FLAT ROOFS

A long term solution for ponding water

Flat roofs are a popular roof option in Hawaii since they are easy to construct and allow for design flexibility.  Unfortunately, their flat nature is their downfall.  Flat roofs tend to collect debris and pond water which will eventually cause leaks.  Luckily, coatings are a simple and great solution.

Flat roofs benefit most from a 100% waterproofing silicone coating such as our store brand CRS Silicone, CRS HD-50 Silicone, or GacoRoof Silicone.

Overview

In the beginning, all the roofs we did were hot asphalt. They were smelly and very unpleasant to install. Worst of all they cracked after about 10 years and you needed to haul them down to the dump. No matter what kind of flat roof you have — Brai, Capsheet or Pitch & Gravel — we firmly believe your best choice is to coat it with a 96% silicone coating.

Warranty

LeakMaster Roofing Labor Warranty

up to 7 years max per Hawaii State Law

Material Warranty

For Capsheet/Brai: up to 12 years
For Roof Coatings: up to 50 years

Manufacturer’s Labor Warranty

For Capsheet/Brai, IB, Duro-Last, Mulehide: up to 20 years

LeakMaster's Opinion

For decades roofers in Hawaii have tried to find a long term solution to ponding water on flat roofs.  Standing water, which creates mold and fungus growth, will break down the best of the traditional systems and force you reroof after 10 years or so.  

For commercial roofs we are long time applicators of Duro-Last Single Ply roofing.  It’s track record in Hawaii, when Leakmaster installs it, is 100% effective.

For homeowners a 96% solid Silicone roofs is just as good when applied correctly.

No matter what system you choose for your flat roof, we would avoid any asphalt system as they don’t last in our hot Hawaiian sun

Pros & Cons

Pros

  • 96% Silicones are cool, clean and long lasting with material warranties up to 50 years.

  • Duro-Last Single ply is custom cut to your commercial roof, like a tailored suit, and is billed as “The Worlds Best Roof.”  We have never had a major problem with any that we have put down in the last 10 years plus.

  • Silicone manufacturer’s have warranties that range from 20 to 50 years. So far all the 96% solid Silicones we have tested all appear to be very good–and very similar to each other.

Cons

  • Asphalt roofs, like Brai cap sheet, Alumination, pitch and gravel, etc are all dinosaurs.  They do, however, serve as a great base for applying silicones over.

  • Solvent based Silicones, such as GacoRoof, are long lasting but will not clean off easily

 
 
 
 
 
 
 

 

Frequently Asked Flat Roof Questions

Q: What should I know about my Flat Roof?

A:

Q: Which is best for my roof, Silicone or Acrylic Roof Coatings?

A:

Q: Should I do my roof before installing Solar PV?

A:

Q: Can I coat a flat roof?

A:

DO IT YOURSELF

Project Calculator


Calculations are estimates only. Additional materials may be required dependent on roof condition and other factors.

Step 1

Clean and let your roof dry completely! We suggest using a mild organic cleaner and a pressure washer if available, if not a hose and hard bristled brush should get the job done.

Step 2

Reinforce and seal any weak areas or cracks in the roof, these include roof seams, drip edges, pipes and any other penetrations such as solar. We recommend using a roof tape or fabric with a high grade roof repair sealant, such as CRS Mastic.

Step 3

Most top coats can go right over a clean, prepped, and dry roof.  Simply apply the desired top coat according to product instructions.  Caution: do not apply coatings if it is expected to rain within 1-2 hours.

POPULAR FLAT ROOF COATINGS

CRS Waterproofing Primer

  • Block Asphalt Bleed through.
  • Seal up bare wood.
  • Stop your roof leaks — 100% Waterproof
  • Thick, flexible base coat for silicones
  • Stretches 300%
  • Can be left exposed for 7 years without re-coating.

CRS SILICONE

  • 20 Yr. Material Warranty
  • 96% Solids
  • Non-Leveling formula for roof slopes up to 4/12 pitch (18 degrees)

CRS SILICONE HD-50

  • 50 Yr. Material Warranty
  • 98% solids means a thicker roof coating
  • Self Leveling Formula for flat roofs up to a 2/12 pitch (9 degrees)