Waterproofing & Common Problems

The following Waterproofing DIY Guide offers step-by-step instructions for waterproofing external plastered surfaces, exterior walls and face brick walls.

Waterproofing External Plastered Surfaces

Problem: Water-affected external plastered surfaces such as parapets, walls, pillars etc.

Waterproofing DIY Guide - Plascon MultisealSolution:

  • Ensure that all surfaces are clean, firm and thoroughly dry before painting
  • Repair and fill any cracks (see Common Problems)
  • Prime with Plascon Plaster Primer
  • Apply Plascon Multiseal by brush or roller and build up to a thickness of 1mm in 3 coats, allowing 4 hours drying time between coats
  • Finish with top coat of your choice

Waterproofing Exterior Walls

Problem: Rising and penetrating damp (occurs to 1.1m above ground level)

Waterproofing DIY Guide - Plascon DampsealSolution:

  • Remove any paint completely until you are back to a cement / plastered surface
  • Wash with Polycell Sugar Soap, rinse and allow to dry
  • Remove and repair poor plaster with Polyfilla Masonry Patching Plaster
  • Apply 3 coats of Plascon Dampseal, allowing 24 hours drying time between coats
  • Thin the first coat 30% with mineral turpentine
  • Finish with top coat of your choice

Waterproofing Face Bricks

Plascon BricksealProblem: Moisture ingressed through face bricks



IMPORTANT NOTICE: More detailed information as well as the full data sheets for each of the Plascon products mentioned and linked to above are available for free download from the Plascon website. Simply follow the link(s) and click on “Download Data Sheet” in order to access these.

Related Plascon DIY Articles:

2 thoughts on “Waterproofing & Common Problems

  1. Hi, I built a fishpond on the ground for the fishes. The problem that I have is I’ve tried lots of seal but it still leaks. Can you give me advice or can I use the one that they seal the swimming pools? It is a 1 x 1 meter fishpond.

    • Hi Mark, have you already tried using concrete to prevent your new fishpond from leaking? Please could you also clarify which swimming pool sealant you are referring to?

Leave a Reply

Your email address will not be published. Required fields are marked *