Clear Coat Polyurethane Balcony Waterproofing

For years waterproofing a leaking balcony has consisted of the following process:

• • Stripping up the tiles
  • Ripping up the screed (under the tiles)
  • Taking the existing torch-on waterproofing off the slab
  • Then starting the same process all over again

• • • Re-waterproofing with torch-on
    • Re-screeding
    • Applying tile glue
    • Re-laying the tiles

Along with the above process comes the following:

• • Hammering noise (either by breakers or chisels). The hammering could produce plaster cracks on the surrounding walls from the vibrations.
  • Dust from the breaking up of the tiles & screed
  • Rubble and the carting away thereof. This could be a difficult situation if the balcony is on the 6th floor of an apartment block.

This method of waterproofing a leaking balcony can take up to 2 weeks, depending on size, to complete.. 

Some problem areas with waterproofing a balcony is the effective waterproofing of the water outlets on the balcony:

• • For some reason, construction of the balcony has the tiles and the screed riding halfway up the water outlet. It was explained to me by a builder that this is so the screed also has a chance to allow water ingress to pour out if water has gone into the screed. This is counter intuitive as the screed acts like tissue paper in a glass of water. Screed is very absorbent, so as the water runs over the tile into the outlet, it is absorbed into the screed.
  • Some outlets that I’ve seen, have cement at the join of the PVC pipe and the balcony. This cement also acts like tissue paper and absorbs water into the plaster surrounding the pipe.
  • When torch-on is applied to the rim of a full-bore outlet, it is cut to form in order to get into the outlet. I’ve seen poor application of the torch-on as it is very difficult to burn the torch-on into place in an outlet. This normally results in water being absorbed into the crack around the rim of the outlet, thereby resulting in water ingress into the screed or plaster.
  • Guarantees can range from 1 year to 5 years, then you have to start again should the balcony leak!

Any water that goes below the tiles causes a number of problems due to the fact that water expands and contracts at different rates to the screed and tiles. This often results in cracks appearing in the surrounding plaster. 

The ideal remedy is to stop any water ingress below the tiles. In order to achieve this, the balcony has to be “tanked” i.e., like putting a basin over the top of the tiles. This is where clear coat polyurethane comes into play.

Waterproof Doctor specializes in a clear coat polyurethane application that is applied on top of the tiles and into the water outlets. This application effectively creates a basin over the top of the tiles and does not allow any water ingress below the tiles. 

It normally takes 2 days to complete an average size balcony.

Points to ponder:

• • No breaking up of tiles, screed and waterproofing
  • No hammering, no noise, no dust and certainly no rubble to cart away
  • The polyurethane seals into water outlets effortlessly, creating a 100% seal
  • The polyurethane has a certified 25 year working life
  • The polyurethane has a manufacturers guarantee of 10 years
  • Waterproof Doctor will guarantee the workmanship for 10 years

In my opinion, there is no race when it comes to the common way of solving a balcony leak and applying a polyurethane solution.