How to Store and Stack Precast Concrete Fence Panels

Store precast concrete fence panels on firm, level ground, on two clean dunnage supports that line up vertically through the stack, and only after each panel has reached stripping strength and passed inspection. The NPCA Quality Control Manual for Precast Concrete Plants requires storage that avoids uneven bearing, badly placed dunnage and stacks built too high, and a PCI plant quality talk on yarding and dunnage is blunt that poor yard storage turns into damaged product or considerable field repairs.

When is a fence panel ready to leave the mold?

A fence panel is ready to leave the mold when its concrete has reached the stripping strength your plant QC manual sets for that product, not when a fixed number of hours has passed. The NPCA manual requires a product-specific minimum stripping strength and one-day or stripping strength tests for each mix design at least quarterly, and PCI's cylinder guidance averages two breaks before a piece is released. That number belongs to your mix and your cure, which is why it lives in your own manual.

The temperature step matters too. NPCA limits the change in ambient temperature around curing product to 40°F per hour, which counts when panels move from a covered curing area into an open yard. Our hot weather casting guide covers the summer side of that problem.

Inspect before you stack. NPCA requires a documented post-pour inspection of 1 piece or 3%, whichever is greater, of each product, looking for damage, excessive bugholes or honeycombing, dimensional problems and exposed reinforcing. Each inspected panel gets a mark reading acceptable, needs repair or rejected, and the records are kept for three years.

How should you lift panels out of the mold and across the yard?

Lift panels with inserts and rigging rated well above the panel's weight, and with nobody underneath. OSHA 29 CFR 1926.704 requires lifting inserts embedded in precast members to support at least four times the maximum intended load, and lifting hardware such as slings, chains and hooks at least five times. The same section keeps workers out from under members being lifted, and NPCA's plant layout rules say to avoid stripping or lifting products over personnel or equipment.

The first lift out of the mold carries extra load. NPCA tells plants to size lifting inserts for form release suction and impact as well as the weight of the product. Commercial inserts and hardware need their capacity posted and an inspection or certification no more than one year old, and NPCA's commentary asks operators to check handling equipment daily.

Where should the dunnage go under a stacked panel?

Dunnage under a stacked panel belongs at two points, near one-fifth of the panel length from each end, lined up vertically from the top panel to the ground. PCI's yarding guidance calls for two dunnage points unless the design requires more, and NPCA's technical services team puts the ideal location for a uniformly loaded slab at about L/5 from each edge, where bending in the slab is smallest and balanced. A fence panel stored flat behaves like that slab, but if the panel's designer specified other support points, use theirs.

Alignment carries the stack. NPCA warns that an offset between layers creates shear and bending in the panel caught between them, so each layer's dunnage should sit directly over the layer below. NPCA also recommends dunnage as wide as the product, and its plant standard asks for bearing surfaces large enough to keep edges from chipping.

A stack is only as sound as the ground under it. PCI wants flat ground that is paved or graveled and regraded as traffic and weather wear it down, and NPCA says to deal with small puddles before they soften the subgrade. Neither body publishes a universal stack height, so set a limit per product in your QC manual that the bottom panel and the pad can carry without the stack leaning.

What goes wrong in a fence panel yard?

Most yard damage traces back to the dunnage or the ground, and PCI's list of common issues reads like a walk through a busy casting yard.

Problem	What it does	Fix
Dunnage out of line between layers	Shear and bending in the panel between supports (NPCA)	Stack each layer directly over the one below
Soft or uneven ground	The stack settles and racks (NPCA, PCI)	A paved or graveled pad, regraded as needed
Dirty or sappy timber	Stains from sap and water runoff (PCI)	Clean dunnage that leaves no marks
Sharp edges at supports or forks	Point loads that spall edges (NPCA)	Rounded or chamfered edges at support points
Poor-quality dunnage	Cracked product (PCI)	Retire damaged dunnage

Staining costs more on a decorative panel than on a utility product, because the textured face is what the customer is paying for. Elastoquip's mold systems put texture on both faces of the panel, so both faces need protecting in the stack. NPCA also notes that synthetic fibers can help reduce chipping of stripped products, though they add no compressive strength.

Should the yard hold anything that is not ready to ship?

The storage yard should hold only product that is ready to ship. NPCA's commentary recommends it because every extra move is another chance for damage, and repairs are done better in a designated area than out in the yard. Minor defects that do not affect function or service life can be repaired by any method that does not impair the product; major defects must be repaired or the product rejected, and rejects are marked and stored apart from good stock.

The QC inspector walks the storage area and the stored product daily, and shipment records, including anything damaged on delivery, are kept for at least a year. Plan the pad around output as well: our guide to how many panels a gang mold can produce is a good starting point for sizing the storage area and the dunnage stock that goes with it.