are designed to vibrate the concrete to expel trapped air within the concrete. The less air trapped inside the concrete, the stronger it is. Vibrators are available in internal and external configurations. Internal models have changeable head and shaft sizes so that they can be used for many different wall and slab sizes. External models are available with different motor sizes to suit different sized forming applications.

To see more forming accessories, please visit our Forming Accessories pages:

- Concrete Anchoring
- Precast Products
- Bridge & Roadwork

Contact NCA Today

With a full line of concrete forming products, including full concrete forming systems, concrete forming accessories, precast products, anchoring systems, bridge & road work products, and more, NCA is your one-stop shop for all things concrete forming.

Get in touch with us today by calling 1-888-777-9272.