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10-29-2009. Self-Adhesive Roof Membranes. Characteristics common to all SA membranesSelf-Adhesive: not self-adheringWe've yet to see a roll adhere itself to anything. 10-29-2009. Self-Adhesive Roof Membranes. Characteristics common to all SA membranesSelf-Adhesive: not self-adheringWe've yet to see a roll adhere itself to anythingShould be termed PSA (pressure sensitive adhesive) membranesPressure must be applied to ensure complete and watertight bonds.
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10-29-2009 Self-Adhesive Roof Membranes
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10-29-2009 Self-Adhesive Roof Membranes Characteristics common to all SA membranes
Self-Adhesive: not self-adhering
Weve yet to see a roll adhere itself to anything
Should be termed PSA (pressure sensitive adhesive) membranes
Pressure must be applied to ensure complete and watertight bonds
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10-29-2009 Self-Adhesive Roof Membranes Characteristics common to all SA membranes
Self-Adhesive: not self-adhering
Weve yet to see a roll adhere itself to anything
Should be termed PSA (pressure sensitive adhesive) membranes
Pressure must be applied to ensure complete and watertight bonds
Requires some finesse compared with traditional application methods
These arent your fathers hot mot mopped or welded systems
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10-29-2009 WHY Self-Adhesive Membranes? Advantages
no adhesive to apply no buckets to dispose of
no open dry time & less set-up time
reduced solvents/fumes & no hot asphalt
consistent/uniform application of adhesive
techniques arent radically different
details familiar either the same or very similar
crew size may be reduced
speedy application
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10-29-2009 WHERE Do Self-Adhesive Membranes Make Sense? Where open flames are not allowed
Where solvent or asphalt fumes may be an issue
Where you cant set-up for hot asphalt, but want an asphaltic system
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10-29-2009 WHERE Do Self-Adhesive Membranes Make Sense? Where a mechanically attached system wont work you cant penetrate the deck
When you have a weight limitation
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10-29-2009 WHEN are Self-Adhesive Membranes NOT a Good Idea? Ponding water, anyone?
Steep slope, no ability to fasten
Cold (or cool) weather?
Dirty, messy tear-off cant quarantine or separate the roofing application
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10-29-2009 Some General Considerations Be sure to store properly out of direct sunlight
Do not use if membrane is not tacky to the touch (SA has a shelf life)
Be sure to have adequate slope and drainage
Dont interfere with ventilation needs of the building they can form a vapor barrier
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10-29-2009 Additional Considerations Substrate must be:
clean
dry
free of dust, dirt, oils, etc
may need priming
Perform a tape test with masking tape to confirm substrates condition
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10-29-2009 Additional Considerations
Without liquid bitumen (hot asphalt, torch, bonding or cold adhesive) to fill surface irregularities it is critical to pay attention to laps and t-joints
SA sheets are pressure sensitive and should be treated as such.
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10-29-2009 Additional Considerations Be sure to follow mfrs temperature recommendations cool weather will affect how well they adhere
At temperatures below 50oF special precautions should be followed especially if there is no sun
The ambient temperature, substrate temperature, and membrane temperature must all be considered.
Artificial heating, e.g., hot air may be employed to ensure adhesion at low temperature
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10-29-2009 What Types of Products Are Available? Asphaltic membranes
Steep-slope ice damming membranes
Low Slope Systems
Single ply membranes
TPO
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10-29-2009 Self-Adhesive + Low Slope
Combines the historical performance of modified bitumen compounds with addition of a self-adhesive layer for ease of application, however..
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10-29-2009 Self-Adhesive + Low Slope There are basic differences between steep and low slope applications.
Steep slope products are typically used as underlayment, and function as secondary moisture protection
Low slope products must be waterproof when they are installed
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10-29-2009 Specifically for Asphaltic Membranes Base/inter plies
self-adhesive w/release film or paper
various surfacing options (sand, film, SA, .)
some are suitable for mechanical attachment
reinforced with either fiberglass, polyester, or a combination of the two
Cap sheets
self-adhesive w/release film or paper
typically granule surfaced or other opaque surfacing
reinforced with either fiberglass, polyester, or a combination of the two
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10-29-2009 Self-Adhesive Roof System Main Point: Take a look at the MA (Mechanically Attached) liberty system.
What to say: Cold Applied system breakdown- this is over a wood deck.
May want to make note you eliminate torches and kettles over wood decks!
Remember with an MA base you dont need to prime the plywood. This diagram shows a 3 ply liberty system.
MA base sheet, SA (self adhered) interply and a granular cap sheet.
Slide Summary: The mechanically attached Liberty system is great in areas where you may need to remove the membrane at a later date.
Main Point: Take a look at the MA (Mechanically Attached) liberty system.
What to say: Cold Applied system breakdown- this is over a wood deck.
May want to make note you eliminate torches and kettles over wood decks!
Remember with an MA base you dont need to prime the plywood. This diagram shows a 3 ply liberty system.
MA base sheet, SA (self adhered) interply and a granular cap sheet.
Slide Summary: The mechanically attached Liberty system is great in areas where you may need to remove the membrane at a later date.
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10-29-2009 SA base plies with heat welded (HW) cap sheets offer added protection for torch applications.
Combustible materials and hidden areas of negative air pressure are covered by the SA material. See CERTA guidelines.
SA base plies with heat welded cap sheets also extend the application window for SA sheets in cool conditions.
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10-29-2009 Self-Adhesive TPO Membranes Using traditional smooth back membranes as the backbone45, 60, 80 mil
Its the same sheet that provides the waterproofing and weathering layer
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10-29-2009 Self-Adhesive TPO Membranes? What Stays the Same? Everything plus adhesive
Reflectivity its still Energy Star, meets Title 24
Puncture resistance
Tear resistance
Cold flex
Breaking strength/elongation at break
Dimensional stability
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10-29-2009 TOP 10 LIST Helene and Tims Top 10 List
(well almost 10)
What NOT To Do!
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10-29-2009 Avoid Improper Insulation Attachment
Fasteners not set properly, backing out
Dirt and Debris on Substrate
Affects ability to adhere
Moisture on Substrate (even morning dew or that light mist on a foggy morning)
Affects ability to adhere
Low Temperatures During Installation (just because there wasnt ice on the rolls)
Requires warming rolls, tacky primers, or heating if necessary
Misalignment of Sheet
Can short the lap width especially with membranes that dont have a granule selvedge
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10-29-2009 Not Properly Rolling In the Membrane/Using Wrong Roller (or none ewww)
Can affect adhesion to the substrate
Mis-Identifying T-Joint Locations
Use of a 45 degree cut greatly reduces problem
Improper Wall Flashing Heights
Both too low and too high follow mfrs recommendations
Absence of Primer
Critical to adhesion, especially on walls and membrane
Avoid
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10-29-2009 Where Should Care Be Taken? What are acceptable substrates?
How should the lap area be cleaned?
What about priming of the laps?
Weather conditions >45 or 50F typically.
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10-29-2009 Where Should Care Be Taken? Placement of the membrane
if heat weldable grademake sure the lap is placed correctly
Self-adhering laps may be larger can reduce area covered by ~5%
Is cut edge sealant recommended? What about sealant along the underside side laps?
How should endlaps be made?
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10-29-2009 Where Should Care Be Taken? Remember, repositioning of the membrane is difficult at best impossible at worst check sheet position before removing release film
Sheet to sheet adhesion cut out & replace (you want this stuff to be sticky)
Keep paper, debris, release film, dirt, etc. from getting into the system
Follow mfrs recommendations regarding rolling of membrane/laps
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10-29-2009 And You Were Wondering Wheres the Data?
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10-29-2009 For TPO, Same Story, Different Day About cleaning on self-adhering laps
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10-29-2009 In Summary Consider System Advantages No (or min. amount) adhesive to apply
Always correct, consistent/uniform application of adhesive
No buckets to dispose of
Less staging area
No open dry time or set-up time
No need to wait for solvent to flash off
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10-29-2009 In Summary Consider System Advantages Reduced solvents/fumes & no hot asphalt
Less use of solvent based adhesives
Techniques arent radically different
Details familiar
Either the same or very similar
Speedy application
Crew size may be reduced
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10-29-2009 In Summary Dont Forget System Limitations Increased Material Cost
Adhesive cost is built in from the factory
Positive Drainage Required
For completely self-adhered systems
Ambient Temperatures
Cold weather is bad, 45-50 degrees and rising
Reduced Coverage ?
Products with larger lap area reduce coverage
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10-29-2009 Thank You For Your Time And Consideration!