Application Guide

Impermax QC liquid applied pond lining application guide

Surface Preparation

After you have dug out your pond you applied the concrete or brick surface you have to screed the pond to provide a smooth even surface and let the screed dry for about 20 days to be fully cured and for any shrinkage cracks to appear.

Clean the screed surface and remove any traces of dust, micro-organisms or materials which may interfere with the system adhesion.

Fill in any cracks/ fissures with an exterior Polyurethane Mastic -like Rayston Flex 3040 and then tape all cracks -ready for the application of the correct Primer


You have a choice of Primers depending upon what type of surface you have on your pond- and they are applied by roller or brush.

For Dry Concrete -the Primer is Porosity Sealer-which comes in drum sizes of 4kg and 20 kg. This is a clear 1 x component primer ( 1 x drum -so nothing to mix ) which dries quite quickly when the temperature is about 15 degrees. The Cover rate is between 100-300 gms per sq m so if you assume 200gms per sq. m.--then

4kg drum of Porosity Sealer will cover 20 sq.m. and 20 kg drum of Porosity Sealer will cover 100 sq.m.

For Damp Concrete- ( less than 12 % moisture )-the Primer is Humidity Primer which comes in drum sizes of 5kg and 18kg. This is a two part( 2x drums ) water based epoxy primer and after opening the drums you simply pour the small drum into the large drum and mix thoroughly with a slow speed stirrer. After application onto the screed the milky coloured primer should turn into a colourless film in 1-4 hours depending upon the temperature humidity and thickness.

The cover rate is between 200-400gms per sq.m. so assuming a cover rate of 300gms per sq.m.-then

5kg Humidity Primer will cover 16 sq.m and 18 kg Humidity Primer will cover 60 sq.m.


Application of Impermax QC- which comes in 3 x drum sizes with an application rate of 2kg per sq m applied in two layers of 1kg per sq m each.

Best to start with the walls of the pond, so that you can move around the pond without problems, and apply enough layers of Impermax QC until you reach the correct thickness. For vertical walls it will probably take 3 x layers of Impermax ( each 0.75 kg per sq metre ) to achieve the correct thickness of 2kg per sq m ( 1.8-2mm thickness )

For the Floor of the pond you will be able to apply the full thickness of impermax QC in two thick layers of each 1kg per square metre.

The Impermax Liquid Pond Liner and all Primers are applied by a roller or brush. The drying time for each layer of Impermax QC is approximately 4 hours ( depends on temperature )


In any waterproofing system you have to reinforce critical areas like upstands and where the floor of the pond meets to vertical walls and any changes of direction in the construction. At these critical areas we have to lay into the first wet layer of Impermax a simple Polyester reinforcement and saturate this polyester so that the white colour of the Polyester reinforcement does not show. When this first layer has dried we apply a second layer of Impermax to give the required thickness of 2kg per square metre ( 1.8 mm thick ).

This Polyester reinforcement is called Geo Max 80 and is available in 2 x roll sizes -100m x 0.3m wide and 100m x 1.0 m wide.

For Upstands and the area where the Base/ floor meets the vertical walls-- you should lay a 30cm x 1 m strip of Reinforcement into the first wet layer of Impermax. Half the 30cm strip of Geo max Polyester ( 15cm ) is laid up the vertical wall and the other 15cm is laid into the horizontal base of the pond, and is saturated with Impermax.

Curing Time

Allow a full 7 days to fully cure and then rinse the Impermax Surface with water and detergent -before filling your Pond with clean water.