We specialize in a variety of manufactures modified bitumen systems. We agree that the modified system is one of the more durable flat roof systems that stand to a test of time as well as excess wear and tear and normal elements caused by nature.

If your modified system is installed correctly, you should have years of protection with of course proper coatings and maintenance. We provide a commercial maintenance program to help insure each flat roof system last beyond its life cycle costs. Modified Bitumen systems come in a variety of colors in some locations of the USA. Most common color of Modified bitumen in the APP 180 White Granular, thus adding a solar reflective rating.

Some modified systems are installed over a tapered insulation, standard insulation slopes are 1/4 or 1/8 pending on the structural needs for draining. In Dallas, we are seeing a lot of slope roof structured with 1/2 plywood vs insulation which does not give you an r-rating. To us this is not correct installations but seems to be a sub-standard in the Dallas Metroplex

Modified systems are either heat applied, hot mopped applied or even cold process

The most commonly used process for adhering a modified system is heat applied.

Insure all flashings are primed prior to your modified bitumen roof system installation

We are strong supporters of Firestones APP 180 White Granular Modified Bitumen and APP 180 Smooth Modified Bitumen

Check Firestones Technical information here:::

Firestone APP Modified Bitumen Roofing Systems are available in a variety of thickness in smooth and granule surfaces. All Firestone APP membranes are reinforced with a tough, non-woven polyester mat. For new or re-roof applications, Firestone APP offers superior membrane performance and may be installed by heat welding or with cold-applied adhesives.

See the links below to access in-depth technical APP product information.

Technical Information Sheets

Material Safety Data Sheets

Product Lists

Application Guides

Code Approval Guide

Design Guide

Detail Drawings

Quick Specs

Modified systems are used to add a second layer over existing slag roofs. If the substrate decking is not saturated due to roof leaks and or prolong delays in roof maintenance.  You can add a recovery system to an existing roof using the APP 180 as a white cap and single ply - torch applied roof system. This system is installed properly should last 10-15 years in this Dallas heat

The next step would be to use coatings. The APP base will now allow for cost effective coatings versus replacement. Coatings are maintenance friendly versus gravel roof systems that are now considered out-dated

What is Modified Bitumen?

Polymer-modified roof membranes are composed of reinforcing fabrics that serve as carriers for the hot polymer-modified bitumen as it is manufactured into a roll material. MB roof system membranes are composed of multiple layers, much like BUR membranes. MB roof systems typically are installed as a two-ply system and almost always are fully adhered.

There are two types of MB roofing membranes:

• SBS polymer-modified bitumen membranes commonly are installed in hot moppings of asphalt (similar to BUR systems) or cold adhesive. Some SBS modified membranes are self adhering; that is, they contain an adhesive backing.
• APP polymer-modified bitumen membranes typically are heat-welded or torch-applied. Consumers should be cautioned that NRCA does not recommend torch-applying a modified bitumen membrane sheet directly to a wood deck.

A modified bitumen roof system is a hybrid built-up roof. It has the benefits of the built in redundancy of the BUR, along with the added strength, flexibility and UV resistance of a modified membrane.

Modified Bitumen or “modbit” membranes consist of an asphalt and polymer blend which allow the asphalt to take on characteristics of the polymer. There are several surfacing option for this system which include a factory applied mineral surface, a gravel surface laid in bitumen or a liquid applied coating that is typically reflective in nature. Typical lifespan of a modified bitumen roof is 10 to 20 years depending on weather conditions.

Types of Modified Bitumen Roof

APP Modified Bitumen, SBS Modified Bitumen (Smooth or Granulated)

Reflectivity of Modified Bitumen

The solar reflectivity of Modified Bitumen Roofs depend on the color of the surface layer.

Dark modified bitumen roofs can reach 150°F or more in the summer. The heat load of a dark roof can severely degrade the performance of air conditioning equipment.

Elastomeric coatings provide the highest reflectivity and is a very popular option for building owners. White roof coatings can reflect up to 90% of the heat from the sun.