| Author |
Message |
David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt
Post Number: 1306
Registered: 03-2002
| | Posted on Wednesday, June 13, 2012 - 03:00 pm: |    |
The office has a project where there is an existing hypalon roof that is leaking (surprise surprise). The client would like to reroof, in lieu of tear off, in order to save money and not interrupt the facility.
Well the challenge is that the deck is lightweight gypsum so we can't mechanically fasten to it. So we have adhere a single ply membrane to degraded hypalon membrane.
Has anyone experience a similar situation and had luck? |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1024
Registered: 03-2003
| | Posted on Wednesday, June 13, 2012 - 03:06 pm: | |
Can you even get a manufacturer to warrant such an application?
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 273
Registered: 12-2006
| | Posted on Wednesday, June 13, 2012 - 03:08 pm: | |
I presume you're not expecting a warranty.
You could do a spray urethane foam roof but now you'll be trapping moisture in a gypsum deck with questionable adhesion to the existing membrane. I wouldn't want to be standing under there when it catches a heavy snow load!
Don't tell me, they have asbestos insulation under the roof deck and don't want to abate. I ran into that scenario at an FAA facility in Virginia 20 years ago. They finally replaced the building. |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1025
Registered: 03-2003
| | Posted on Wednesday, June 13, 2012 - 03:11 pm: | |
I should add that it may not comply with IBC Section 1510 (2009 edition) on reroofing.
New roof coverings cannot be installed "where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing."
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 274
Registered: 12-2006
| | Posted on Wednesday, June 13, 2012 - 03:41 pm: | |
I presume you're not expecting a warranty.
You could do a spray urethane foam roof but now you'll be trapping moisture in a gypsum deck with questionable adhesion to the existing membrane. I wouldn't want to be standing under there when it catches a heavy snow load!
Don't tell me, they have asbestos insulation under the roof deck and don't want to abate. I ran into that scenario at an FAA facility in Virginia 20 years ago. They finally replaced the building. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 275
Registered: 12-2006
| | Posted on Wednesday, June 13, 2012 - 03:44 pm: | |
Sorry about the double post. My computer locked up and then decided to be generous and double up on the posting.
David, has anyone spoken with a structural engineer to ensure the existing deck hasn't been compromised? |
Paul Gerber
Senior Member
Username: paulgerber
Post Number: 129
Registered: 04-2010
| | Posted on Wednesday, June 13, 2012 - 05:29 pm: | |
Another consideration should be despite the Owner's wish to save money by not doing a tear-off, if the existing roof is leaking doesn't that preclude any chance that the existing insulation below the existing membrane is not water-logged and therefore seriously diminished in its insulating ability?
Not to mention that water from leaking roof + food source (lightweight gypsum deck) = very good likelihood of mould (or mold for my American friends eh?) growth once everything is re-sealed with the new roof!!!
I'm always baffled how people who are spending as much money as they are replacing a leaking roof want to leave what's not working there to try and save a few bucks without any consideration as to how it may utimately affect the longevity and/or performance of the significant investment they are making in the new roofing system!!
Ride it like you stole it!!! |
Lynn Javoroski FCSI CCS LEEDŽ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1504
Registered: 07-2002
| | Posted on Wednesday, June 13, 2012 - 05:31 pm: | |
To say nothing about what that roofing system is protecting... |
David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt
Post Number: 1307
Registered: 03-2002
| | Posted on Wednesday, June 13, 2012 - 05:59 pm: | |
Ken,
[Don't tell me, they have asbestos insulation under the roof deck and don't want to abate.]
Close.... there is asbestos in the form board underneath the gypsum deck.
[New roof coverings cannot be installed "where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing."]
Ken, this is the argument. Some manufacturers say that hypalon is an adequate base for new roofing. So far in our research, Fibertite and Carlisle say that they will warrant their roofing over hypalon, but Sarnafil won't. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 276
Registered: 12-2006
| | Posted on Thursday, June 14, 2012 - 09:16 am: | |
Interesting that they will warrant that. Have they seen the condition?
You might want to talk with Cetco (I can't believe I'm saying this; Cetco and I haven't seen eye-to-eye for many years). They have a new membrane that may lend itself to this application called Coreflex. Let me know if you need contact info. |
Phil Kabza
Senior Member
Username: phil_kabza
Post Number: 508
Registered: 12-2002
| | Posted on Thursday, June 14, 2012 - 07:34 pm: | |
The new membrane manufacturer may warrant the performance of their membrane in such a circumstance, but if you get out your magnifying glass and UV light you will see that their standard warranty takes no responsibility for the issues related to the guano you are attaching to or the resultant failure of the fastening. You've captured a vapor barrier above a hygroscopic deck material poured over a form material made of hazardous material.
I think your firm should look for spec projects in Kazakhstan instead. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 282
Registered: 12-2006
| | Posted on Friday, June 15, 2012 - 12:56 pm: | |
Oh come on Phil. Can't they just spray an encapsulant to the underside after they trap everthing from above? |
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