Collection: Planter Box Seal

Waterproof Your Planter Box

All Planter Boxes need a Seamless Waterproofing Membrane to contain all the ponding/continuous moisture, bugs, bacteria and fertilisers found in the soil.

Our RTT - Waterproof Sealant is a scientifically engineered hybrid liquid rubber that has a unique resistance to protect against the above and can extend the life of your planter box up to 10 years or more. 

Find all products needed to waterproof your Planter Box below ↓

RTT Planter Box Waterproof Products

For all your planter box needs , buy RTT waterproof sealant products.

  • Step 1:

    Make sure the surface is clean and dry. Use a pressure washer/water blaster to clean the surface.

    Allow the surface to dry before proceeding to the next step.

  • Step 2:

    Cover and Sandwich the RTT - GEO Textile with the ultimate waterproofing sealant over seams, screws, nails and outlets. Use RTT - Seam Tape to cover bigger holes or cracks.
    Allow curing for 24 hours.

  • Step 3:

    Apply up to 3 coats of our RTT– Waterproof Sealant over the planter box inside surface. (Up to 1mm thick each.) 
    Allow curing for 4-6h between each coat. 
    Use RTT - Quick Dry to spray on the wet Waterproof Sealant layer for a quicker curing time and to protect the Sealant from approching rain.

  • Step 4:

    Clean UP:
    Use our RTT Sealant Cleaner to remove any spillage, drips or splashes of the RTT - Waterproof Sealant.

  • Step 5:

    Allow 7 Days to cure before putting the soil into the Planter Box.

  • Step 6:

    Make sure there are no stones or sharp objects in the soil. The best practice is to put a corflute between the membrane and the soil to avoid the membrane being cut by a sharp stone in the soil.  

  • Trade Tipp:

    All planter boxes must have a drain system fitted to avoid the roots of the plants becoming waterlogged and dying.


How much Product do I need?

You will need a minimum of 2L/m2 of RTT - Waterproof Sealant for concrete surfaces.

You will need a minimum of minumum of 1.5L/m2 RTT - Waterproof Sealant for metal surfaces.

How long does it last?

We've been testing and improving our products since 2008. When properly applied the Waterproof Membrane will extend the life of your Planter Box by 10+ year.

Why do i need the GEO Textile?

The GEO Textile is sandwiched with the Waterproof Sealant over cracks, holes, seams, vents etc. It is used for reinforcement and stabilisation purposes.

What is the Seam Tape for?

The Seam Tape is used to cover bigger holes and cracks as it is firmer than the GEO Textile. Like the GEO Textile, it is used for reinforcement and stabilisation purposes.

Why do I need the Quick Dry Spray?

The Quick Dry Spray is optional. However, we recommend spraying it on top of a wet Waterproof Sealant layer for a quicker cure and to protect it from moisture.

DIY is not an option for you?

We work with accredited contractors and take on large commercial projects.

Contact us on or use the Contact form and let's discuss your project!