All About The Roofers Daily

All Type Roofing Lancaster PA

Nov 25

What is a Membrane roof and how does it work?

Membrane roofing is a type that provides a continuous, watertight barrier to protect a building’s interior. Because membrane roofs are watertight, they are often used as flat roofing. This is because they can withstand water evaporation. They can be used for roofs with low pitches, were tiled, slate or shingled roofing might not be effective.

Installing a Single-Ply Membrane to a Flat Roof is in Progress

The substructure is made of wood, concrete, or metal and is located below the main roofing layers. It also includes insulation, plywood, underlays, and vapor barriers. These are all installed by all type roofing lancaster pa.

  • Membranes for Built-Up Roofs (BUR).

For decades, built-up roof membranes (abbreviated as BUR) have been successfully used on flat roofs. Although single-ply roofing is becoming more popular, BURs are still in demand.

BURs are made up of layers of bitumen, coal tar, and reinforcing material sheets. They are also known as Tar and Gravel Roofs. A ply is a name for each layer. Depending on the roofing conditions and other characteristics, there may be multiple plies.

The reinforcing feels are sprayed with bitumen to infuse the sheets. The felt rolls measure 3'-0", with each layer being overlapped in a variable amount according to manufacturer instructions. More overlap is needed at roof transitions and roof margins. However, less overlap is required throughout the main roof surface.

  • Modified Bituminous Membrane Roofing

Modified bitumen roof membranes are also known as polymer-modified roof membranes. They have been used since the 1960s to replace older roof systems. Installation is made easier by the fact that both the bitumen binder (and reinforcing fabric) are packaged together in a single roll.

As the name suggests, polymer-modified bitumen roofing materials contain bitumen additives that make the bitumen stronger, flexible, or more resistant to heat. It is important to select the right type of modified bitumen roofing membrane for your job. The manufacturer should give architects guidance on which product they should specify.

To ensure water tightness, modified bitumen roofs (such as BUR roofs) are typically constructed in multiple layers (typically two to three layers). A base sheet is attached to the roof using either mechanical fastening or glue. The final layer is then added. In three-ply applications, the foundation sheet is laid first. The reinforcing plywood is followed by the sheet.

Modified bituminous roofs, as opposed to BUR, have a simpler installation process that is less susceptible to problems. However, installers should ensure that the roll has been properly heated before being rolled down. These products are also available for many decades. They can be fitted properly and are extremely durable.

Modified bitumen systems like BURs are dangerous for the environment and workers because of the chemicals used. Even though torch-applied Tar has a less unpleasant odor than hot-mopped Tar, the vapors can still be harmful.

  • Modified SBS Roof Membrane Bitumen

In their completed state, styrene-butadiene-styrene (SBS) membranes are more flexible (elastic). SBS membranes can also be used with hot-mopped Asphalt, similar to BUR membranes. There are also new adhesive-backed, peel-and-stick roofing products.

SBR membranes are also known as styrene-butadiene rubber membranes. If you refer to a "rubber roof", some may be referring to a modified bitumen roof (SBR) while others may be referring to a single-ply EPDM roofing, which we will cover further.

  • Modified Bitumen Roof Roll with Torch Application

Thermoplastic is one type of thermoplastic.

Single-ply membrane roofs consist of large sheets of material, which are connected together to form one continuous membrane. To avoid leaks, there is only one layer of weathertight material. It is important to properly install seams, transitions, and penetrations. These single-ply methods are common on commercial flat roofs.

A single-ply membrane that is properly installed and maintained can last for more than 30 years if seams are regularly inspected and repaired. The thickness of the membrane also plays a role in longevity. Thicker membranes can last longer but are more costly. Roofs can be damaged by extreme weather and should slope towards roof drains. It is also important that any ponded water be removed from flat roofs within 48 hours.

Roof with fully adhered single-ply membrane

Mechanically attached membranes are directly attached to the substrate. They offer uplift resistance and are less prone to leaks. In most cases, a disc or batten-bar fastener penetrates the membrane. A welded patch seals it. For certain membrane types, non-penetrating fasteners may also be available. To ensure that penetrations are sealed properly, installers must exercise extreme caution.