We’ve revealed to you that the secret behind a good painting job is proper and adequate surface preparation.  But, we’ve barely scratched the surface with our article about the basics of surface preparation for new concrete.  There’s more to learn about preparing previously painted concrete surfaces.

Surface preparation for old painted walls is a little different from new concrete because previously painted concrete surfaces can have an existing problem that needs to be treated first.  As a general step, you must always observe the condition of the surface that needs repainting. From there, you can take a specific course of action or treatment. In this article, we break down for you several painted concrete wall issues and expert-approved tips on treating them.

How to Deal with Peeling Paint

How could you tell when your old painted concrete walls have peeling paint?  Simple, it’s when the paint film does not adhere to your concrete walls anymore.  When this happens, our paint expert recommends that you scrape off all the loose, scaling, peeling, or flaking paint. Then, clean the surface to fully remove dust, dirt, oil, grease, and other contaminants.

Common Painting Problems: What is Peeling?

You can read more about peeling paint here.

How to Prep Chalky Surfaces

When old paint on concrete walls are chalking, powder comes off and sticks to your hand once you touch it. Before applying anything, get a clean damp rag or brush to scrub the surface clean. Let the surface dry thoroughly before you start priming. Then, you can treat chalking by applying BOYSEN Chalk Blocker B-7304, using a brush or roller. The chalk blocker will also serve as your primer. This premium formula binds chalk residue to the substrate to help maintain its good condition even after months of application. After priming the concrete wall, wait two hours for it to dry before applying the topcoat.

Take note that if the chalking is severe, experts recommend that you fully scrape off the paint.

For a more in-depth discussion of chalking, follow this link.

How to Treat Mildew-Infested Walls

Common Painting Problems: What is Mildew?

Your interior walls can have mold or mildew or those dark unsightly patches. You will usually find mold and mildew on bathroom concrete walls, kitchen tiles, or wash areas because they feed on moisture to survive and thrive. If you notice mildew infestation, you can apply a bleach solution (one part laundry bleach to three parts water) to the surface using a clean rag or a brush. Let it stand for 24 hours before washing it off. Let it dry completely before repainting.

Learn more about mildew on surfaces here.

Once you’ve treated, cleaned, and dried off the surfaces, follow the recommended system of painting. Firstly, apply the primer on bare surfaces. Then, cover hairline cracks and minor surface imperfections with putty. Finally, apply the topcoat.

Watch Boysen Painting 101 if you want to know more about how to prepare other surfaces like metal or wood.

If you have technical questions or request for clarification about your painting projects, please call this number (02) 363-9738 local 417 to 418 during office hours and talk to our Technical Team. You can also write an email to ask@myboysen.com.

Yasmin Aguila

Yasmin is a copywriter who writes poems when she is in love. She is also a feminist and a film enthusiast.


  1. Avatar
    Jane consigo Reply

    Ask ko lng Po ano dapat gawin sa concrete na nalagyan na Ng waterproofing paint pero natagas pa Rin pag naulan …tnx Po

    • Annie H Adlawan

      Hi Jane, our Social Media team sent you a reply but I’m sending it here again to make sure you get your reply.


      Thank you for your comment and for following us at Let it B.

      Para sa iyong concrete surface, kung may concerns pa rin after gumamit ng conventional waterpoofing products, advisable na kumonsulta sa mga professionals tulad ng waterproofing experts o contractor para sigurado ang pag-aayos ng iyong problema.

      Kailangang ayusin muna ang cause ng pagtagas ng tubig (ex: mga cracks sa exterior walls, sirang linya ng tubo, mga butas, at/o iba pa) bago mag-painting o repainting. Magpapabalik-balik lang ang problema kung hindi muna ito magagawa.

      Thank you and have a great week ahead.

  2. Avatar
    Carl jeson p.opena Reply

    Gud am po bkit po ngkaron Ng lobo\bubbles Yung posted n pininturahan k eh 2weeks npo sya nkapahid tas 3days p nguulan eh tnatamaan psya Ng tubig nglobo po Anu po Kya Ang remedyo don eh smantalang elastomeric po gnamit ko sun and rain…Ptulong nmn po kng anu remedyo don…

      • Annie H Adlawan

        Hi Carl, Nag bounce back iyong email to you from our Technical Team. Eto iyong sagot:

        “Salamat sa iyong comment at sa pagtangkilik sa Let it B.

        Base sa iyong description, mukhang may water seepage ang iyong pader.
        Para masolusyunan ang pagkatas ng tubig, mainam na hanapin muna ang source ng tubig. Maaaring mga cracks sa exterior walls, sirang linya ng tubo, mga butas, at/o iba pa. Kailangang ayusin muna ito, bago mag-repainting. Magpapabalik-balik lang ang problema kung hindi muna ito magagawa.

        Advisable rin na kumonsulta sa mga professionals tulad ng waterproofing experts o contractor para sigurado ang pag-aayos ng iyong problema.”

        Pag meron ka pang tanong, please send an email to ask@myboysen.com o kaya tumawag sa (02) 363-9738 local 417 to 418 during office hours.

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