Should You Do a Flat Roof?

What’s Your Ideal House?

When people imagine a house, many picture a building with a pitched or A-shaped roof. However, this is far from the only option available for your home or business. One style to consider is a flat roof, which is a horizontal roof that is usually tilted at a very low angle.

Reasons to Choose a Flat Roof

People choose flat roofs for a variety of reasons. Some simply like the way they give a home a more modern look. Others appreciate advantages such as:

  • Low cost: Flat roofs are generally easier to design and construct than angled roofs. Depending on the materials you use, they can cost significantly less money to build.
  • Accessibility: It is much easier to access a flat roof for maintenance or repairs. Some people with flat roofs even use them for gardens or other projects.

However, it is important to note that there are also disadvantages to living in a building with a flat roof. For example, these roofs require careful maintenance, or they can be damaged by weather and gradual wear and tear. They can also be prone to water pooling and flooding.

Before choosing a roof design for your home, it is important to be fully informed about your options. Our roofing specialists can help you review your choices when designing a home or constructing a new roof.

Flat Roofing System Options

Foam Roofing

Foam roofing is the most energy-efficient roofing material available, over 500% more efficient than conventional roofs. It’s the first intelligent roofing technology for flat and low-sloped roofs, combining insulation and roofing into one material. That means no roofing seams or multiple layers – eliminating the expanding and contracting and separating that allows water and microbes to seep in and damage your roof.

Each Mikku and Sons foam roof is custom installed. The foam is sprayed on as a liquid mixture, and within a few seconds will expand to up to 30 times its original volume.  It will become a watertight, seamless solid that custom forms to the roofing substrate. Take a look at the advantages of a Mikku and Son’s foam roof:

  • Tough, seamless construction
  • Can be sprayed onto almost any surface including irregularly shaped roofs and uneven surfaces
  • Tenacious adhesion – demonstrated in the most recent Florida hurricanes
  • Moisture resistant – even when the membrane coating is damaged
  • Inch-per-inch, the highest energy efficient roofing material available
  • Extremely strong – yet ultra lightweight
  • Proven longevity classifies it as a sustainable low-slope roofing system
  • In most cases requires only periodic recoating for decades of service

Built-up Roof Membrane (BUR)

  • Assembled in place using multiple plies of asphalt- impregnated felt bedded in bitumen.
  • Asphalt or coal-tar is applied hot in order to merge with the saturant bitumens in the felt and form a single-piece membrane.
  • The felt is laminated in overlapping layers to form a membrane that is two to four plies thick.
  • The membrane is protected from sunlight and physical wear by applying a layer of aggregate (such as crushed stone or other mineral granules) embedded in the surface ply.

Elastomeric/Plastomeric Roof Membrane

  • Sheet materials applied to the roof in a single layer.
  • They require less on-site labor than built-up roofing and are usually more elastic and, therefore, less prone to cracking and tearing.
  • They may be affixed to the roof with adhesives, by the weight of a gravel ballast, by fasteners concealed in the seams between sheets, or with mechanical fasteners that do not penetrate the membrane.
  • Types of Elastomeric/Plastomeric Roof Membranes include the following:

Neoprene (Polychloroprene)

  • A high-performance synthetic rubber compound applied in sheets ranging from 0.030 to 0.120 inches thick and joined at the seams with an adhesive.
  • Vulnerable to attack by ultraviolet light; therefore, it is usually coated with a protective layer of chlorosulfonated polyethylene.
  • Vulnerable to aromatic solvents and strong oxidizing chemical.
  • It may be fully adhered to the roof deck or partially adhered, with aggregate ballast to prevent wind uplift.

EPDM (Ethylene Propylene Diene Monomer)

  • The most widely used material for single-ply roof membranes.
  • A synthetic rubber manufactured in sheets ranging from 0.030 to 0.060 inches thick and joined at the seams with an adhesive.
  • Vulnerable to petroleum products and plastic roofing cement.
  • It may be fully or partially adhered, or used in a protected membrane roof.

PVC (Polyvinyl Chloride)

  • A thermoplastic compound commonly known as vinyl.
  • Relatively inexpensive.
  • PVC sheets for roofing range from 0.032 to 0.060 inches thick, and are joined at the seams by solvent or hot air welding.
  • Vulnerable to ultraviolet radiation, petroleum products, and coal tar.
  • It may be fully or partially adhered, or used as a protected membrane.

Chlorinated Polyethylene and Chlorosulfonated Polyethylene Sheets

  • Vulnerable to petroleum products.
  • Not compatible with PVC.
  • Highly resistant to ultraviolet deterioration and can be manufactured in light, heat-reflective colors.
  • Used on roofs where aggregate ballasting is unacceptable for reasons of appearance or excessive slope.

Polymer-Modified Bitumens

  • Vulnerable to petroleum products, hydro-carbons, and some chemicals.
  • Formed into composite sheets with various other materials.
  • Some are intended to be laid loose, others to be adhered to the roof deck or insulation.

Fluid-Applied Roof Membrane

  • Used primarily for domes, vaults and other complex shapes that are difficult to roof by conventional means.
  • Applied usually in several coats using a roller or spray gun. When it cures, it forms a rubbery membrane.

Factors Contributing to Flat Roof Deterioration


  • Hot sunshine on a roof causes the volatile ingredients of tar or asphalt to evaporate.
  • The asphalt oxidizes and becomes brittle.
  • The roof mat eventually loses its elasticity, the surface coating becomes checked and flakes off, exposing the felt below.

Temperature Changes

  • Expansion and contraction place strains both on the roof structure (deck and walls) and strain the flashings. These strains can cause the roof mat to tear and mortar in coping joints to crack, providing sources for water entry.


  • A strong wind can drive rain into defective joints in the mat or parapet, can cause the roof to tear at loose seams and can cause the roof structure to sway.

Outside Interference

  • Roof mats are not designed for extra accessories such as signs and electric wires, nor are they intended for regular foot traffic. Anchorage planks pierce both the mat and the deck causing serious damage.
  • Pollutants, acids and saturated animal fats can potentially damage membrane roofing. Protection from these is provided through coatings and/or ballast covering.


  • Water can seep into a dry roof through cracks and cause a leak.
  • This moisture can turn to ice in freezing temperatures and can cause the roof to tear or heave.


  • As walls settle, extra strain may be exerted on flashings, or the roof may settle below the level of the drain pipe. This will either cause a backup of flood water, or a leak through the crack around the drain.

Emergency Roof Repair Contractors

Mikku and Sons Roofing has been helping residents throughout Phoenix since 2001. Our experienced and friendly crew members can inspect your roof and help you get it ready for the monsoon season to help you reduce the risk of damage. If your roof has damage from monsoon storms, we are ready to help you with quick and complete roof repair. We have experience in all types of commercial and residential roofs, including tile, shingle and flat roofs. We are fully licensed and insured and make it our mission to provide quality workmanships and exceptional service.

Call us today at (623) 465-1068 to find out how we can help you prepare your roof for the coming monsoon season or to repair it after a storm.

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