The exterior wall paint is like the neon clothes of the building, which not only adds luster to the project, but also protects the building itself
Exterior wall coating is a matter of high concern to customers, so in terms of cost control, we must have a more in-depth understanding of the relevant knowledge of exterior wall coatings in order to spend the money on the knife.
Today, I will share with you the key points of cost optimization management and control for exterior wall coatings.
Classification of exterior wall coatings
Exterior wall paint is an engineering material that is coated on the surface of a building, can be dried and cured into a film, and has a decoration, protection and special function for the coated object.
The classification of exterior wall coatings on the market is rather chaotic.
The main reason is that coating manufacturers give different names to their products.
However, the more customary classifications in the industry can be roughly divided into three categories: elastic coatings, texture coatings, and imitation stone coatings.
See the table below
Cost analysis of exterior wall coatings
The paint is generally composed of putty, primer, middle paint and top paint.
Let's take a look at the price of several coatings
Through the analysis of the unit price composition of exterior wall coatings, the main factors affecting the cost of coatings are: materials, construction techniques, coating rates, construction methods, etc.
The cost optimization control point of exterior wall coatings
The main factors affecting the cost of exterior wall coatings are analyzed above.
Materials, construction technology, building shape and base level conditions, we will introduce the control matters of cost optimization from these aspects.
Cost analysis of exterior wall coating materials
1 Raw materials
Emulsion (commonly used styrene acrylic, pure acrylic and silicone acrylic) is the main component of exterior wall coatings, which has the functions of bonding, weather resistance, sealing, and alkali resistance;
Generally, styrene-acrylic emulsion is about 7.
9 yuan/L (which can meet the requirements of primer), pure acrylic is about 10.
4 yuan/L, and silicon-acrylic is about 13.
3 yuan/L; therefore, the choice of emulsion affects the cost of com" href="">coatings.
For exterior wall coatings of a project, the primer coating rate is 10M2/L.
If styrene-acrylic emulsion is used instead of pure acrylic emulsion, the cost will be reduced by 0.
The exterior wall of a project is made of real stone paint, and the coating rate of the medium paint is 0.
If pure acrylic emulsion is used instead of silicone acrylic emulsion, the cost will be reduced by 13 yuan/m2
Therefore, when choosing exterior wall coating materials, the cost relationship is:
Silicone Acrylic Emulsion＞Pure Acrylic Emulsion＞Styrene Acrylic Emulsion
2 Paint material
At present, the commonly used coating materials on the market are divided into elastic coatings, texture coatings and imitation stone coatings (the name of each company will be different)
Elastic coating is a form of application of pure paint material
Texture paint is a form of paint that contains sand particles in the paint
Imitation stone paint is a paint containing rock flakes
The cost relationship between the three is: elastic coating <texture coating <imitation stone coating
For high-level businesses, due to their visibility, the visual effects of various coatings are not very different.
It is recommended to use stone-like coatings with caution.
Analysis of construction process cost
1 Elastic coating
The common construction techniques of elastic coatings include flat coating and etched.
From the difficulty of construction to the degree of material loss, flat coating is cheaper than etched.
Here we will focus on the garland process.
The garland effect plays a decorative role.
The garland is divided into small garland, medium garland and large garland.
The price is about (28, 33, 37) yuan/m2 respectively, and the pattern is made.
Optimizing is to ensure that the effect is not significant, and it is one of the ways to effectively control costs
At a certain distance, the effect of large flowers is not obvious compared with that of medium flowers.
Small flowers have a little advantage in price.
It is recommended to choose medium flowers or small flowers first.
2 Texture coating
The sandy surface layer of texture coating plays the role of abrasion resistance, weather resistance, and texture effect.
Therefore, optimizing the selection is the main way to balance the effect and the cost.
Fine sand is around 33 yuan/m2, medium sand is around 38 yuan/m2, and coarse sand is around 50 yuan/m2.
Among them, the cost advantage of fine sand is obvious, and it can also show the texture effect well.
It is recommended to choose the best;
From the cost point of view, the effect of medium sand and coarse sand is not much different, but the cost difference is large.
It is recommended that medium sand be preferentially selected between medium sand and coarse sand.
3 Imitation stone coating
Imitation stone paint is used to imitate the effect of exterior wall stone, so it is also called liquid stone.
It is a one-component paint for building exterior walls that is made up of two or more water-based color particles suspended in a water-based interlayer and produces multiple colors by spraying at one time.
It is based on acrylic resin emulsion and elastic resin solution.
The base material, through the reasonable ratio and color matching of white quartz sand and artificially calcined colored sand, sprayed with high-pressure spray gun, showing a rich imitation stone coating
The biggest difference between imitation stone paint and ordinary paint is that there are rock fragments in the imitation stone coating, or the imitation rock fragments formed by the colored paint after drying and knotting.
Theoretically, the more rock fragments, the more expensive, the more expensive the rock fragments, the more expensive the coating
In addition, the price of imitation stone paint is also related to its color retention.
The lower the color retention (the lighter the color), the higher the price.
Cost analysis of coating rate
Theoretical coating rate The theoretical coating rate refers to the coating applied on a smooth surface without loss, the area that can be coated per 1L is m2, and the unit is m2/L.
Due to different uses, the dry film thickness of the coating can be changed, so its theoretical coating rate will also be changed accordingly
Actual coating rate The actual coating rate will be affected by various factors and vary.
Such as the construction method, the skill of the worker, the structure and shape of the coated object, the surface roughness, the working environment and the distribution degree of the paint film, etc.
What is the relationship between the coating rate and the unit price of coating square meters? Let's take rock slice paint as an example:
As shown in the figure, when the coating rate of lacquer in the rock slices increases to 0.
3, the cost change is significantly reduced, so it is the best cost to control the coating rate at about 0.
Cost analysis of construction methods
There are many ways to apply paint, such as rolling brush, smearing, spraying, scraping, etc.
The details can be seen in the following table:
Considering the cost, the texture coating and real stone paint adopt the process of wiping, and the cost is lower
Cost analysis of other factors
1 Whole body and non-whole body construction
From the cost point of view, the non-full body is 7-8 yuan/m2 higher than the full body, and it is recommended to use the full body construction first.
2 Overall construction and color splicing
Optimizing the splicing of patterns and reducing labor and auxiliary materials is one of the ways to control costs.
From a cost point of view, it is recommended to give priority to monochromatic overall construction in paint selection
3 Flatness of external walls
The simpler and flatter the exterior wall, the lower the amount of paint, the more conducive to cost control
Therefore, it is necessary to control the number of facade lines and improve the flatness of the facade insulation
As the complexity of the exterior wall lines increases, the cost will continue to increase
According to the cantilever type or depth type of the external wall balcony, it has an influence on the amount of external wall paint.
Controlling a reasonable balcony form is one of the methods to control the amount of paint.
The flatness control of the insulation surface directly affects the amount of putty at the base level and the overall effect
4 Process arrangement
Improve efficiency and control material loss through process arrangement; avoid repetitive and ineffective construction, and do a good job of flow-through construction process arrangement
Case analysis of exterior wall coating optimization
Optimization case 1: Optimal selection of elastic garland types
According to a project that the cost of large garland is slightly higher, but the visual effects of more than three layers are not much different from that of small flowers and medium flowers, the overall large garland is changed to the method of imperial color stone combined with small garland, which saves 41% in cost.
Wan, in terms of effect, it not only shows the texture advantage of imperial color stone at close range, but also effectively applies the feature that the long-distance difference of the garland effect is not obvious.
Optimization case 2: Optimum types of texture coatings
A flat exterior wall paint in a residential area was made of coarse sand, and then passed the actual sample effect test and changed to medium sand with a corresponding cost balance of 800,000
Optimization case 3: Line optimization
A project simplifies complex lines, reduces construction difficulty, speeds up the progress, reduces material consumption, and shrinks costs.
Assuming that each building optimizes the lines of two parts, the project has a total of 25 buildings, and the total optimization amount is about 1.
Optimization case 4: Optimization process
The initial positioning of a project did not refine the exterior wall coating method.
In the deepening design stage, through the joint negotiation of cost and research and development, the two-pass color surface layer method was changed to a whole body construction method combining middle paint, top paint and color materials.
, The exterior wall coating area of the project is 70,000 m2, saving about 560,000 in cost
Summary of knowledge points
Cost optimization control points for exterior wall coatings:
(1) Selection of ingredients: The middle paint of real stone paint is changed from silicon-acrylic to pure acrylic, and the cost is reduced by 13 yuan/m2;
(2) Optimization of the style: the cost of changing the large flower to the medium flower with elastic garland is reduced by 3 yuan/m2, and the cost of changing the texture of coarse sand to medium sand is reduced by 10 yuan/m2;
(3) Process optimization: the texture coating and real stone paint adopt the process of wiping, and the cost is lower;
(4) Process allocation: Reasonable process allocation, avoiding repeated and ineffective construction is an effective way to control costs;
(5) Full-body and non-full-body construction: Change the non-full-body construction to a full-body construction cost to reduce 7-8 yuan/m2;
(6) Overall construction and color splicing: the cost of color splicing will be reduced accordingly if the color splicing is changed to monochromatic;
(7) Outer eaves lines: the complexity of the lines affects the cost of coatings, the more simplified the lines, the lower the cost;
(8) Balcony type: the cantilevered balcony is changed to the deep type, the cost of coating is reduced, and the safety factor is increased;
(9) Basic level: The putty process can be canceled if the basic level is level and there is no back alkali and other factors, and the cost is reduced by about 4.
Cost control points for exterior wall coatings at various stages of development
Cost management runs through the project.
In summary of the cost control points of exterior wall coatings, effective application in the positioning, bidding, construction and other stages is the key to controlling the cost of exterior wall coatings.
Positioning stage: category selection (comparison of fine sand and coarse sand), category optimization (match of imperial color stone + small garland), as well as substitutes for high-priced materials in secondary parts, etc.
Bidding stage: Evaluation of the constituent elements of the quotation (the impact of the same type of paint on the cost due to the replacement of the emulsion and the adjustment of the coating rate), the technical solution, the evaluation of the basic treatment, the process arrangement and the selection of construction methods such as whole body and non-whole body Wait;
Construction stage: basic quality control and cheap and effective treatment methods (such as the flatness of external wall insulation board, the water-based or pickling of the alkali surface layer, etc.
), the optimization of the painting process, the prevention of cross-construction loss and the outer eaves lines, etc.