Test Plug

Wondercap's NEW Test Plugs are here to assist all trades and the DIY market for a convenient, budget-friendly method to maintain high standards for each project

Order your new test plugs today and never again stress about untested waterproofing. The waterproofing can make or break a project and fortunately it's often very simple to check that your waterproofing has been installed properly. With Wondercap's NEW Test Plugs you can test all jobs and allow the onsite manager to confirm for themselves.

NO more call backs, NO more second guessing, just pop it in, test it overnight and only get called if needing to touch up before any problems can occur!

Order your new test plugs today and never again stress about untested waterproofing. The waterproofing can make or break a project and fortunately it's often very simple to check that your waterproofing has been installed properly. With Wondercap's NEW Test Plugs you can test all jobs and allow the onsite manager to confirm for themselves.

NO more call backs, NO more second guessing, just pop it in, test it overnight and only get called if needing to touch up before any problems can occur!


Wondercap Test Plugs work with both acrylic and polyutherane waterproofing membranes.

How to order?

Wondercap would like to offer you a free trial run of our Wondercap Test Plugs. We have always endorsed 'better building practices', and a part of that is the testing of the waterproofing membrane and wet areas. It is with great pleasure that we offer you a FREE trial run our test plugs.

For the next 6 months, Wondercap will be including 4x test plugs per box to suit your purchased Wondercap kits.

Ends October 1st 2020

The Wondercap Test Plug fits tightly into the mouth of the installed Wondercap flange allowing the waterproofer, builder or plumber to accurately test that the wet areas are watertight.

The Wondercap Test Plug has been manufactured with a soft, flexible, lightweight plastic that will not damage the waterproofing membrane during testing or removal.

We are including Wondercap Test Plugs with every order of Wondercap Puddle Flange Kits for a trial period.

How to test your waterproofing using test plug?

  • Once the waterproofing has dried, insert the Wondercap Test Plug into the mouth of the installed Wondercap flange. The plug should fit tightly.
  • If the test plug does not seal tightly, clip the pull-tab and insert a second test plug into the existing one, increasing its girth.
  • Fill the wet/shower area with at least 30mm of water and mark the water height.
  • Leave to test overnight.
  • If the water level has reduced below the mark - look for leaks, then consult the waterproofer.
  • If the water level is unchanged, then you have successfully tested the waterproofing! Remove the test plug, drain the excess water and continue to bed and lay tiles.

How to order?

Wondercap would like to offer you a free trial run of our Wondercap Test Plugs. We have always endorsed 'better building practices', and a part of that is the testing of the waterproofing membrane and wet areas. It is with great pleasure that we offer you a FREE trial run our test plugs.

For the next 6 months, Wondercap will be including 4x test plugs per box to suit your purchased Wondercap kits.

Ends October 1st 2020

The Wondercap Test Plug fits tightly into the mouth of the installed Wondercap flange allowing the waterproofer, builder or plumber to accurately test that the wet areas are watertight.

The Wondercap Test Plug has been manufactured with a soft, flexible, lightweight plastic that will not damage the waterproofing membrane during testing or removal.

We are including Wondercap Test Plugs with every order of Wondercap Puddle Flange Kits for a trial period.

How to test your waterproofing using test plug?

  • Once the waterproofing has dried, insert the Wondercap Test Plug into the mouth of the installed Wondercap flange. The plug should fit tightly.
  • If the test plug does not seal tightly, clip the pull-tab and insert a second test plug into the existing one, increasing its girth.
  • Fill the wet/shower area with at least 30mm of water and mark the water height.
  • Leave to test overnight.
  • If the water level has reduced below the mark - look for leaks, then consult the waterproofer.
  • If the water level is unchanged, then you have successfully tested the waterproofing! Remove the test plug, drain the excess water and continue to bed and lay tiles.