Commercial Built Up Roofs consist of multiple piles of roof felts laminated together with bitumen. Built-up roof material can consist of bitumen-saturated felt, coated felt, polyester felt or other fabrics. A surfacing is generally applied and can be asphalt, aggregate (gravel or slag), emulsion or a granule-surfaced cap sheet.
Built-Up Roofing is one of the most reliable ways of installing a new roof. It was first known as composition roofing and started in the 1840’s. Commercial Built Up Roof come in two basic types, asphalt and coal tar, and three basic components:
- the waterproofing component
- the reinforcing component
- the surfacing component which is used to protect the other components from the elements
The roofing membrane is protected from the elements by a surfacing layer, either a cap sheet or gravel embedded in bitumen or a coating material. The most common surface for a built up roof system, is a fiberglass mineral surfaced cap sheet. It offers a number of advantages. It has a white granular look, it is cost effective, and is relatively maintenance free.
Why is a multi-ply better than a single ply on a built up roof system?
The multiple layers of bitumen and bitumen-saturated “felts” make a watertight barrier capable of providing many years of reliable protection from the elements
- If the top layer is damaged, the subsequent layers underneath provide a back-up layer to stop water and the elements from entering the building.
- The create a more rigid and stable surface that make the roofing system more applicable to being a platform for your mechanical systems, solar energy systems, vegetative (roof gardens) or creating usable outdoor space by installing a roof deck over top of it.
- Many single-ply roofs these days are installing “sacrificial layers” underneath solar arrays; mechanical areas; and in high traffic areas to protect the primary membrane from damage.
Are Built Up Multi-ply Roofs energy-efficient?
Built-up roofing systems exhibit exceptional resistance to the conduction of heat between the exterior and interior of a building, resulting in noticeable reductions in heating and cooling costs.
- Built up roof systems incorporates the roofing insulation into the monolithic roofing membrane and results in better insulation or a higher R value for better thermal performance your roofing system can achieve.
- built up roof systems may have a ballast layer added to them (local building code permitting) which can increase the thermal performance. (Need Better Language from the SPRI report Andre Wrote on ballasted systems)
- A built up roof system generally incorporates insulation in the design of the roofing system because of the multiple layers increasing the insulation properties that can boost the energy efficiency of the system.
How do Built Up Multi-ply roofs provide added protection?
Fire and Uplift Resistance
Built-up roofing systems are tested through Underwriters Laboratories and Factory Mutual Research Corporation to meet very strict fire resistance requirements and ensure adequate uplift resistance under extreme wind conditions.
- Uplift: The built up roof systems continuously adheres each layer to one another forming a monolithic structure with out the need for fasteners. This monolithic layering reduces the number of penetrations and stress points caused by fasteners and increases wind resistance.
- Fire Resistance: FM1 include the highest fire rating available. UL Class A is the best in the industry.
Can an Commercial Built Up Roof be used to meet cool roofing standards and meet Energy Star program requirements?
Yes, multiple options exist to make a black Built Up Roof into a highly reflective or “cool” Built Up Roof:
- A commercial built up roof can be coated with UV reflective material to become a more highly reflective “cool” roof. This is typically done with an aluminum coating to increase the surface reflectivity. A highly reflective white coating can be used but special precautions must be taken to ensure the white coating does not yellow over time due to a phenomenon called bleed-through.
- Commercial built up roof systems can be covered with a white granulated cap sheet to meet cool roofing requirements.
- Ballast may be added—-DETAILS WHY considered cool.
Is a multi-ply Commercial Built Up Roof System economical?
Compared to other high performance commercial roofing systems, built-up roofing is one of the best investments on the market today due to its competitive cost per year of expected service life.
- Low maintenance: Recommended annual inspection to check for clogged drains, gutters, pitch pockets needing to be tipped off, damage caused by a service repairman, etc.
- A multi-ply smooth surface built up roof system can be restored by resurfacing a flood coat of asphalt, a fibered aluminum roof coating, a white or pigmented elastomeric roof coating, and/or asphalt coating and gravel.
- Multiple-ply means fewer headaches, when using the roof as a platform for your vegetative roof, solar array or outdoor living space. The multiple ply provide added protection so there’s no need for expensive deconstruction of items inhabitation the roof to affect repairs like single-plys.
How Can We Help You?
As an industry leader, Culver Roofing Company offers quality built-up roofing systems in Huntsville. We install them with care and expertise. Your roof is such a valuable asset, so choosing a local commercial roofing expert who you trust to partner with, will protect your investment.