← Back to Solutions

What is Void Formwork?

Void formwork is a structure made of recycled plastic that shapes concrete and stays inside the finished slab. It is used to raise a floor without filling the space underneath with heavy material — instead of pouring solid concrete, compacting soil or laying EPS blocks, the void formwork pods create a strong, permanent void that only needs a thin 5 cm concrete topping on top.

The result is a raised floor (up to 300 cm) that is dramatically lighter, faster to build and cheaper than conventional fill methods. Because the system is single-use by design, nothing needs to be stripped or removed after the pour — the pods simply stay in the slab.

In the Philippines, ABS Void Formworks are the best option for slab-on-grade and renovation applications — sunken slab fills, landscape fills, amenity floors, car park ramps, swimming pool decks and fills between foundation footings. Two systems cover every height: ABS Plus (adjustable, 20–300 cm) and ABS Level (fixed, 5/10/15 cm).

Why builders choose void formwork

How it works

The pods click together on the formwork, rebar is laid across the pod tops, a thin 5 cm topping slab is poured, and the pods stay inside the slab permanently — nothing to remove.

Common questions about void formwork

What is void formwork?

Void formwork is a concrete-shaping structure made of recycled plastic that is used once and stays permanently inside the slab. Also called disposable or permanent formwork, it creates reinforced concrete raised floors up to 300 cm — a lighter, faster and more economical alternative to filling the void with soil, EPS or solid concrete.

How does void formwork reduce concrete usage?

Instead of filling the whole raised area with concrete, void formwork displaces the volume with air. Only a thin topping slab (5 cm) plus the 2 cm pod legs — about 7 cm of concrete in total — is needed. At 100 cm fill height that is roughly 93% less concrete than a solid fill, cutting weight on the structure and material cost.

Is void formwork suitable for high-rise buildings?

Yes. ABS Void Formworks have been used in Philippine high-rise projects including The Seasons Residences by Federal Land and The Yuchengco Centre. Because the system removes hundreds of tonnes of dead load from the structure, it is especially valuable on upper floors, roof decks and transfer levels of tall buildings.

How fast can void formwork be installed?

ABS Level installs at up to 100 m² per hour and ABS Plus at about 20 m² per hour — with no skilled labor required. The pods simply click together on the formwork, rebar is laid on top, and concrete is poured. This speed shortens the construction schedule compared to soil compaction or EPS placement.

How does void formwork reduce construction costs?

Costs drop on several fronts at once: far less concrete to buy and pump, no soil import or export, up to 50 fewer truckloads per project (one truck of ABS replaces up to 50 trucks of fill), and a faster schedule that reduces labor and site overhead.

What materials are ABS Void Formworks made from?

ABS Void Formworks are made from 100% recycled polypropylene (PP). The material is single-use by design and stays inside the finished slab, so nothing is removed after the pour. The recycled content also contributes to LEED points on green building projects.

What is the difference between ABS Plus and ABS Level?

ABS Plus is adjustable and covers fill heights from 20 cm to 300 cm, making it the choice for deep fills and structural slabs. ABS Level is a fixed-height system for the most common shallow fills — 5 cm, 10 cm and 15 cm — and installs the fastest.

Can void formwork be used for slab-on-grade and renovation work?

Yes — in the Philippine market this is where ABS Void Formworks perform best. Typical applications include sunken slab fills, landscape fills, amenity floors, car park ramps, swimming pool decks, and fills between foundation footings, both in new construction and renovation.

What is the load-bearing capacity of ABS Void Formwork?

The standard system carries a 55 kN/m² live load at 100 cm fill height with just a 5 cm topping slab. For heavy-duty applications such as truck ramps, the Wide Base System provides extra support at the base of each pod.

Is void formwork environmentally friendly?

Yes. It is made from 100% recycled polypropylene, dramatically reduces concrete and cement use (one of the largest sources of CO₂ in construction), cuts truck movements on site, and supports LEED certification points.