Roof Waterproofing Costs & Repairs – FAQs

Roof Waterproofing Costs & Repairs – FAQs

How Much Does It Cost To Waterproof a Roof ?

Obviously there are various contributing factors affecting the cost of a roof waterproofing project  - especially if construction repairs & restoration are also involved.

  • Using Liquid Applied Membranes the spray application stage of a roof project can be determined with respect to time (weather permitting).
    Find out about Liquid Applied Membranes HERE
  • However a major cost is the time required to prepare a roof surface prior to waterproof membrane application.
  • The Team at Findlay-Evans pride themselves on painstaking and often hand detailing a roof site.
  • Great - not just good- preparation can mean the difference between waterproofing success or failure.

Meticulous waterproofing preparation means Findlay-Evans have confidence in our work, stand by our guarantees with excellent customer satisfaction.
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Roof Waterproofing Method - Preparation

  • Old roofs over the years accumulate layers of pollution, chemicals & materials.
  • These areas need to be thoroughly cleaned prior to waterproofing.

Case Study Video Below

Failed membrane due to bad preparation.

Failure to implement meticulous & rigorous preparation may mean the membrane, whatever method used, will not adhere to the substrate.

  • Waterproofing preparation is especially important for roof surfaces that we call "busy" i.e multitude of rooftop services & plant decks.
  • These areas need to be detailed and made water tight around, under and over all upstands, penetrations etc.
  • Time & method taken can be significant - hence preparation costs can add up.

Video Roof Case Study

Melb CBD Power Station requiring extensive preparation work prior to waterproofing.

  • Many leaking roofs have not been regularly maintained, and often have been subject to routine patch repairs .
  • Over the years we have seen it all.
  • The multiple attempts to stop roof leaks by contractors and maintenance crews using everything from caulking to TPO patches, even peel and stick roofing patches.
  • Often times patches do not adhere and only managed to hide evidence of membrane damage caused by saturation.
  • Previous repairs have to be eliminated or managed prior to installation of  a new membrane.

Case Study: Severe cracks on existing roof membrane

Cracks & voids covered - ready for spray application of Liquid Rubber

At some stage it becomes unmanageable to keep spending the maintenance dollar on short term roof repairs.

  • Many roof surfaces are well & truly at the end of their life cycle and in dreadful condition. In these cases roof surface cleaning, prepping  & detailing is time consuming.
  • Flat roofs, concrete & metal, have seams, flashings, vents, fastener holes, upstands for roof services, old layers of bitumen.............. the list goes on.
  • Existing roof penetrations may be historically sealed with only a bead of caulking.
  • Sheet membranes may have heat-welded seam failures that need detailing & preparation.

Roof preparation - ballast

Preparation of all seams & joins to waterproofing

  • Puncture holes can be prolific, from years of foot traffic servicing HVAC units, vibrational movement of the roof-mount equipment and thermal cycling.

Prepping & detailing makes a roof surface suitable for membrane installation.

Guarantees a robust, long life & strongly adhered waterproof membrane to the substrate.

Sheet membrane prepped & detailed along failed seam joins.

Sheet membrane deteriorated due to "ponding" water.


However the consequences of not doing this correctly is even more costly & time consuming. 

Solvent-free, water-based building products offer immediate solutions to both safer worksites plus quality, high performance adhesives and protection.

Read more. Findlay-Evans Recent Projects