What is PVC and TPO Rolled Roofing?
The principal purpose of any roof is to protect the people and the objects inside the structure. Every roof has its unique challenges when laying out rolled roofing membrane. Good estimators, PVC roofing contractors and crews, and roof system designers are skilled at laying the membrane sheets, avoiding waste.
Noah’s Roofing Contractors have over 20 years as rolled roofing contractors in the Sacramento, Roseville, El Dorado Hills, Elk Grove, Cameron Park, Carmichael, Fair Oaks, Davis communities.
By knowing the pros and cons of TPO and PVC, you avoid the risk of purchasing a roofing system unsuitable for your specific needs. Although the membranes appear to be the same, TPO and PVC roofing systems are significantly different.
This article will explain the differences in performance, composition, and durability of TPO and PVC roofing systems.
PVC and TPO Roof Differences
If you are considering replacing your commercial roof, PVC and TPO roofing systems are great options.
Understanding how TPO and PVC membranes differ will help you decide the most suitable roofing system for your commercial building. If you do not consider your building’s specific needs and which roofing system would best meet those needs, you run the risk of making a capital investment on a roofing system that is likely to fail prematurely.
PVC–(Polyvinyl Chloride) – This membrane comprises ethylene and chlorine, derived from processed petroleum or natural gas and salt, respectively. A polyester reinforcement sheet sandwiches two PVC plies. Included in the manufacturing of PVC plies are:
- Biocides (help deter algae, bacteria, insects, mold, and rodents)
- Fiberglass or polyester reinforcement Color pigments
- Color pigments
- Ultra-violet light inhibitors
TPO–(Thermoplastic Polyolefin) – to produce the TPO membrane, manufacturers will polymerize ethylene-propylene rubber and polypropylene. The following are used in the production of TPO roofing materials:
- Color pigments
- Fiberglass
- Talc
- Ultra-violet light inhibitors
Comparing PVC to TPO Rolled Roofing
- Both types of rolled roofing may be installed with a bonding adhesive or mechanically installed with special screws and plates.
- Both types of roofing systems require the seams to be heat-welded.
- Heated-air welded seams help PVC and TPO Roofing remain watertight under a variety of weather conditions.
- TPO roofing systems demonstrate superior results for the break and tear strengths
- PVC outperformed in fire resistance, chemical resistance, and overall cost. (Buildings with grease traps on the roof would be better served with a PVC roofing system.)
- PVC is priced similar to other low slope roof options, sometimes cheaper than TPO.
- PVC and TP roofing materials are recyclable.
Pros and Cons of PVC Rolled Roofing
Pros
PVC is a lightweight single-ply roofing system–multiple layers of the PVC membrane are unnecessary. While asphalt shingles weigh about 150-240 lbs per square, PVC weighs 51lbs per square.
PVC roofing materials come in a variety of colors, from white to tans to grays. Its UV resistance qualities combined with the most reflective colors save you money by lowering your cooling costs; it also helps reduce the “heat island effect” that occurs in urban areas.
PVC roofing systems not only meet Class A fire rating requirements, but their special chemicals also allow them to self-extinguish. Additionally, PVC comes in different thicknesses, ranging from 40-80 mils, giving consumers more options.
PVC has a Class 4 Hail damage rating withstanding a simulated 2-inch sized hail test and is very resistant to tears and punctures. Its chemical resistance properties were impervious against oil and grease, making it ideal for restaurants and buildings with grease traps on their roof.
Repairs to a PVC roofing system are simple, requiring a roller and heat welder for most repairs. It would serve you best to hire the professional rolled roofing contractors at Noah’s Roofing to perform such maintenance and have the work performed under warranty.
PVC’s wind resistance has shown to withstanding CAT 3 hurricanes, wind speeds between 110 mph to 130 mph. PVC has an average lifespan of 20 – 30 years, similar to asphalt shingles. It also exceeded the ASTM standard of break strength of 200lbs per square inch, receiving a rating of over 300lbs per square inch.
Some commercial roofing companies and contractors prefer to use PVC over TPO due to its flexibility characteristics. It can be installed year-round provided the temperature remains above -58° F, and the heat welder can get the temperature of the PVC membrane up to about 1094°F to seal correctly.
Cons:
PVC requires a clean, smooth surface to be installed correctly; a membrane punctured by debris can develop leaks. The old roof will need to be entirely removed before a new PVC roofing system can be installed. This extra time increases labor costs.
PVC does not perform well in bitterly cold environments, becoming brittle; it will crack or shatter if walked upon, rendering it useless. The temperature range for PVC is -58° F (-50° C) up to 347° F (175° C).
PVC releases toxic chemicals if burned and during the manufacturing process. The most harmful chemical, dioxin, can cause reproductive and developmental problems, change hormones, cause cancer, and damage the immune system.
Pros and Cons of TPO rolled roofing
Over the past two decades, U.S. manufactured TPO (Thermoplastic Polyolefin) has become one of the most installed low-slope, single-ply roof membranes due to its low price point. A recent study of EverGuard TPO roofs installed 8-16yrs ago showed that they all exceeded ASTM standards for newly manufactured TPO.
Pros
TPO rolled roofing systems are both durable and robust. TPO has demonstrated exceptional weathering and tear and break resistance. Installing or repairing a TPO rolled roofing can be a significant project. Facility managers/owners can choose from a few types of insulation options the :
- Polyisocyanurate (Polyiso) – This is the most commonly used insulation type for roofing applications; Polyiso is more expensive but provides a high R-value rating.
- Extruded Polystyrene (XPS) – Defined by the green, blue, or pink color, Extruded Polystyrene falls between EPS and Polyiso in performance and price range.
- Expanded Polystyrene (EPS) – Provides the highest R-value; EPS is used for roof, wall and floor insulation. EPS can also be used for ground contact and does not retain water over time.
TPO is Class A fire-resistant- fire retardant chemicals are added to the material during production.
Reflective and Penetrable – Most TPO is white and highly reflective.
A TPO will last approximately 15-20 years. During this time, seams can rip apart, and flashings can fail, the membrane can become punctured, etc., which will cause a roof leak. With regular inspections and proper maintenance, leaks can be prevented, and the roofing system lifespan can be extended to last as long as 30 years.
Cons
TPO is comparatively inexpensive. TPO products are quite different in construction and quality. Despite the many different thicknesses available, they all deteriorate and weaken at approximately the same rate.
Over the years, the compounds in TPO have changed, making it challenging to determine precisely how long a single-ply TPO roof will last. The limited durability appears to be inherent to the laminating process, producing weak spots that cause disintegration, splitting and surface cracking and splitting.
Another problem with TPO is that rolls tend to be small in width, creating issues with additional seams; the extra seams cause difficulties with membrane contractions and expansion, creating loose seams and water penetration.
PVC vs. TPO – Warranties
In purchasing either a TPO or PVC roofing system, there are two warranties to consider. The coverage and duration of the warranties depend on the roofing system manufacturer and the rolled roofing contractor.
- The manufacturer’s warranty—This warranty covers any manufacturing defects of the roofing materials.
- The roofing contractor’s warranty—to cover his workmanship, your roofing contractor provides this warranty. This warranty includes everything covered and what actions void the warranty.
These warranty coverages and duration depend on the roofing system manufacturer and the rolled roofing contractor, with no clear advantage for PVC or TPO.
Our team takes great satisfaction on the thousands of excellent roofing systems we’ve built over the years. Each of them is energy-efficient and designed to suit the specific needs of our clients. Because we deliver personalized services, we always meet the expectations of the people we work with.
WORK WITH US
From roof replacement to repairs, Noah’s Roofing has you covered. If you are located in the Sacramento, Roseville, El Dorado Hills, Elk Grove, Cameron Park, Carmichael, Fair Oaks, or Davis communities, our team can perform a multi-point roof inspection that helps us determine the current and potential roofing problems that you might encounter. Contact us today! We provide free estimates.
