The main expectations of customers from this plywood are that it should be durable in alternate wetting and drying conditions, should have a hard surface and should have sufficient strength to withstand the weight of concrete and forces caused by concrete pouring and vibrations.
Shuttering plywood for concrete shuttering works is a special product, chemically treated by the manufacturer to suit its intended use so that it can withstand any kind of fungal and microbial attack during use. Particularly suitable for use in concrete shuttering and formwork. Concrete shuttering plywood is very economical as it can be used again and again depending upon the care taken during construction. The main expectations of customers from this plywood are that it should be durable in alternate wetting and drying conditions, should have a hard surface and should have sufficient strength to withstand the weight of concrete and forces caused by concrete pouring and vibrations.
The Bureau of Indian Standards has given the following instructions to the manufacturers for shuttering plywood under IS 4990:2024.
1. Only BWP
Only BWP resins conforming to IS 848 should be used in shuttering plywood. At present, the use of MR and BWR grades is prohibited for making shuttering plywood. Therefore, material made from commercial resins is completely against ISI norms.
2. Shuttering plywood is now mainly divided into three Shuttering plywood is now mainly divided into three types as per the standards given by Indian Standards:
Type 1 – Plywood for Concrete Shuttering Works (Plain) – C.S.
This shuttering plywood is designed for use in areas where the customer does not require high repetition during construction. In fact, it looks similar to normal plywood made from BWP grade resin, however it is given 12 kg/m3 chemical treatment during manufacturing. Generally, this plywood is considered suitable for 5 to 6 repetitions. However, its presence in the market is negligible due to lack of awareness.
Type 2 – Plywood for Concrete Shuttering Works with Plastic Coating (Coated) – C.S.C.
Where the customer feels the need for some more repetitions of the plywood, a plastic layer is applied on both sides over base ply i.e. Type 1 and is provided by the manufacturer. This shuttering plywood is designed for use in areas with high repetitions use but because of awareness this product is also not available in the Indian market. The repeatability of this plywood depends upon the thickness and stiffness of the plastic coating applied on the plywood.
Type 3 – Plywood with Overlay (Film Face) Suitable for Concrete Shuttering Works – CSFF
This form of shuttering plywood is very commonly seen throughout India. In this product, Type 1 is used as base ply and paper film treated with phenolic resin is applied on both sides by hot and cold pressing process and this film makes the plywood suitable for maximum repetitive use. Normally the repeatability of use of this material can be from 10 times to 50 times.
Use of Preservatives in Shuttering Plywood
In compliance with the standards of Bureau of Indian Standards, manufacturers use mainly two types of treatments in shuttering plywood.
1. Copper-chrome-boron (CCB)
2. Acid-copper-chrome (ACC)
This preservative composition is injected inside the plywood by using a special type of machinery pressure treatment plant and in no case the quantity of this preservative chemical in shuttering plywood should not be less than 12 kg/m3.
The currently available specification IS 4990 has given special attention to the formaldehyde emission standard in plywood keeping in mind the interests of the customers and 0-8 mg/100 gram has been kept under E1 standard and 8-30 mg/100 gram has been kept under E2 standard.
As you all know, in the last few years a new market of shuttering plywood ranging from 24 kg to 28 kg has developed in our market. You will be surprised to know that the market of this type of material is around 40% of the total market. According to information, about 250 institutes in the country are producing shuttering plywood, which means that more than a hundred units are launching such products in the market. The problem is that this type of shuttering plywood which is made of MR (commercial) resin and which also has the seal of IS 4990 is completely in violation of the rules of the Bureau of Indian Standards. Therefore, the Quality Control Order which will be fully implemented in August 2025 will create a big crisis for all these industries. As you know, shuttering plywood is not an ordinary plywood, it is also a matter related to the safety of hundreds of workers working on the construction site. Therefore, through this article, I would like to request everyone to please manufacture shuttering plywood in their respective units only and only as per IS standards and use the BIS seal only on those malls which are fully compliant with these standards. You can use Type 1 CS for customers with low repute.
I would like to thank the Ply Reporter team for giving me this opportunity to write and being the General Secretary of the Wood Technologist Association, I would like to put forward the following suggestions to you:
1. BWR grade should be added to shuttering plywood so that the manufacturers of our MR grade material can add a little cost to sell phenolic plywood in the market and MR grade shuttering plywood should be completely banned. Due to dilution of standards of plywood products, many of our products have almost disappeared from the market in the past like chequered plywood, truck flooring, fire retardant plywood etc.
2. As per the requirement of the customer, shuttering plywood should be divided into two parts, first nondensified (0.62-0.80 gm/cm3) and densified (0.80-1.02 gm/cm3). As you know that densified plywood generally does not require any type of chemical treatment (refer to IS 3513), hence the requirement of 12 kg/m3 should be removed from shuttering plywood having density/weight of 0.80 gm/cm3 (28 kg and above) or more.
3. Apart from the pressure treatment process, soaking method (Dipping process) and glue line poisoning (GLP) should also be added in shuttering plywood so that it can be easily integrated with the day-to-day activities of the industry.
Customer awareness gives an opportunity to our manufacturers to do something new and innovative, so keep in mind the usage requirements and formaldehyde emission level of your construction site before buying shuttering plywood in future.
[Published in Ply Reporter's May 2025 Print Issue]