In modern construction, laminated plywood for formwork has become actively used. It is suitable for the construction of various types of bases. Its service life is quite high, since the surface is protected from moisture by a special coating. The highest quality products are able to withstand up to 50 cycles of use without significant deformation changes.
General Product Information
Laminated plywood for formwork is produced from wood that has undergone a pressing process. The individual layers are bonded to each other with a resin-based adhesive. Acrylic varnish is applied to the ends of the boards to provide protection against moisture. A film of sufficient density is superimposed on top. Manufacturing technology involves exposure through high temperatures and a certain pressure.
Benefits of Using Material
Since plywood laminated for formwork has good moisture resistance and sufficient strength characteristics corresponding to the GOST clauses, its operational period is quite long. The phenolic film on the surface protects the material from ultraviolet radiation.
Sheets are easy to cut even when working with hand tools. As fasteners, studs, nails or self-tapping screws can be used. Due to the presence of a special film, the concrete composition does not stick to the surface of the slabs.
Qualification classification
Depending on the grade, laminated formwork plywood can have a different cost. Each category allows for certain flaws. There are four types of products:
- Defects are completely absent.
- There are wormholes and fused knots that are covered with veneer inserts.
- There are holes and hollows.
- The surface contains a large number of various defects.
The quality of the boards with the improvement of grade is improving. Their strength is also getting better, which has a positive effect on the service life. Products without knots and wormholes will in any case last longer.
Laminated plywood for formwork: sheet sizes
When pouring foundations, slabs with a thickness of 18 mm are most often used, since their strength is quite high and the price is quite reasonable. As for the width and length, sheets of sizes 300x150, 250x125 and 244x122 cm are more widely used.
Some manufacturers produce products of other dimensions, but they are rarely used to form formwork. All presented standard sizes of the same brand do not differ in operational characteristics or physical properties.
Bearing elements of the frame
Before the laminated plywood for formwork is installed, a support structure capable of withstanding the concrete composition must be erected. Typically, a metal profile system may include:
- linear panels having approximately the same dimensions as the sheathing sheets;
- corner elements used for installation on the edges of the frame;
- universal barriers for creating columns;
- telescopic racks equipped with a holder for forming floors.
If necessary, wooden blocks of a suitable cross section can be used to arrange the frame base. However, with regular work associated with the construction of foundations, it is better to purchase special metal shields.
Laminated product turnover
Data on the use of various materials are almost always contradictory. However, it should be said that the turnover of formwork from laminated plywood can reach 50 cycles, which is considered a pretty good result. This is possible if products from European manufacturers were purchased.
As for the Russian market for such products, it is represented by a large number of brands. However, their quality characteristics are inferior to analogues from Europe. Typically, domestic products can withstand no more than 20 cycles of use in standard conditions.
Sometimes cheap laminated plywood for formwork is used. China is its main supplier. In most cases, such products become unsuitable for further use after 5 cycles. However, with careless operation, the service life of the material is significantly reduced, regardless of manufacturer.
In conclusion about the features of care
When installed , plywood laminated for formwork exposes to building mixtures containing a certain amount of water, abrasive substances and active additives. If the coating is able to withstand the listed external factors, then the inside is not. The main danger lies in damage to the laminated surface, as it opens a channel for absorbing moisture.
Destruction of the protective layer can be avoided by careful handling of products during installation work. After removing the sheets should be timely cleaning of the surface from contamination. Before long-term storage of the plate, it is advisable to lubricate with special means. This will improve the water repellent ability.
Accurate installation of the material requires workers only to observe normal labor discipline. Plywood sheets must be laid on the prepared surface without protruding nails and other sharp-pointed parts. When installing fasteners, damage to the coating should be avoided.