How long does a Johns Manville roof last?

As general industry figures, well-maintained TPO and EPDM roofs commonly last 20 to 30 years or more. Installation quality, drainage and maintenance make a big difference.

Does better insulation lower energy costs?

Adding insulation raises the R-value of the roof and reduces heat moving through it. How much that saves depends on the building, the existing insulation and how the building is heated and cooled.

What is tapered insulation and why does it matter?

Tapered insulation is cut with a slight slope to move water to drains and scuppers. It helps prevent ponding water, which shortens membrane life.

Can a Johns Manville roof be installed over an existing roof?

Sometimes. If the existing roof and deck are sound and dry, a recover may be possible. Wet insulation or deck damage usually means a tear-off. We check during the assessment.

Johns Manville Roofing Systems

TPO, EPDM and insulation for commercial buildings in Indianapolis and Central Indiana

Get a Free Estimate Call (317) 707-6637

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Johns Manville makes TPO and EPDM roofing membranes along with the insulation underneath them, including polyiso and tapered insulation. SPG Roofing & Exteriors installs and repairs TPO and EPDM roofs as part of our commercial roofing work across Central Indiana. This page explains the Johns Manville system and what to ask before you choose it.

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Brands We Work With

We install systems and products from leading manufacturers.

Systems We Install

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Johns Manville TPO and EPDM

TPO is usually white and reflective, with heat-welded seams, and is the system we quote most often on commercial flat roofs. EPDM is a rubber membrane, usually black, with taped or adhered seams. See TPO roofing and EPDM roofing for how they compare.

Insulation and Tapered Systems

The insulation under a flat roof matters as much as the membrane. Polyiso insulation adds R-value to the roof assembly. Tapered insulation is cut with a slight slope to move water toward drains and scuppers, which helps prevent ponding, one of the most common causes of early membrane failure. When we replace a commercial roof, we check whether the insulation is wet and whether the roof drains properly before we recommend a system.

Commercial roof insulation and membrane installation

Warranties

Johns Manville's commercial roofing guarantees are issued under its Peak Advantage program. Like all manufacturer warranties, the terms, length and eligibility depend on the system, the project and the installing contractor, and many require an inspection by the manufacturer after installation. Before you sign, ask any contractor which manufacturer warranty they can provide for your roof and get it in writing. We will tell you up front which warranty options are available for your project.

Why Choose SPG

Key Benefits

TPO Membranes

White, reflective single-ply membranes with heat-welded seams.

EPDM Membranes

Rubber membranes with a long track record on commercial roofs.

Polyiso Insulation

Rigid insulation under the membrane adds R-value to the roof assembly.

Tapered Insulation

Sloped insulation moves water to drains and helps prevent ponding.

Our Process

How It Works

From first call to final walkthrough — here's what to expect.

Roof Assessment

We inspect the roof, photograph its condition, and check membrane, seams, flashings, insulation and drainage.

System Recommendation

We recommend TPO, EPDM or a repair, with tapered insulation where drainage needs it, and explain the warranty options.

Installation

The deck is prepared, insulation is installed, and the membrane is installed following the manufacturer's installation requirements.

Closeout

We do a final walkthrough and you receive the warranty documents for your system and maintenance recommendations.

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What Our Customers Say

Forest B.

“SPG is my go-to roofing company. As a commercial real estate broker with many options for roofing companies, Dustin is always my first call when I need a roof checked on. I have had him hop on many roofs between my personal rentals and countless clients. They are always professional, competitively priced, and very responsive. I highly recommend SPG for any residential or commercial roofing needs.”

Lindsey S.

“I’ve been really impressed with SPG Roofing & Exteriors and the level of professionalism they show on every project. The communication is clear, scheduling is smooth, and the quality of work speaks for itself. Everyone I’ve interacted with has been friendly, knowledgeable, and easy to work with. I’d definitely recommend them to anyone looking for reliable roofing and exterior work.”

Rhonda R.

“Chris Sheets showed up at my home and was a breath of fresh air with his professional demeanor after the horrible HVAC installation I experienced. Chris walked my home to visually inspect the install and the damage done and gave a quote with detailed explanation of what he said needed to be done to resolve the issues, starting with the roof where the furnace jack was installed incorrectly causing water damage. He was very detailed as he walked my entire roof to find any issues and has resolved them all at this time. I would recommend SPG, as Cameron was very helpful also. Job well done, SPG Roofing!”