Throughout the year, our Technical Team and social media channels get a lot of questions about the Boysen Plexibond Cementitious Waterproofing System. By the way, hindi siya Flexibond, Plexibond siya, with a P as in Pinas. If you search for Plexibond in this Let it B blog, you will find seven posts about it. Here they are:

How to Use Boysen Plexibond – Waterproofing Your Roofs and Walls
Product Highlight: Boysen Plexibond
Boysen Plexibond Dos and Don’ts
Waterproof Your Home with Boysen Plexibond
No, You Can’t Use Boysen Plexibond on Its Own
Your Comprehensive Guide to Boysen Plexibond

If you’ve read all the six posts above, try this quiz to test your knowledge.

Frequently Asked Questions about Boysen Plexibond

Boysen Plexibond is a cementitious waterproofing system. It is a specially formulated, water-based acrylic polymer designed for mixing with Portland cement before application. Mix 6.5 to 7.5 kgs of cement to 4 liters of Plexibond. Do not add anything else to the mixture.

On which surface can I use Boysen Plexibond?

Plexibond can be used on a BARE concrete surface. In other words, the surface must have no paint and no tiles. The reason why Plexibond has to be applied on bare concrete is because the mixture of acrylic polymer and cement weighs heavier than a usual coating. Therefore, it needs a bare and sturdy surface to adhere to.

If the surface has been painted, scrape off the paint first, then prepare the surface properly before you apply Plexibond to ensure a leak-proof paint job. Read this post to know more about surface preparation for concrete walls that have been painted.

You cannot use Plexibond in submerged areas like pools, ponds, or cisterns. Plexibond can’t swim.

Where can I  use Boysen Plexibond?

Common applications are on:

  • firewall
  • ledge/canopy
  • concrete gutter
  • parapet wall

Pwede bang hindi haluan ng semento?
Pwede bang tile grout / tile adhesive / putty / skimcoat nalang ang ihalo?
Pwede bang pintura nalang ihalo (para may kulay na)?

Ang sagot ay NO, NO, and NO.

Plexibond is NOT a stand-alone product. It has to be mixed with Portland Cement, and ONLY Portland Cement. Again, the correct ratio is 6.5 to 7.5 kgs of Portland Cement to 4 Liters of Plexibond.

And to those who asked the third question, brownie points for trying to think of ways to cut the process. But if you do this, you will have to redo the whole process from beginning to end in the right way, so in the end it will take longer and it will be more expensive.

Watch this video tutorial to learn how to use Boysen Plexibond. For written instructions, visit the website.

Pwede bang pinturahan ang pader na may Boysen Plexibond?
Kailangan bang pinturahan ang pader kapag may Boysen Plexibond?

Yes, we highly recommend a paint system for maximum durability. Here are the Boysen products you can use:

Pwede bang ipahid sa loob ng bahay ang Boysen Plexibond?

Yes, you can use Plexibond as a waterproofing system for your bathroom, provided that there is no existing paint and that tiles will be installed after application.

On which side of the wall do I apply Boysen Plexibond?

Apply it on the positive side of the wall, meaning, that side where the water pressure comes from.

Can I use Boysen Plexibond to cover cracks?

Yes, you can use Plexibond, but only for hairline cracks. It will not bridge gaps and active structural cracks. In such cases, call a professional like a contractor or a structural engineer.

Pagkatapos kong mag Plexibond, pwede ko bang masilyahan ng Skimcoat para makinis?

No. Ang Konstrukt Permaplast K-201 High Performance Acrylic Skimcoat ay pinapahid as alternative plastering on bare concrete walls. Pinapahid ito bago maglagay ng Plexibond. So first Skimcoat and then Plexibond.

Call the Boysen Technical Team

The application of Boysen Plexibond is fairly complex, thus we do not recommend it for DIY projects. You need professional painters to do the job for you.

But even if you will not be applying Plexibond yourself, it always helps to have an understanding of the process. Our Technical Team is ready to answer any questions you may have about the product. Just call (02) 8363-9738 local 417 to 418 during office hours.


Annie is the Managing Editor of Let it B | MyBoysen Blog. An unrepentant workaholic, she runs this blog and her own company Talking Lions ( She thrives on collaborating with people who are good at what they do, and working together with them to create something special. Annie learned interior styling while managing her own wholesale business in the Netherlands, importing high-end, handmade home furnishings to stock four outlets and a showroom in the country.


  1. Good morning, my firewall was painted with flexibond last 3 years ago, could i repaint it again without scrapping the old flex?

    • An email was sent to you a while ago. We need the following info to help you better:

      Regarding your project, may we clarify:
      1. Did you apply paint on your firewall after putting on BOYSEN Plexibond Cementitious Waterproofing System?
      2. Have you experienced water seepage recently?

      Please reply directly to

  2. Hi, is it advisable to reapply skimcoat k201 or 202 to wall to render industrial finish with previously applied skimcoat201 & penetrating sealer.? Please advise po.

  3. Pwede po bang idirect ipahid ang flexibond sa wall na walang halong semento…

    • Para sa iyong tanong, hindi po pwedeng gamitin ang BOYSEN Plexibond ng walang hinahalong semento. Formulated na haluan ng 6.5 – 7.5 kg Portland Cement ang bawat 4 Liters ng BOYSEN Plexibond bago ipahid.

      Click here para sa product details at instructions ng BOYSEN Plexibond:

      • johner laguitan Reply

        pwede ba gamitin ang plexibond sa loob ng cistern tank

        • Para sa iyong project, hindi po pwede dito ang BOYSEN Plexibond. Hindi siya formulated for use sa submerged areas, tulad ng ponds, pools at sa loob ng tanks.

  4. Nagpahid kami ng plexibond sa rooftop. Tama naman mixture namin na 7 kgs cement sa 4 lys na plexibond. Noong matuyo ay nag crack yong flexibond. Nagtuklap din yong iba. Ano kaya ang sanhi nito?

  5. pwede ba sya sa flooring ng bathroom bago mag tiles?

    • An email was sent directly to you on February 24, as follows:

      Para sa iyong tanong, kung wala pang pintura o waterproofing system ang concrete flooring, pwede po kayong gumamit ng BOYSEN Plexibond.

      3 – 5 coats ang recommended ipahid dito. Patuyuin ito ng at least 1 day bago maglagay ng 1 coat bond coat (purong BOYSEN Plexibond). Habang tacky o sticky ito, maglagay ng concrete o mortar topping bago lagyan ng tiles.

      Click here para sa product details at instructions ng BOYSEN Plexibond:

    • Pwede po bang ipahid ang plexibond kapag may skim coat na ang pader?

      • Para sa iyong project, clarification lang:
        1. Nasa loob o labas ng bahay ang kongkretong pader?
        2. Anong skimcoat ang iyong ginamit?

          • Powdered skimcoat ang ginamit, tama po?
            Tapos CR po ba ang pagpapahiran ng BOYSEN Plexibond? Kung hindi, saan po manggagaling ang tubig? Sa labas ba (ex: tubig ulan)?

            That was sent to you via email. Please reply directly to the email.

  6. patrick vargas Reply

    Hi. I am currently working on a thesis about rice husk added to the concrete mix for hollow blocks making. I would like to know if the waterproofing power of BOYSEN plexibond would work if we add it in the mix. Thank you in advance.

    • We are sorry to inform you but BOYSEN Plexibond is not a food grade waterproofing system. Boysen does not have any food grade products.

  7. Sandy Beringuel Reply

    Hi Team,

    Good day.

    Tanong ko lang po kung pwede magkabit ng TILES sa WALL na may PLEXIBOND?

    Balak ko po kasi na lagyan muna ng PLEXIBOND ang WALL bago lagyan ng tiles.

    Hoping to hear from you soon.

    Thank you.


    • Para sa iyong tanong, pwede naman pong lagyan ng tiles ang pader na may BOYSEN Plexibond. Para sa kongkretong pader, 2 – 3 coats po ng BOYSEN Plexibond mixture ang recommended na gamitin. Patuyuin ito ng at least 1 day bago pahiran ng 1 layer bond coat (purong BOYSEN Plexibond). Kabitan ng tiles gamit ang tile adhesive.

    • Para sa iyong tanong, pwede naman pong lagyan ng tiles ang pader na may BOYSEN Plexibond. Para sa kongkretong pader, 2 – 3 coats po ng BOYSEN Plexibond mixture ang recommended na gamitin. Patuyuin ito ng at least 1 day bago pahiran ng 1 layer bond coat (purong BOYSEN Plexibond). Kabitan ng tiles gamit ang tile adhesive.

      For further questions, please email directly to

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