In the wet and rainy season, the construction site of gypsum board installation will always encounter the problem of gypsum board wave, and how to batch putty is also uneven, on the contrary, the more batch wave is bigger, exactly why? How can it be prevented? Here is a brief analysis:
One of the reasons: the sealing direction of gypsum board is not correct. 99% of the wave cases are caused by the direction of the sealing plate. Because 80% of the strength of the gypsum board comes from the face paper, and the fiber layout of the paper is directional because of the influence of the production process, which also determines that there is a very big difference between the longitudinal and transverse strength of the gypsum board. Generally, the longitudinal strength is three times of the transverse strength.
Therefore, when installing gypsum board ceiling, we must make full use of the longitudinal strength of gypsum board, and require the length direction of gypsum board and the direction of auxiliary keel to be installed vertically.
The second reason: the construction site is too wet.
Ordinary gypsum board can be used in the environment below 90% relative humidity, but in Meiyu season or some basement places, the humidity of the site environment often exceeds 90% for a long time, which leads to the gypsum board inhale too much moisture, increase the weight of the gypsum board, reduce the strength of the gypsum board, and finally lead to the gypsum board wave.
Solution: to improve the construction site environment, use 12mm water-resistant gypsum board, and brush sealing primer on the board surface.
The third reason: using old powder (double fly powder) to make full batch of putty.
As we all know, it usually takes one day to make a full batch with old powder. If the weather is humid, it may take two days or even a week. Old powder belongs to air drying products, its drying speed is affected by the humidity and temperature of the environment, and the old powder itself absorbs moisture very seriously. If this kind of putty is applied to the gypsum board, on the one hand, it will continuously increase the weight of the gypsum board; on the other hand, it will continuously transport the moisture in the putty to the gypsum board, resulting in the decrease of the strength of the gypsum board. As a result, the board will deform as time goes on.
Solution: full batch gypsum products (chemical drying, drying speed is generally 90 minutes, not affected by air humidity and problems).
