Steps to paint the exterior wall How to paint the exterior wall?

Painting buildings with exterior wall paint can not only beautify the appearance, but also play a protective role. So there are many ways to paint the exterior wall now. So, how to paint the interior and exterior walls? What are the specific construction steps?

Although painting is simple, there are still steps to follow to ensure the quality.

1, construction preparation

① Requirements for base materials: the plastering of the base course has been completed and maintained for about 20 days, the alkaline PH value of the base course is below 9, the base course has been dried (at least 15 days) and the humidity is below 8%; The surface of the grass-roots level is smooth, the angle of yin and yang is dense and distinct; There are no structural problems such as water seepage, cracks, hollowing and bubbles on the wall surface. No loose powder, no oil, grease and other adhesion.

(2) Waterproof and airtight treatment has been made for the reserved joints of external walls.

(3) The paint used has the factory certificate and meets the requirements of relevant national codes and standards through inspection.

(4) The paint used is approved by the owner, and the model wall is approved by the owner, supervisor and design unit.

⑤ Decorative scaffolding has been set up.

⑥ Exposed iron parts at the grass-roots level have been properly rusted.

⑦ Construction conditions: The temperature required for construction and maintenance is higher than 5℃.

The ambient humidity is lower than 85% to ensure good film formation. Weather factors must be considered in the construction of external walls. It doesn't rain 12 hours before painting, so as to ensure that the base is dry. It can't rain for 24 hours after painting to avoid the paint film being washed away by rain. 2, exterior wall coating construction method

The coating system of exterior wall architectural coatings is divided into three layers, namely primer, first layer and second layer. The construction technology is as follows:

Repair → cleaning → putty filling and partial putty scraping → screeding → sticking glass fiber cloth → full putty scraping → screeding → primer construction → first coating construction → second coating construction.

First, repair

Before painting, use 1: 3 cement mortar (or polymer cement mortar) to repair the defects such as lack of edges and corners and holes in the matrix. Specific practices:

Empty drum-if it is a large area of empty drum (greater than 10cm2), all the empty drum parts should be removed and re-made as the base; If it is a local empty drum (less than 10cm2), low viscosity epoxy resin should be injected to repair it.

Cracks-tiny cracks should be repaired with putty (thin batch is required when repairing, not thick brush).

After drying, smooth it with sandpaper; For larger cracks, the cracks can be chiseled into V-shaped cracks, cleaned and made into waterproof layer, then embedded with 1: 2.5 cement mortar, dried and polished with cement sandpaper. Hole-3 mm below the base surface? The following holes shall be leveled with polymer cement putty, and holes larger than 3mm shall be repaired with cement mortar, dried and polished.

In addition, for the new cement mortar surface layer, if it is urgently needed to be painted, zinc sulfate or zinc oxide solution with the concentration of 15%-20% can be painted on the surface of the cement mortar base for several times, and the powder and floating sand deposited on the surface can be removed after drying.

B, cleaning

Dust and powder can be washed with broom, brush and high-pressure water; Grease, washed with neutral detergent; Mortar, shovel, scraper, etc. ; Mould; Rinse with outdoor high-pressure water, rinse with clean water and dry.

C, putty, local blow be bored with child.

If the wall is flat and smooth, you don't need putty; Putty should have good strength and durability besides being easy to scrape and polish. In the construction of joint filling and local putty scraping, thin batch is required instead of thick brush. Putty is required to have good cohesiveness, durability and water resistance. The putty used is a mixture of 107 white cement slurry and 159d-20M fine sand.

Needless to say, this seemingly simple process of painting actually contains a lot of technical content, otherwise even if it is painted on the wall, it may not get the desired effect.