FORMrite®

FORMrite is a high quality overlaid panel produced predominantly from graded Pinus radiata veneers. These are glued with phenol formaldehyde resin and overlaid with a hard durable resin impregnated paper to give concrete a smooth finish. With a durable A-Type Marine bond, FORMrite can withstand the rigours of construction moisture. Its hard phenolic surface and high quality outer veneers make it durable and reusable.

FORMrite gives builders a better surface for pouring concrete and offers a class 2 finish on the first pour (when used in accordance with the recommended Carter Holt Harvey fixing details). FORMrite is a cost effective solution;

• Significant number of re-uses.
• Can be used in modern optimised form systems such as table forms.
• Suits a range of frame spacings, concrete pressures and surface tolerances.
• Can be used on steel or timber form frame systems.
• Lighter in weight than imported or rain forest hardwoods.

FORMrite has a cross-laminated construction. So the panel is less likely to expand or contract when exposed to rain and temperature changes, making it easier to lay forms for large decks. It's worth remembering that excessive moisture can cause panels to swell, move and stiffen.

Identification & Codes

Design is usually deflection-controlled using standard engineering techniques according to the Australian and New Zealand codes and the section properties above.

Understanding Codes

For example, 17-10-7 is a 17mm thick panel with a 1.0mm face veneer and 7 plies. Note how different the properties of the two 17mm panels in Table 2 are when laid in different directions to the supports. Make sure you identify and use the correct one for a given design.

Framing and plywood thickness

Framing centres depend on the identification code and the direction of the face grain for a given pressure of wet concrete, and the design limit decided by the designer.

Table 2: Pressures

These are the allowable concrete pressures for FORMrite, continuously supported over three spans.

Allowable concrete pressures for different frame centres and a deflection limit of plywood span/270 or 3mm max are in Table 2 based on the use of F11 stress grade. Allowable pressures for F14, F17 and F22 stress grade FORMrite can be obtained by multiplying Table 2 values by 1.14, 1.33 and 1.5 respectively. In New Zealand, only F11 is regularly available.

Sheet layout

Lay sheets with the face grain (long edge) across the framing. Allow a 2 to 3mm expansion gap on all sheet edges. Use polystyrene filler or joint sealer in the expansion gaps if required.

Tips:

1. Used with proper release agents, edge and face tapes and solid perimeter fixing, Hardwood faced formply can achieve a Class 2 finish. Class 2 finish can only be achieved on one pour per face as the condition of the face after the first pour is out of our control.
2. It is a mandatory requirement of AS3610 to provide test panels if a Class 2 finish has been specified.
3. Allow for expansion and contraction of the panels to avoid possible buckling. Moisture uptake can increase the dimensions of the panel and an expansion gap of approximately 2mm is recommended.
4. Recommended fixing is with 50x2.8 or 60x2.8 nails for 17mm thick FORMrite. See Table 3 for fasteners. The practice of 4 nails in each corner does prevent uplift and sliding, however cannot be totally relied on for all classes of finish.
5. Hardwood faced formply provides a tighter colour and surface consistency and the number of re-uses is generally increased.
6. If the above recommendations are not adopted, a maximum of Class 3 can only be achieved.

Fasteners

Table 3: Fasteners

Here are the minimum recommended fastener sizes for use in timber or steel frames.

For load information, consult the Carter Holt Harvey Plyfloor brochure and NZS 3603 or AS 1720.1 for further information. Use flathead nails or countersunk screws. Other specialty formwork fasteners may be used subject to performance.

• In timber framing, helical thread or longer nails can provide additional withdrawal resistance.
• In steel, shorter screws can be used provided the thread penetrates the steel fully (after fixing). Screwed joints between plywood and thicker steel are very stiff and small differential movement caused by construction moisture can generate excessive screw loads if the screws are too small.
• Fasten at 150 mm centres on edges and 300 mm centres on intermediate framing, or use proprietary formwork seating and fastening systems.
• To avoid staining of concrete if forms are used often, use hot dip galvanised, stainless steel or alloy nails or screws as required.

Release agents

Apply sparingly. Heavy application may cause runs and colour variation in the concrete.

Compliance

FORMrite is reliable, PAA (Plywood Association of Australia) quality tested plywood carrying the PAA quality stamp - your guarantee of performance. FORMrite can be used in compliance with the Building Code of Australia and the New Zealand Building Code as follows:

Structure

FORMrite is structural plywood manufactured to AS/NZS 2269 which is included in the timber engineering codes in Australia and New Zealand. FORMrite can be designed using AS 1720 Timber Structures Code or NZS 3603 Timber Structures Standard. Other components such as studs, walings, props, bearers etc should be designed using the relevant codes for timber or steel as appropriate.

Specifications

Surface overlay:

45/130 gsm phenolic impregnated paper.

Edge sealant:

Specially formulated to retard water penetration.

Glue bond:

Type A bond. Phenol formaldehyde.

Dimensions:

Sheet size (mm) 2400 x 1200 and (mm) 1800 x 1200. Tolerance +/- 4%.

*Tolerance: As per AS/NZS 2269
**Tolerance: +/- 2%

Storage, handling and maintenance

• For best durability and longest re-use potential:
• Store under ventilated cover.
• Handle and stack with care to avoid damage.
• Stack flat clear of ground on at least three evenly spaced bearers.
• Re-seal cut edges with acrylic paint.

Limitations

All statements in this manual shall be read subject to the plywood being properly stored, handled, installed, used and maintained as appropriate to each application in accordance with this brochure, and subject to the governing codes of practice.