PVC Roof Options and Costs for Homes: PVC vs. TPO Roofs 2017

PVC, technically known as Polyvinyl Chloride is really vinyl roofing, though is routinely referenced as PVC roof. It directly competes with TPO and EPDM in the synthetic roof membrane arena, and indirectly with all other roofing materials including BUR, modified bitumen, and structural standing seam roofs designed for lower sloped roofs. The membrane roofs are usually applied to flat roofs, but using them on a sloped roof is possible. Why not just use traditional roofing materials (asphalt shingles or other tiles) on a flat roof? Because they are very likely to leak.

When used with a slope, the overlap of those materials are designed to shed water away from the roof deck. Whereas flat roofs have only a slight pitch, and any standing, or pooling water, could lead to immediate leaks and rotting soon thereafter. PVC membrane is a kind of roofing material that can withstand pooling or standing water — puddles of water that accumulate on roofs with low slopes.

Cost and Values of a PVC Roof

Of the three primary membrane roof types, PVC is the most expensive. EPDM the least, and TPO in the middle. TPO allegedly offers the benefits of both the other types, yet that material keeps undergoing formula changes, and so compared to PVC and EPDM is considered less reliable, particularly when it comes to warranties.

The primary factors that determine the cost of installing a PVC roof are:

  • total coverage area, measured in square feet. For flat roofs, this must include parapets walls and overhangs (which can add 200 to 300 sq.ft.)
  • quality of the installer, which is true with any roofing job, but PVC requires special skills and appropriate tools
  • thickness of the material (see Options below)
  • whether a tear off of previous roof material is needed
  • insulation material
  • slope or pitch of the roof
  • anything else about the roof’s features, like amount of drain pipes, items that penetrate the roof and need flashing or extra attention

Prices for residential installs can vary greatly. A roofer is likely to quote differently than a professional PVC installer, probably less, but also likely to not have the proper tools. A fair range, for 2017, is between $6.00 and $8.50 per sq. ft. if installed by a PVC expert. On the lower end if going with less thick material.

In terms of value, durability and ROI, PVC is arguably the best, or longest lasting of the three. EPDM will go 7 to 15 years before needing replacing or re-coating. TPO is thought to go as long as PVC, but that information is either suspect or unknown for sure just yet. PVC has been in the field for decades and unlike TPO isn’t constantly undergoing changes to the formula to address performance issues. Warranties are usually ‘lifetime’ and with proper installation, it ought to retain solid performance for 20 years or more.

Understanding the Options of a PVC Roof

PVC material is purchased in rolls that are anywhere from 6 to 12 feet wide. Usually when people first consider PVC roofing they think pipe, but those are not the rolls, nor the exact type of material used for roofing. When unrolled on a roof, it forms a membrane, that is single-ply, and is rather flexible. To obtain flexibility, the material has additives. Over time, these additives can break down due to UV rays, but that usually takes decades (20+ years). Whereas TPO is naturally flexible, PVC is not, but can be engineered to be just as flexible and light as TPO.

Between each sheet on the roof are seams, but like TPO, the seams are rectified via air or heat welding. And like TPO, this creates a monolithic roof, that makes it a waterproof barrier on the upper most layer of the home. See this YouTube video as an example of how heat welding works.

The weld is one piece of special equipment that a typical roofing contractor may find unnecessary to purchase if only doing a couple such jobs a year. So, they may forgo this process and overlap seams with glue as the way to obtain a tight seal, which leads to less than 20 years of solid performance.

Attaching PVC rolls to the roof occurs in one of three ways. Most common is mechanically attaching via special metal plates placed over the membrane (in between the seams — before they are welded together) and secured with manufacturer-approved screws. Second most common is via gluing or what is usually called the fully-adhered method. And finally is the ballasted option where river rocks or ballasts are strategically situated to hold it in place.

White is the most common color for vinyl roofing, but not the only. Manufacturers can blend any color in, and thus throughout, the material, so with PVC roofing there are numerous color options. The white and slick surface of PVC makes it fit in with a true cool roof that will reflect a high amount of UV rays, and lead to much cooler roof surface temperatures, and hence significantly less heat transferred indoors on hot summer days.

PVC sheets are produced by spreading the vinyl material, which are typically are reinforced with polyester or glass-fiber mats. Overall, they achieve a thickness between 45 and 90 millimeters. 50 tends to be the norm for residential purpose, but is really a builder preference, or can be made higher by homeowner request and willing to pay for added thickness. PVC roofs have a minimum breaking point of 300 pounds per inch, which makes for above average durability.

One caveatPVC is incompatible with asphalt-based products. If installed anywhere near an asphalt product, a separator sheet must be in place to keep it away from the asphalt. — This is one instance where a TPO membrane would be a more suitable alternative.

Advantages of a PVC Roof

  • proven track record, longer warranties
  • achieves cool roof status, leading to energy efficiency
  • multiple color options
  • highly durable, puncture and tear resistant
  • resists water dampness, algae or fungi build up, and animal fats (from kitchen vents)
  • can withstand high winds / hurricanes
  • fire resistant, is non-combustible
  • little to no ongoing maintenance

Disadvantages of a PVC Roof

  • more expensive than TPO and EPDM roofing
  • takes special expertise to properly install and achieve solid performance
  • the additives that aid in flexibility can break down and pose problems after 20 or so years
  • less eco-friendly than TPO, more eco-friendly than EPDM, it can be recycled with other PVC materials

EPDM Rubber Roof Cost, Pros & Cons: Flat Roof Membrane 2017

Welcome to the default, or old school, material for flat roof installations. It’s technical name: Ethylene Propylene Diene Monomer is a mouthful. While it is simply a rubber material, we’ll go with EPDM since everyone else does. This product competes directly with TPO and PVC as membrane type roofing material. This one though tends to only be used on flat roofs. Some might be wondering why not just use the more traditional roofing materials? Well, those usually come in tile form, and between each tile poses a chance for water to seep in, or pool up, which will lead to rot on the roofing deck. Thus, the membrane approach has been in place for nearly a half century to provide a waterproof barrier.

EPDM Pricing and Value

EPDM is the least expensive of the three primary membrane types, but it isn’t cheap. The material is very durable. Since the early 1960s, EPDM has been the material of choice in canals and other irrigation systems prior to becoming a successful material for waterproofing roofs. It’s estimated to have 1 billion square feet of it installed throughout the world’s roofs. This is partially due to its great durability, it’s ease of installation and it’s great price.

Average Cost Per Sq. Ft. Installed

On the low end, you can plan to spend around $3.00 to $4.00 per sq. ft. for the installation of EPDM rubber on a flat roof. — The low-end pricing, although not very common, would be on par with asphalt shingles pricing, which tells you how affordable it can be. $5.50 to $7.50 per sq. ft. would be the high end, and would likely be a thicker material, or reflective of having the job done by quality flat roof professionals.

What about DIY for EPDM?

The DIY approach is viable, because installation is not complicated. With TPO and PVC roofs, you need special skills and tools for proper installation. With EPDM, you need the sheets, which are sold in as large as 50 feet wide by 200 foot long pieces, some glue and preferably some experience in achieving a successful installation. Home Depot and Lowe’s sell rolls of 10 x 25 feet for around $170 and $205 respectively. Add another $80 for the glue, or bonding adhesive (sold in 3 gallon containers) and $25 for long armed roller and you’re set to go.

When it comes to value or return on investment, that’s another matter. Our Advantages and Disadvantages section below help identify the balance of lasting value vs. known issues. The reality is EPDM roofs last 7 to 15 years on average before needing replacement (less likely) or resealing (more likely). With EPDM liquid roof coating, repairs and resealing can extend the life of the roof and re-institute the waterproof barrier from original installation.

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TPO Roof Cost and Pros & Cons of TPO Membrane Roofs 2017

Say it with me: Thermoplastic polyolefin. Yes, TPO is much easier. According to Firestone Building Products’ white paper, TPO is technically a polypropylene based plastic combined with ethylene/propylene rubber. So plastic and rubber, mixed together basically. Much of the information online boasts how TPO is increasingly popular in commercial roofing. Thing is, we aren’t concerned with commercial buildings, and instead focus on the options available, along with the costs, for adding this material to a residential roof.

Understanding TPO Roof Options

Like all synthetic roofing options, no two companies produce the same formula of TPO. Instead, they alter it just enough to create their own brand. All of it results in a membrane material, between 40 and 100 millimeters thick, which is attached to a roof deck. TPO is known as a single-ply application, meaning one sheet is sufficient to achieve the benefits (see Advantages below). It competes each year directly with EPDM and PVC, which are similar in application with some of the same benefits, but each have their own unique advantages.

TPO is purchased in rolls that are generally 6 to 12 feet wide, and vary in millimeter depth. The typical thickness is in range of 45 to 65 mm, yet is really a builder’s preference that determines the needs for a particular project. Sheets are rolled out, and cut to fit a roof, based on the deck’s dimensions and any objects penetrating the roof structure. The material is attached in one of three ways:

  1. mechanically – nailed or screwed into the deck
  2. fully-adhered – glued
  3. ballasted – after the entire material is spread out, river rocks or ballasts are strategically situated to hold it in place

More often than not, TPO is applied to flat roofs, but not always. Any sloped roof can handle the material. Costs are likely to increase though if applied to a sloped roof.

TPO manufacturers boast the resulting roof will be monolithic, or without noticeable seams. This is wonderful for waterproofing the upper most layer of a home. To achieve this seamless look among various sheets, the actual seams are heat welded together, which is possible given the type of plastic TPO is made of. PVC is another material that is welded at the seams, but with TPO the material is naturally flexible. All roofs need to allow for movement, either from weather / temperature changes or impact by humans walking on it. PVC uses additives to its base material to promote flexibility, while TPO is naturally flexible.

Color options include white, light gray and black reflectivity. It used to be that only white was thought to reflect UV rays, but the material in synthetic roofs (namely a laminated top) can achieve this reflective option.

Cost and Value of TPO Roof

via Atlanta Roofing Specialists

The main thing with effectively estimating the price to install a TPO roof is finding a qualified professional who can do the job. Mechanically attaching the material, or even gluing (fully-adhering the membrane to deck), is something most roofers can probably do. Effectively hot air welding the seams takes care, skill and experience. If this part of the job is done ineffectively, the results (think leaks) will not make the overall value worthwhile.

In our research, RoofingCalc.com lists residential TPO roofing costs at $5.00 to $7.00 per sq. ft. for materials and installation (2017 information), however some commercial contractors will install it for as low as $3.00 to $4.00 per sq. ft., but only on very large commercial flat roofs.

A word of caution needs to be noted. This is touched upon in our Disadvantages below, but needs special mention. Back in 2010, the Midwest Roofing Contractors Association issued an advisory against TPO, which obviously impacted the market. Some of the TPO manufacturers responded to this advisory by noting that no two TPO materials are the same, meaning some brands avoid the problem stated in the advisory. Our take is that TPO is constantly undergoing changes in formula and that is likely a good thing.

The industry is well aware of the perceived problem, yet the flip side is that the material doesn’t necessarily have a proven track record. If looking to go with this material, you are best to stick to companies who’ve been in it since the beginning (read as before the year 2000), to ensure the warranty will stand up. Usually warranties for TPO roofs are a minimum of 10 years, and as much as 25 years. The material itself ought to last much longer, so installation is the ongoing issue and how seaming is handled.

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