Posts Tagged ‘flat roof systems’

Maintaining A Flat Roof

December 30, 2010

Flat Roof Maintenance

There is no perfect roof, but for some reason flat roofs never seem to get any respect!  The sloped roof is far and away the choice for residential construction, and more and more builders are putting them on commercial and industrial buildings as well.

Advantages Of A Flat Roof

The flat roof has many advantages and offers unique options that are too often overlooked and underrated.  For instance:

  • A flat roof is considerably cheaper to build than a sloped roof.  They can be built quicker saving money on labor, and they have less surface area requiring less expense for materials.
  • They are more easily accessible and far less dangerous than sloped roofs.
  • They offer more uses than just keeping the elements out (i.e. a flat roof can be used for storage or as a roof top garden and terrace.
  • Compared to a sloped roof, a flat roof provides you maximum functional cubic volume for your construction dollar.

Care & Maintenance Of A Flat Roof

Assuming a flat roof is constructed of high quality materials and skillfully installed (especially at the edges), the key to avoiding problems is regular inspection and maintenance.

  • Inspect your flat roof seasonally and even more often if you have trees nearby that can drop leaves and debris which clog drains and create water puddles.
  • Drainage is vital!  Always make certain drains are clear.
  • After heavy snow or a freeze-thaw cycle look for, and break up, ice dams which cause water build up.
  • Look for signs of “ponding” after rain.  “Ponding” means a low area must be built up with rigid insultation and resurface to ensure proper water flow.
  • Blistering or mushy areas mean that water has gotten between roofing layers.  These areas need to be cut out and replaced.
  • When the surface looks cracked or “alligatored” consider a new fresh application of roofing tar.
  • To extend the life of a flat roof consider applying reflective aluminum paint.  It will prevent ultraviolet light from breaking down the roofing material and keep the building cooler.
  • Make certain edges are sealed and all flashing is in good repair.

Flat roofs have many advantages and offer unique architectural and living options.  They can serve you faithfully for many years, but the key is regular inspection and simple maintenance when required.

Most important of all is that a flat roof must be designed and installed by a professional roofing company with the expertise, skill, equipment and materials to do it right.


Flat Roof Systems

October 12, 2010

Types Of Flat Roof Systems

Flat roof systems are roofs that are built so that they are nearly flat.  They are not completely flat; otherwise water would build up on the roof (called ponding) and would eventually start to get inside the building.  Flat roofs are built with a slight incline.  They are required to have at least a one-eighth-inch difference in height over each foot of the roof.   There are five main types of flat roof systems.

Roll Asphalt
A roll asphalt roof is made of material that is rolled onto the roof over roof felt and nailed down or applied with cold asphalt cement.  It is usually covered with a granular mineral surface, which looks like gravel.  The base material can be organic felt or fiberglass felt that is saturated in asphalt.  This is the cheapest building material, but it usually doesn’t last much beyond 10 years.

Single-ply flat roofs are composed of a single layer of a plastic or rubber-like compound.  Some of the more popular materials used today are thermoplastic polyolefin (TPO) and polyvinyl chloride (PVC), which are both very good at reflecting heat, which saves on cooling costs in the building.  Ethylene propylene diene monomer (EPDM) is also popular because it also cools well when white EPDM is used, and it is easy to install.  Rubberized asphalt is also used.  Single-ply roof systems, depending on the materials, can be self-adhered, applied with hot asphalt or installed by heating the back of the material with a torch.  Warranties for single-ply roofs usually are for 10 to 12 years.

Multiple-ply roof systems are also known as built-up roofs (BUR). These are made by overlapping rolls of felt or mats that are alternated with layers of asphalt.  This is covered by a granular mineral surface, ballast or tile to protect the layers.  These roofs can last 10 to 30 years.

Modified Bitumen
A modified bitumen roof is a multiple-ply roof that is made with modified bituminous membranes, which are made out of a blend of asphalt and a polymer.  This allows the asphalt to take on characteristics of the polymer, which is similar to materials used in single-ply roofs.  The modified bitumen roof is covered in a mineral or gravel surface, or a liquid coating that provides reflectivity.

Flat-seamed Metal
Flat-seamed metal roofs are made out of small sheets of metal that are soldered together.  The sheets are usually designed to look like tile or shingles.  The most common metals used for roofs today are copper, lead-coated copper or stainless steel. Metal roofs are light and reflect heat well, but are more expensive.

Types Of Flat Roof Systems

July 27, 2010

Flat Roofing

Although they are not as alluring as slate, tile or wood roofing, a flat roof is still extremely significant and may even require more attention.  Flat roof systems work by providing a waterproof covering over a building.  Water is then directed to drains, downspouts, and gutters by the slight pitch of the roof.

The Four Different Types of Flat Roofs

There are four main different types of flat roofing. They are:

  • Built-Up Roofing (BUR)
  • Single Ply Membrane
  • Sprayed Polyurethane Foam (SPF)
  • Roll Asphalt

Built-Up roofing (BUR) is composed of overlapping rolls of saturated or coated felts, literally built up to form layers. These roofs are designed to last 10 to 30 years, depending on the materials used.

Single Ply Membrane roofs come in two main types, thermoset membranes and thermoplastic membranes. Warranties of 10 to 12 years are typical, but as with any roofing system, proper installation is crucial and maintenance by the owner is still required.

Sprayed Polyurethane Foam (SPF) is a seamless roof system consisting of a layer of foam, sealed and protected by a resilient coating. It has been used successfully as a roofing and insulation material for over 30 years.

Roll Asphalt roofing has been used for the longest. This type of roofing typically consist of one layer of asphalt-saturated organic or fiberglass felt, applied with nails and cement, and then covered with a mineral surface. Generally, roll asphalt will last about 10 years.

Looking For More Information About Flat Roofing?

Roofing or re-roofing your home is a great investment. You’ll want to make sure you get a quote from a reliable roofing contractor.

EPDM Single – Ply Roofing Systems Part 2

July 13, 2010

How Long Do They Last?
As with most roofs, EPDM rubber roofs have varying lifespans that depend on numerous criteria.  These include environmental conditions such as what type of building (factory or church), how much foot traffic the roof gets, how much water remains on the roof after a rain, and how long it take that water to evaporate.  Not to mention geographical location.  Roofs in mild climates will outlast roofs in harsher climates.  Of course, one of the most important factors in a roof’s life expectancy is quality of workmanship.  If the roof is not properly installed, then its lifespan will be shortened.

Properly installed EPDM rubber roofs should last between 12 and 25 years.  Here’s a brief breakdown base on observations over the past 15 years::

  • 45 Mil Ballasted EPDM Rubber properly installed that drains well – 12 years
  • 45 Mil Mechanically Attached roof properly installed that drains well – 12 years
  • 45 Mil Adhered roof properly installed that drains well – 12+ years
  • 60 Mil Ballasted EPDM Rubber properly installed that drains well – 12+ years
  • 60 Mil Mechanically Attached roof properly installed that drains well – 15 years
  • 60 Mil Adhered roof properly installed that drains well – 15+ years
  • 80+ Mil Mechanically Attached roof properly installed that drains well – 20+ years
  • 80+ Mil Adhered roof properly installed that drains well – 20+ years
  • 80+ Mil Fleeceback Adhered roof properly installed that drains well – 25+ years

Available in a Variety of Membrane Thicknesses and Roll Sizes

Single Ply Roofing Systems

JM EPDM Roofing Membranes

Standard Roll Sizes (* Full-width, no-fold membrane)

Product Widths Lengths
45 FR 10′ (3.05 m) 50′, 100′ (15.24 m, 30.48 m)
20′ (6.1 m) 50′, 100′ (15.24 m, 30.48 m)
30′ (9.14 m) 100′ (30.48 m)
40′ (12.19 m) 100′ (30.48 m)
60 FR 10′ (3.05 m) 50′, 100′ (15.24 m, 30.48 m)
15′ (4.57 m)* 100′ (30.48 m)*
20′ (6.1 m) 50′, 100′ (15.24 m, 30.48 m)
30′ (9.14 m) 100′ (30.48 m)
90FR 10′ (3.05 m) 100′ (30.48 m)
45 R 10′ (3.05 m)
60 R 10′ (3.05 m) 100′ (30.48

Benefits Of TPO Single – Ply Roof Systems

June 3, 2010

Thermoplastic Polyolefin Roofing Membranes (TPO)

A typical low-slope roofing system consists of three components: a structural deck, a thermal insulation barrier and a waterproofing membrane, which consists of reinforcing fibers or fabric sandwiched between two sheets of flexible matrix.  The matrix material is either asphalt- or polymer-based.  In “single-ply” membranes, the matrix is made of flexible polymer.  The reinforcement provides dimensional stability for the membrane as well as strength to resist stresses in service.  It is generally made of chopped short glass fiber strands packed in a mat, or continuous polyester fiber arranged in a grid or in a non-woven mat.

Benefits of TPOs
The following benefits and characteristics of TPO are:

  • environmentally friendly and recyclable
  • seams can be heat welded
  • available in many colors
  • resistant to heat and UV degradation
  • resistant to may chemicals
  • good cold-temperature flexibility
  • no external plasticizers added

The result is an ideal commercial roofing system that is reliable and cost effective.  The TPO system is one of the latest single-ply, flat roofing technologies on the market today.  The TPO systems can be installed fully adhered or mechanically fastened.