Info on single ply membrane roofing...

Originally Posted By: lkage
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…installation/inspection techniques is what I’m looking for. I understand looking for bonded seams, no tar with rubber, tears and punctures, broken joints and brittleness but could use help with the following or anything you can add:


When is a ventilation system required to prevent framing rot?
(If you're thinking "See manufacturer's installation instructions", how can a person tell the manufacturer?)

What types of mechanical fasteners are typically used to prevent liftoff?

Is using ballast typical? (If ballast is used, do you report roofing as not visible?)

Are adhesives used to attach directly to sheathing?

Does bubbled membrane usually denote moisture below?


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei

Originally Posted By: lkage
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bumped and asking for help.



“I have never met a man so ignorant that I couldn’t learn something from him.”


Galileo Galilei

Originally Posted By: ckratzer
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Larry


Are you talking about a mopped tar roof.Roll roofing w/granular slate surface.The membrane type that is sealed w/a torch.Or the white rubberized type? I’ve installed all but the latter.


Cheremie


Originally Posted By: lkage
This post was automatically imported from our archived forum.



ckratzer wrote:
Larry
Are you talking about a mopped tar roof.Roll roofing w/granular slate surface.The membrane type that is sealed w/a torch.Or the white rubberized type? I've installed all but the latter.
Cheremie


The white rubberized type, Cheremie.


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei

Originally Posted By: ckratzer
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Larry


There are a lot of brand names for that material so I’m going to refer to it as an elastomeric.


It sticks to just about anything including what is being used as membrane material ie a layer of felt for new or just the existing built up roof(BUR) on old construction.It’s sprayed,rolled or brushed on.Ballast,(gravel) is sometimes used over the top of it but then that defeats the purpose of it’s reflective qualities.I think that aspect is about preference.Some folks just don’t like the blinding whitness of it.


Uplift is not a problem if the roof is properly maintained, “seams” ,rips,holes or any place for air intrusion.Repair of such places is easy.A little fiber mesh over the trouble spot then brush over with elasto. coating .


If the membrane was fastened with any hardware hopefully you will never see it as it should be covered with the coating.If you do see the fasteners,(staples,nails) look for leaks.


Blisters do indeed indicate leaks.Water will squirt out of them if you step on them if it hasn’t already dried from the last rain.


Of all the flat roofs I’ve replaced I’ve never seen a single one that was vented but I suppose if you really wanted to a person could install soffit vents if the building had soffits.


Originally Posted By: bkelly2
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This was fun


http://www.nachi.org/roofingcoursereleased2005.htm


--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello

Originally Posted By: lkage
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bkelly2 wrote:
This was fun

http://www.nachi.org/roofingcoursereleased2005.htm



Yes, Brian, it was fun. I scored 98. ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif) It just didn't have much regarding this system of roofing.


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei

Originally Posted By: lkage
This post was automatically imported from our archived forum.



Quote:
Uplift is not a problem if the roof is properly maintained
, what are the maintenance requirements?

Thanks again, Larry.


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei

Originally Posted By: ckratzer
This post was automatically imported from our archived forum.



Larry,


What I mean by maintenance is a yearly visual inspection to check for cracks ,splits, etc. and repairing those places as described in my previous post.


Unfortunately many folks don’t think about this until the roof is actually leaking.


Yeah ,fun course.
Right after I get finished reading this book on brian surgery I'm planning on performing a surgery myself. ![icon_razz.gif](upload://rytL63tLPMQHkufGmMVcuHnsuWJ.gif) Anyone care to be my first patient
Seriously It was informative but like most things informative it's not really meant to be a how to guide but just to make you familiar with the subject.

All in good fun
Cheremie


Originally Posted By: bkelly2
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Wow Larry, good job. Maybbe this will help


http://www.ersystems.com/



“I used to be disgusted, Now I try to Be amused”-Elvis Costello

Originally Posted By: Monte Lunde
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Here is one manufacture’s site for Single-Ply (rubber) if this is the type of roof you are inspecting.


http://www.carlisle-syntec.com


--
Monte Lunde CCI, CCPM, CRI
Viking Construction Services Inc.

Originally Posted By: lkage
This post was automatically imported from our archived forum.



Cheremie,


Thanks again for the help but I'm going to pass on your surgical practice. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)


Brian and Monte,

Thanks for the sites. There was some good info in the architect's details and specifications areas.


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei

Originally Posted By: rsmith5
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There are many types of single ply roofing materials and roofing systems for installation. You need to know what the material is and how it is attached. EPDM, PVC, Modified Bitumen and others are mechanically fastened[usually in the seam], adhered [with hot asphalt or adhesives]or ballasted. Unlike built-up roofing,[more plys than a single ply system], bubbles are usually formed when being installed. There are contact adhesives that are used needing to “cure out” after the sheet meets the substrate,[not the deck sheathing], and the proper drying wasn’t achieved before mateing the materials and there is a release of gas forming the bubble.


Do you have pictures?


Originally Posted By: lkage
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Thanks Ralph. No photos but could you expand on rubber roofing?



“I have never met a man so ignorant that I couldn’t learn something from him.”


Galileo Galilei

Originally Posted By: rsmith5
This post was automatically imported from our archived forum.



Sure, first of all you will run into people that think they have a rubber roof when in reality it is modified bituman. This asphalt product is better than the rolled roofing it is designed to replace because it has been modified with rubber polymers, added to make it more flexible. A rule of thumb, if they’re using a torch to apply the roll then it ain’t rubber. Next, all single ply membranes need a suitable substrate, usually a 2"-4" sheet of fiberglass hardboard insulation but may have a high density fiberboard.


These are fastened with 3" plates[washers] and self drilling screws.


EPDM is installed in several ways, some that are no longer used. Mechanically fastened membrane [usually 7’x100’ rolls] uses flat 1" bars or 1" washers that are fastened with self drilling screws, in the seams every foot in the middle of the field and six inches at the perimeter 1-3 laps in depending on the wind uplift in the area. After fastening the bottom edge of the lap, the top section is adhered over the fasteners with a contact cement or most of the manufacturers are using a two sided tape.


Totally adhered is another attaching method using contact cement that is applied to the membrane and the substrate then rolled in. Carlisle also has a fleece backed membrane that can use asphalt to adhere it. These adhereing methods allow the installer to use 10’ or 20’x100’ rolls cutting down on the weakest point of single ply membranes-the lap splice!


The third method is ballasted. This allows the installer to use the largest sheets possible up to 50’x100’ rolls. Roof penetrations are the biggest reason to use smaller sheets. New construction is 50sq. at a crack and cut in penetratios afterwards. The insulation is loose laid, rubber rolled out, perimeter termination strips fixed, splice the laps and throw on #2 round double washed gravel and there you are, instant roof covering. When inspecting these roofs, clear the gravel from around the base of penetrations, inside and outside corners and terminations. Look for fishmouiths, cuts, flange metal edges wearing through and repairs made using rubberized roof cement as this will eat through the rubber in short order. Check terminations at walls, top of penetrations, termination bars and counterflashings. If you are dealing with a white membrane, it may be EPDM or it could be PVC. You can tell the difference easily because the PVC uses a far superior heat weld. The field seams are welded using a robot that is adjusted for speed and heat to accomodate weather conditions then welds all seams the same. The closest to factory conditions that you can get. If there is anything specific you need to know.


Ask.


Originally Posted By: lkage
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Ralph, that was very informative and helpful. Thanks much. icon_biggrin.gif


Here's a site that has pictures that can be used to help understand Ralph's info (choose the brochure file):

http://www.gaf.com/General/GafMain.asp?Silo=CONT&WS=GAF


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei