Comparing Commercial Roofs

Cartoon character Homer Simpson may think facts are meaningless, but any facilities manager or commercial property manager makes sound business decisions from facts, not feelings. If you are tasked to compare thermoplastic olefin (TPO) membrane and polyvinyl chloride (PVC) roofing, you need facts about two complex materials.

Pros and Cons of TPO and PVC Roofing

Both TPO and PVC are excellent commercial roofing products. TPO is as durable as PVC (in some tests it outperforms PVC), but has a slightly lower installed cost per square foot. The level of quality you choose determines the amount of filler used with a TPO roof, which is essentially a natural product (rubber) combined with petroleum products. Binders, colorants and stabilizers are added for strength and longevity.
PVC roofing is more flexible than TPO, so complicated roofs will install faster and with greater water resistance using PVC scrim than TPO membrane. In harsh environments, PVC is superior to TPO for chemical resistance and UV chemical breakdown.

What are These Roofing Materials Made of?

Both thermoplastic olefin (TPO) membrane and polyvinyl chloride (PVC) begin life as natural materials. TPO is based on a type of rubber and ethylene, an organic gas. PVC is made from petroleum and salt.
TPO is in the thermoplastic elastomer family. Its membranes bond ethylene propylene rubber and polypropylene together, then add filler materials to create the finished roofing membrane of the desired color.
Both are thermoplastic elastomers. Both require only single membranes, making them quicker to install and easier to maintain than BUR or EPDM roofing.
PVC has been around many more years than TPO and has stood the test of time as one of the most durable, toughest roofs for commercial application.

Installation

Both roofing materials use hot air-welded seams. Both are lightweight and install in strips. PVC is slightly more workable than TPO, meaning it will fit in around complex shapes readily. Both methods require well-trained crews for proper installation.

Maintenance

Maintenance needs for both products are similar. Minimal upkeep is required, with regular (at least annually) inspections to check for seam damage, ponding, and mechanical fastener integrity.

Whether you feel TPO is tried-and-true, or lean toward PVC as the roof you need, PSI Roofing is your dependable, proven leader in commercial roofing. Contact PSI Roofing today so we can help you understand which method, TPO or PVC, is best for you.

Comparing Commercial Roofs: Built Up and Metal

Built-up roofing (BUR) and metal roofing are two of the oldest methods of securing a commercial building from the elements. Both have long outlasted any tests of time the industry could concoct; both have proven themselves as economical, durable ways of protecting your company’s most valuable asset, its building.

Pros and Cons

BUR roofing is a simple method that is labor intensive but produces fine waterproofing results. Think of them as the classic “tar and gravel” roof, because the layers are straightforward and time-honored:

  1. Mechanically fastened bottom ply
  2. Tar, asphalt, or glue to adhere a felt layer over the bottom ply
  3. A third layer, the cap sheet, goes over the first two
  4. A final layer of asphalt and crushed stone, or ballast, holds everything in place

Metal roofing uses fewer layers but, for most steep-slope applications, is superior to BUR. It is mechanically adhered, usually involves a waterproof membrane, and provides excellent energy efficiency through spray coatings and reflectivity.

BUR is easily repaired for many years. It can be spot repaired, meaning you need not consider an entire re-roof because one area is failing. Metal roofing requires almost no maintenance, but can eventually show corrosion or rust.

Composition

Metal roofing can be made with steel, tin, aluminum, or natural metals like iron and copper. Metal roofing usually has baked-on color and protective finishes.

BUR uses earthy materials: tar or asphalt, crushed stone, organically derived mats. You can have stronger materials incorporated in the plies, such as fiberglass, for added strength.

Durability

Both systems are extremely durable, but few roofing materials can touch metal roofing’s lifespan. Fifty-year roofs are common, with minimal repair and maintenance. BUR roofs have been known to last 40 years.

Maintenance

Due to the (comparatively) inexpensive materials in BUR, expect to compensate for the inexpensive installation with regular maintenance. Twice a year, get your commercial roofer to inspect and catalog any issues with your company’s BUR roof. Expect increased maintenance and patching the longer the roof lasts.

Metal roofing will need cleaning to increase reflectivity and ensure water does not corrode fasteners. It requires very little monitoring.

Consult Experts

If your company is budget-conscious, you have many options for a re-roof or new roof. Consult your local, dependable commercial roofing experts, PSI Roofing, to help with selecting between BUR, metal, or another roofing method. Contact PSI Roofing today to speak with a company that puts integrity first.