The Advantages of Adhered Single Ply Roofing Systems

Guide to JM Adhered Single-Ply Roofing Systems.

The Adhesives.

The Advantages.

The App. 

Q: Why adhere a roofing membrane (with adhesive) instead of attaching it (with screws)?

A: Each approach has its pros and cons. In this article, we look closely at the adhered approach and the applications where those products can be utilized for optimal results.   

Watch the 20 minute webinar below.

INTRODUCTION

This quick-and-easy training guide compares the different types of Johns Manville adhesive roofing products and highlights key considerations for installation of each. Also included is an introduction to the JM Roof Techxpert app,which helps you manage changing environmental conditions during installation at the jobsite.

1. First, we’ll take a brief look at the adhesives and the jargon.
2. Then, we’ll talk tips, specs and watch points.
3. And last, we’ll spotlight our app as way to navigate local weather.

The Adhesives

Johns Manville adhesives accommodate a great array of roofing substrates and situations, including those involving tight workspaces, tight timelines or weather. When using TPO, PVC, EPDM, fleece-backed membranes or self-adhered products, there is a corresponding JM adhesive solution to fulfill your roofing needs.

Johns Manville roofing adhesives – summary of product composition and usage:

Solvent (for TPO or EPDM)

• Two-sided application
• Synthetic polymer based

Low VOC (for PVC)

• Two-sided application
• Synthetic polymer based

Foam (for fleece-backed membranes)

• One-sided application
• JM Roofing System Urethane Adhesive (RSUA)

Self-adhered (TPO membrane)

• One-sided pre-applied factory release liner
• 60 mil

Water-based (products for TPO, EPDM or PVC)

• One-sided application (two-sided for vertical applications)
• For TPO and PVC, color change indicates ready-to-adhere

Sprayable (for TPO and EPDM)

• Two-sided application
• Low VOC sprayable aerosol

The Advantages

Check out the following advantages and benefits of each adhesive in specific situations and also note some watch points within those same scenarios. Refer to the product data sheets on www.jm.com for specific product attributes.

JM SOLVENT & LOW VOC ADHESIVE

Packaging and Application: Five-gallon pails, roll-on application (spray and better spreaders are optional), two-sided contact for EPDM, TPO and PVC.

Our solvent and low-VOC adhesives represent a tried-and-true method with relatively low equipment and maintenance costs. The product is rolled on as a two-sided contact cement – applied to the substrate as well as the membrane (spray and better spreaders are optional). After flashing off, the two sides are mated together. Plus, its green strength is advantageous for vertical surfaces.

Benefits

• Longstanding, reliable industry performance
• High wind performance
• Advantageous green strength (for vertical or curved flashing)
• Low equipment and maintenance costs

Watch Points

• Odor (a consideration if structure is occupied)
• Flash time varies depending on ambient temperature and conditions (navigate the environmental conditions)
• Blistering (can occur if flash time is mismanaged)

JM FOAM ADHESIVES

Packaging and Application (JM Roofing System Urethane Adhesive (RSUA)): Cartridges, bag in a box, tote or drum for fleece-backed membranes applied by either spray, splatter or bead.

JM foam adhesives are only used when installing fleece-backed roofing membranes or insulation boards. They have a wide range of temperatures and conditions where they can be applied – and where flash time is fast so the install can move right along at an efficient clip. On that note, the product is exothermic – drying faster in high temperatures – so a hot summer day requires greater attention to flash time.

Benefits

• No odor 
• Fast flash-off (3 to 6 minutes)
• Wide temperature range (25F and rising)
• Increased hail performance (foam with fleece membrane)

Watch Points

• Short open time (caution on hot days)
• Fleece-backed membrane only

JM SELF-ADHERED MEMBRANES

Packaging and Application: Rolls of 10' or TPO SA, peel-and-stick application, broom-and-roll install.

Our self-adhered membranes already have adhesive in place, so they install fast, with little mess, no odor, and less user input regarding flash time or physical spreading of adhesive (avoids uneven application and blistering, for example). Simply remove the release liner, mate it to the substrate and weld the seams.

Benefits

• Fast install
• No odor
• Less user input (factory pre-applied adhesive, even and consistent)
• Clean (no liquid adhesives)

Watch Points

• Cold temp (primer required between 20 to 40F)
• Shelf life is 12 months 
• 10' max width

JM WATER-BASED ADHESIVES

Packaging and Application: Five-gallon pails, roll-on application (spray and better spreaders are optional), one-sided contact for EPDM, TPO and PVC (two-sided for vertical).

JM water-based adhesives are available for EPDM, TPO and PVC membranes. Easy-to-use, roll-on applications have no flash time, low odor, and they offer substantially greater coverage per gallon (versus solvent-based) as well as substantially less installation time (no flash-off considerations). One-sided contact for horizontal and two-sided for vertical.  

Benefits

• Fast install (50% reduction in application time)
• Low odor
• VOC compliant or LVOC compliant
• Low equipment and maintenance costs
• 2.5X coverage compared to Solvents/Low VOC

Watch Points

• Temperature above freezing (40F and rising for Water-based)
• Humidity (when higher, longer cure time) 

JM ALL-SEASON SPRAYABLE ADHESIVES

Packaging and Application: 45# canister, spray application, for smooth-backed EPDM and TPO, one-sided contact as a primer for self-adhering (SA), two-sided contact for single-ply and fleece-backed (FB) membranes. 

Our sprayable adhesives are highly efficient – quick flash-off in tandem with consistent application means they go on faster, with better coverage than 2-sided, rolled-on products. They’re flexible too – working with smooth-backed EPDM as well as TPO, effective through a great range of temperatures during application and VOC compliant in all 50 states. Plus, we offer a full-line of accessories to keep you up to speed (spray guns, wands, nozzles, hoses, canister blankets).  

Benefits

• Fast install (cover more area, more efficiently)
• Low cost (30% faster than roller)
• Low VOC compliant
• Quick flash-off
• Easy clean-up (not a lot of drips and runs)
• Spray-coverage consistency

Watch Points

• Adhesive container temperature (canister blankets maintain temp at 60F to 80F)
• Maintenance of application equipment

The App

The JM RoofTech Xpert App helps you manage changing environmental conditions at the jobsite.

Those conditions include:

–Temperature –Relative humidity –Dew point –Wind –Sun and cloud exposure

As we’ve highlighted, each adhesive has certain benefits as well as watch points, some of which are related to the changing climate throughout any given day. For example, humidity is more of a factor with water-based products whereas heat is more of a factor with exothermic (foam) products.

How to Use the App

Example A

In this example (Figure 1, phone-screen image), we’re applying a pail-based solvent for TPO and EPDM. The JM RoofTech app has automatically identified our geolocation and provided readings such as temperature, dew point and wind speed at the jobsite.

The temperature is 54F and the dew point is 34F. The dew point is the temp where the air can no longer absorb water and things get wet.

So, the 20-degree difference is good – plenty of leeway if the temp starts dropping. Therefore, the green light by dew point indicates favorable conditions for application, with the adhesive’s flash time estimated at a reasonable 15 to 30 minutes.

Wind speed is another factor displayed, indicated with a yellow light as cautionary in this example but OK to proceed.

A red light by any key factor will indicate conditions not suitable for installation.

Example B

Here (Figure 2, dual phone-screen image), we’re showing what happens with a different job but now under changing conditions throughout a particular day. At the very base of the screen on the left there’s a ribbon showing time of day as 9 a.m. and on the screen to the right it’s 1 p.m., both times highlighted in blue.

In the morning (left screen), the dew point is only separated from the temperature by 14F degrees. And the considerable flash time is estimated at up to 40 minutes. However, in the afternoon (right screen), temperature, dew point and flash time are more favorable.

This data helps parcel out the day. For example, use the morning to do the tear-off, get the insulation fastened down and line-up the membrane. Then, in the afternoon, apply adhesive and install the membrane. Or, if starting adhesive work in the a.m., at least recognize that it will proceed more gradually early in the day (install areas that require more time and attention in the morning), yet it will go faster later on (install wide-open areas in the afternoon where a crew can really make good time).

SUMMARY

Johns Manville offers a host of adhesive products that improve quality while overcoming challenges on the jobsite – helping you navigate environmental conditions, compliance and high penetrations within single-ply roofing applications.

Reasons why for adhered roofing…

Lasts Longer (less stress on the membrane, reduced flutter, tough against wind and hail).

Looks Better (sealed down tightly and consistently, smooth and flat, no fastener penetrations).

Works Harder (less opportunity for leaks, advantageous for high penetrations and tight spaces).

• Extended guarantees (25- and 30-year)
• Enhanced wind performance (wind riders)
• Enhanced hail performance (hail riders)
• Non-penetrating
• Reduced flutter
• Visual appearance

DISCLAIMER FOR ARTICLE

Actual on-site conditions may differ materially from those assumed here, therefore, please consult with your design/engineer professional for information and recommendations. All data and other information) presented in this article are not warranted as to completeness and are subject to change without notice. Johns Manville disclaims any responsibility or liability to the fullest extent permitted by applicable law, whether in contract, tort (including, without limitation, negligence), equity or otherwise, for any loss or damage arising from any reliance on or the use of this material in any way. The information contained herein is provided as a courtesy for general educational purposes and as of the date and time referenced only, and Johns Manville does not undertake any obligation to update such information.

Certain restrictions apply, see JM Roof Techxpert for additional terms and conditions.