Experts tell me, what is the general thickness of polyurethane exterior wall spray paint?

The current standard for the thickness of polyurethane exterior wall spray paint stipulates that the thickness of polyurethane waterproof coating is 2mm. This thickness is only 1/3 of the width of the test sample (the width of the sample in the test is equivalent to the thickness under engineering use) ). Due to the unevenness of coating construction, the thickness of 2mm should be understood as the value at the thinnest point, which requires a dosage of more than 2.5?kg/m2.

The thickness of polyurethane exterior wall spray paint can be obtained from the following steps:

1. Scrape and level. (801 glue and white cement. Fill the slotted position.)

2. The first putty layer. (No one will polish and then apply the second and third putty. Experiments have proved that when the first putty is polished and then the second putty is applied, due to the smoothness of the surface. The adhesion between the second putty and the first putty Obviously, it will definitely fall off layer by layer in the future. This is known to anyone with real construction experience on site)

3. The second layer of putty. Apply the second layer of putty after the first layer is dry, and then polish it smooth using 240# or 280# water-based sandpaper and lighting.

4. Before applying primer, use a 2-meter-long aluminum alloy strip to test the flatness of the wall. It should be repaired and smoothed before applying primer.

5. After the primer is applied, you should check again at this time, because the primer will react with the putty, and small holes will appear in the wall. Make repairs at this time.

6. The last step is topcoat. The total thickness is about 5mm. The thicker it is, the easier it is to crack. No one will scrape off the third coat of putty, if it is really the third coat of putty. In this way there will be four layers, including the base leveling layer. This will greatly increase the likelihood of cracking in the future. Anyone who really understands construction understands this. The more you scrape, the better. The more you scrape, the faster it will crack.