Principles to minimise potential problems with Class2 and Class 3 off form Surface FinishesPrinciple One: Most issues with off form surface finishes are associated with moisture.Wherever possible protect the formwork from weather. This includestarping where practical.Principle Two: The phenolic surface film used on formwork plywood is not impermeableto moisture. To ensure that moisture penetration is minimised, releaseagent and form oils …

Grain Raising or Surface SwellingGrain raising is caused by moisture penetrating the phenolic surface film and causingswelling of the surface veneer.The causes of grain raising are: Severe weather exposureFailure to use release agent or form oilDamage to the phenolic surface film i.e. misuse of vibrators, handling damageetc.Faulty phenolic surface filmAs mentioned previously, the purpose of the phenolic surface film is …

Staining in FormplyThe most common stains associated with formply are: Rust stainingTannin stainingPinking – free phenol from the phenolic surface film.In the writer’s experience, most staining is due to rust deposits on the deck at the time ofpouring or iron in the aggregate. These stains appear red/brown and are often mistakenfor tannin staining.Tannin staining is the result of extractives from …

Do not use any new panels showing bow or twist out of the pack. Wheredistortion exceeds 30mm, these panels fail the product standard. They shouldnot be used and returned to the manufacturer.Prevent/Minimise Exposure to MoistureWhere formply panels that have been supplied flat on site distort, there is onlyone cause, this is exposure to moisture, or a change in moisture content.6No …

Wrap and Twist in FormplyAS 6669 provides a 30mm flatness limitation for formply sheets. To measure flatness,formply sheets are placed concave down on a flat surface and any bow or twist exceeding30mm above the flat fails the product Standard.In addition, sheets must be able to be pushed flat using “palm pressure”, of approximately15kg.Formwork plywood supplied to the market with flatness …

This technical note has been developed in response to market problems and failuresrelating to the quality of off form finishes being achieved from formwork plywood in theAustralian market.Most issues relate to Class 2 surface finishes as defined in AS 3610, but issues do from timeto time occur in Class 3.This Technical Note discusses some common formwork plywood problems and lists …

Choosing your Plywood Formply is typically covered with an overlay paper to slow water absorption andcreate a smooth concrete surface; however, there are many different types ofplywood overlays and not all of them are suitable for use on formply. AS6669 hasstrict requirements for the quality of formply overlay to ensure it is water resistant,durable and will not adhere to the …

For years, judging the quality of the as-cast concrete was really a guessing game. Often “good enough” translated to “only a few bugholes” and walls that weren’t too curvy. The subcontractors who followed the concrete placement were expected to patch any honeycombed areas and adjust their framing work to the dimensions left after formwork removal.  But in the last few …

Clean and apply release agents. Soon after removal, plywood forms should be inspected for wear, cleaned, and repaired, spot-primed, refinished

Timber Products is one of the world’s largest processors of hardwood veneer. Each sheet of veneer that is used for the company’s hardwood plywood panels is inspected and graded by veteran graders who average more than 10 years of experience. The result is consistent, quality veneers that meet the unique needs of each customer. As attractive as it is versatile, …