If you want to change your wall color, what is needed?

Hello community how are you today? hopefully, still healthy and free from COVID-19, today I will share with you how to calculate the needs of workers and what is needed to scrape wall paint.

Usually, the wall paint you use has a limited usage time, there is shelf life of up to 5 years, but there are also those that only last up to 2 years depending on the quality of wall paint you use, walls will be dull and opaque and a building will look no longer attractive.

If you just add (overpainting) an old paint with new paint, your old wall paint will be primed (base paint), but with suboptimal results, for example, the resulting color will be different from what you want or the paint that looks at certain areas will be thinner. and it could be because your old paint is used as a base, there is a chance that your new paint will peel off faster than the specified factory age.

So what should be?. I suggest you should first peel your dull paint, then you can start painting with a new color/original color. It will be a little longer because it takes time to peel your old wall paint and the additional costs. but don't you need a building that has a more beautiful appearance?

How do you calculate the worker's needs and what is needed to peel your old wall paint?
We will give an example of a field 4 meters long and 4 meters high.
The material you need for this job is Sodium Hydroxide (NaOH), NaOH will react to the old wall paint that you will peel because a handling time is faster than using manual scrap, so this material (NaOH) is also widely used in the construction field.

In accordance with the regulation of the Indonesia Minister of Public Works (Work Unit Price Analysis, Number 11 of 2013)

Is known :

Items	Information
Length	4.00 m
Height	4.00 m

Answer :

Items	Information
length x height	m2
4.00 x 4.00	16.00 m2
Total amount	16.00 m2

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CALCULATION OF LABOR AND MATERIAL REQUIREMENTS

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Analysis of division A.4.7.1, number A.4.7.1.1. about the need for 1 m2 Scraping the surface of old paint is.

Items	Information
Worker	0.1500 Person Per Day
Foreman	0.0030 Person Per Day
NaOH (Sodium hydroxide)	0.0500 Kg

^{Sodium hydroxid, Image Source wikipedia.com}

Then we will make the calculation according to the analysis mentioned above.

Items	Information	Amount
Worker	0.1500 Person Per Day x 16.00 m2	2.400 Person
Foreman	0.0030 Person Per Day x 16.00 m2	0.048 Person
NaOH (Sodium hydroxide)	0.0500 Kg x 16.00 m2	0.800 Kg

After you finished scraping your old wall paint, your next step is to clean it, because if a wall that has been peeled using NaOH is not cleaned, it is feared that it will affect the quality of your new wall paint. So the next material needed is soap, you can use any type of soap that is important that is cheap and easy to obtain.

The analysis that we use is Analysis of division A.4.7.1, number A.4.7.1.2. needs 1 m² Washing the surface area of the wall that has been painted.

Items	Information
Worker	0.1500 Person Per Day
Foreman	0.0030 Person Per Day
Soap/Suds	0.0500 Kg

Then the calculation.

Items	Information	Amount
Worker	0.1500 Person Per Day x 16.00 m2	2.400 Person
Foreman	0.0030 Person Per Day x 16.00 m2	0.048 Person
Soap/Suds	0.0500 Kg x 16.00 m2	0.800 Kg

^{The process of stripping, cleaning and repainting a building with new paint has been completed. Image Source @kharrazi}

Conclusion
Scrape the surface of the old wall paint is needed if you want to paint the walls with new paint, according to the example above then to complete the job is needed

Items	Information
Worker	4.800 Person Per Day
Foreman	0.096 Person Per Day
NaOH (Sodium hydroxide)	0.0500 Kg
Soap/Suds	0.0500 Kg

After the work of scraping the surface of the wall paint and cleaning is complete, then the next stage you can start painting your old wall with new paint.
You can also calculate the needs of workers and paint material in my previous post ( how much labor and material needs for painting work).

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<sup>Reference
1. AHSP ( Unit Price Analysis of Work ) Cipta Karya (PDF)
2. Wikipedia.com-Sodium hydroxide</sup>

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