Frequently Asked Questions

A void form acts as a reliable spacer to protect your structure from soil expansion. It’s important to use a reliable and redundant  product systems designed to create void space under structural concrete. It mitigates foundation settlement risk to help safeguard your project against costly damage.

Void forms are sacrificial formwork members designed to provide a space between the concrete foundation and expansive soil, i.e., to protect the foundation from the heave of the underlying soil.

There are two types of void formers- the removable type and the expendable formers. The removable void formers can obviously be reused time and again. The expendable types are designed to be left in place after the concrete has been cast. Reliable void forms (RVF) are expendable using molded pulp voids (MPV), offering the most affordable and dependable foundation for your project.

Material is a mixture of primarily blank newspaper and corrugated in a proprietary ratio. All materials are 100% recycled and are primarily post-industrial.

Reliable Void Forms are 24” x 24”, optimized for installer handling, shipping, storage and production cost. Since the RVF only weighs 3 lbs. each, installers can pick up several in a stack and drop them one at at time. The ground should support the form without sinking into the soil. The forms should not be exposed to moisture for more than 48 hours. If you have doubts, replace the forms quickly cover a large area.

They should support someone walking on them without deflection. You should not be able to compress the form with your hand. If a form weighs more than 4 pounds it should not be used. RVF can be used on damp soil, but NOT standing water. The ground should support the form without sinking into the soil.  The forms should not be exposed to moisture for more than 48 hours. If you have doubts, replace the forms.

RVF can be stacked to achieve a deeper void. Place the first layer as normal. Stack the second layer upside down so the forms are face to face with good stability. Put cover board on the top only, not in between the stacked forms. Then cover with vapor barrier taped securely at all joints. We recommend you start at the perimeter so that you do not have cut forms on the edge. Then work around the piers so that any cut forms are in the middle, away from edges.

Reliable Void Forms are stacked on 4×4 pallets, shrink wrapped for stability in transit and covered with a poly film pallet cover for job site storage protection. No costly storage trailers are in the way at the job and no back-haul charges for freight.

No. Experienced users should be able to install RVF quicker than carton forms. Customers like that RVF can be torn or cut to shape still hold their strength. No more complicated puzzle layouts, no cutting and taping carton forms with partitions hoping they won’t fail.

Preformed shapes are not necessary with Reliable Void Forms (RVF).  RVF can be cut to fit without losing the strength or moisture resistance.  You can cut a hole in the middle, remove a corner, or cut a shape to fit around a pipe or pier without worry. Construction foam is also a good way to fill small gaps if you prefer not to cut forms.

Yes, this system works well when placed are ok to use: monolithic. It is not necessary but some customers have poured a thin mud seal over the covered Reliable Void Forms in the beams for protection and to form a soil retainer while they prep the slab and then place the foundation.

Just like with carton forms, a good vapor barrier with taped joints is all that is required.  Some customers also chose to tape the hardboard panels.