| Author |
Message |
Addcap (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, February 21, 2013 - 07:31 pm: |    |
Ok, I am not a contractor. I am a homeowner in a high rise building in the northeast. I am looking to redo 2 roofs that will become outdoor spaces with a pedestal and paver system. That will need to withstand a decent amount of weight.
The roof currently has a Siplast Modified Roof that was installed in 2004. There is no pedestal or paver system currently, just the roof. It has few leaks. The roofs are on the 18th and 19th floors, with slight variation between the 2 roofs.
The 2 slight differences between the 2 roofs:
1. On the 18th floor the siplast modified is set over the existing quarry tile pavers that were on the original terrace. Hardboard was put over the pavers that already had a pitch, so there is not crushable insulation under this surface
2. The roof on the 19th floor has insulation over concrete to make the taper.
I have had proposals for a a Siplast Parapro roof to be put on top of the existing siplast modified roofs. The other proposal is for an EPDM roof to be applied on top of the existing siplast modified roof.
Can anyone suggest which is the better proposal for this type of application? Orif there is another roofing system out there that is superior to either of these? I know very little about any of this. Please help! |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 437
Registered: 12-2006
| | Posted on Thursday, February 21, 2013 - 09:52 pm: | |
You certainly have your work cut out for you.
First, if the roofs were installed in 2004 they should still be under warranty unless you've done something to void it. Find out. Get your Siplast rep out there.
Second, pay a Structural Engineer to determine whether your building system can withstand the loads imposed by a paver system.
Third, if you are changing the use of the roof areas so that you will have people using the roof area you may need to consult with an architect or Code specialist to make sure you are having the structural engineer check the right loading requirements.
Fourth, please do not ask roofers or roofing reps to suggest solutions. They will screw you over and you will have no recourse and no one to blame but yourself. I'm not being mean here; this is a sad reality.
I am presuming that you own a unit in a condo and somehow have volunteered to investigate options. Please remember that no good deed goes unpunished. Anything that happens will be considered as your fault by your neighbors.
If you'd like, please give Colin your contact info and ask him to forward it to me. I am from the 'northeast' having lived in DC, Baltimore, and Boston and used to be a roofing and waterproofing consultant. There are a lot of good people out there (and a few I'd avoid). Please consider spending a few hundred bucks and hire one of them for an initial consultation. They can educate you more in an hour than I can in this forum.
There may be numerous good options for you but there is some upfront legwork that you need to do first. Going into a significant risk situation like this with little to no knoweldge can lead to a less than optimal result.
As an aside, please don't go with the EPDM. |
spiper (Unregistered Guest)
Unregistered guest
| | Posted on Friday, February 22, 2013 - 09:55 am: | |
I agree with Ken that there are too many variables on something like this to trust it to a forum.
I would also try and determine the condition of the existing roofs and the materials under them. I believe it would be advisable to pay someone to do a core of the existing roofs to determine the existing conditions. You are hoping to install the new roof over the existing one which can work very well but you have to ensure that what you are going over is a suitable substrate. If you build on crap you get crap.
As an aside to Ken's aside, our office uses EPDM regularly (Midwest region) and we have great sucess with it. That however does not make it best for your situation or your region. I just mention it to let you know that there are many options and many opinions out there. |
Addcap (Unregistered Guest)
Unregistered guest
| | Posted on Friday, February 22, 2013 - 12:29 pm: | |
Hiring a consultant would be fine. In fact, sounds like a great idea.
I passed my contact info along to Colin, a recommendation would be great! |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 438
Registered: 12-2006
| | Posted on Friday, February 22, 2013 - 02:48 pm: | |
Michael,
I'll send you a short list of some consultants I've use as soon as I get a moment. You can always check with Roof Consultants Institute - http://www.rci-online.org/.
Colin did send me your info. I have sent you an email with my contact info.
Let's plan on talking soon. |
Ron Beard CCS
Senior Member
Username: rm_beard_ccs
Post Number: 401
Registered: 10-2002
| | Posted on Friday, February 22, 2013 - 05:44 pm: | |
With due respect to my ol’ buddy Ken, IMHO I have not had significant issues with EPDM membranes having specified hundreds in the same areas of the country, and beyond, that Ken lists. Ken please elaborate. I recognize that getting a large roll of heavy sheet goods up 19 stories is problematic but what are your specific objections to the system itself, if any?
There are many excellent roof membranes but each has it own individual pro’s and con’s. Each project should have its roof system selected based on its own particular design considerations: number of penetrations, substrates, budget, expected life cycle, available qualified installers and manufacturer’s field representatives, type of structure (ie, high-rise vs low-rise), etc.
The best advice, as stated above, is to get a qualified ‘roof consultant’ and structural engineer onboard to investigate the specific existing conditions and project details. Weight will be an issue. You have already stated that there is existing quarry tile within the existing roof system plus one or more roof systems.
Do not assume that there is no crushable insulation in-place. As a general rule, most insulations are crushable especially the foam and EPS types. Extruded foams in roofing applications usually are 40-psi; expanded are usually less. Under pedestal systems, 60-psi insulation should be used; and, 100-psi insulation should be used under pedestal systems supporting heavy tree and other vegetation containers.
Also, I do not agree that “roofers and roofing reps” will screw you over. Sure some less desirable ones are out there, but use their services wisely. Their job is to sell their employers products. Ask them for their recommendations as to the best products they can offer based on the roof design criteria you or your roofing consultant develop. Have the roofer/reps offer apples-to-apples considerations; if not, you will get a fruit salad of solutions.
"Fast is good, but accurate is better."
.............Wyatt Earp |
Addcap (Unregistered Guest)
Unregistered guest
| | Posted on Saturday, February 23, 2013 - 10:28 am: | |
The information regarding no crushable insulation came directly from the installer of the current Siplast mod bit roof. That fact only pertains to the 18th floor. They confirmed the other roof has crushable insulation. The original roofing installer indicted the roof on 19th w/ crushable insulation could bear no more than 23psi. Which is well below what we will be looking to do. We would probably be aiming for the 100 psi for heavy pots with trees.
Also, as far as getting material up to the 19th floor, we actually purchased a swing hoist (been a life saver) for the project that is temporarily setup on the roof of the 20th floor (this roof is not being considered for a pedestal system, but is the very top of the building with great access to the alley below). So while moving materials is obviously still a tricky task, it's not as bad as one might think for a fit out of a space within an occupied residential condo high rise. Once it is finished it will be a different story..
As far a penetrations, there are next to none on the roofs which will bear the pedestals and pavers. The 20th floor roof has numerous, but that will not have a pedestal system, so it's a bit of a different animal on that one. |
Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre
Post Number: 1305
Registered: 07-2002
| | Posted on Monday, February 25, 2013 - 04:29 pm: | |
some points:
I, too, have used a lot of EPDM over the years, as well as TPO roofing -- which has a slightly larger temperature range for installation. I've had projects where the cost difference between the EPDM and TPO varied accoording to the cost of oil, and had projects where the bids went back and forth three times until we finally installed TPO.
Siplast seems to be the most concerned about "crushable " insulation -- they comment on it more than any other roofing membrane I've worked with.
I agree with the assement of roofers and/or roofing consultants -- I've had good and bad luck with both. What I think is the most important is the roofing manufacturer will back up the installer, and get the best installation, inspection and warrranty for the project. |
Dale Hurttgam, NCARB, AIA,LEED AP, CSI
Senior Member
Username: dwhurttgam
Post Number: 108
Registered: 10-2005
| | Posted on Tuesday, February 26, 2013 - 03:57 pm: | |
Getting back to some of Ken's first comments. having the roof evaluated for stuctural capacity is of the utmost importance. Most roofs are not designed with the extra capacity to support a paver system and potentially one with intensive roof garden features such as heavy pots and large trees. Additionally - what type of parapet does the building have - is it of sufficient height to also serve as a guard rail. Need at least 42" beyond the height of the pedestal system.
These items should be determined before even needing to consider and debate about the best roof system to install. |
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