is this a properly done rubber roof?
Im building (remodeling) an old house here in chicago and my conractor installed a new rubber roof. the sloping did not look right in the first place and when I checked one day after it rained, it looks like the roof is just collecting sitting water (look at the pics below).
my questions here are:
(1) is this a properly installed roof? (it does not look like it to me).
(2) how should this be fixed? will this have to be completelly removed and redone?
thank you, ssl
Its not a rubber roof first of all. its a modified bitumen roof, thats basicly glorified rolled roofing.
thank you for that bit of info... can you also tell me what you think of the work in the above pics?
thank you, ssl
Agreed, and also a poor job.
Hard to tell from the photo's, but there is wayyyyyyy to much water laying in one spot.
Where to start???
It is a rather poor job, Let's tackle the issues one at a time.
#1 The lap seams are going in the wrong direction. Lap seams should be along the long length of the roof section. with the lap seams overlapped with the flow of water not gaianst or with the flow.
#2 The wall flashings are way too short. The flashings should go up the wall a minimum of 18". I would prefer to see them all the way up and over the top of the wall. Additionally the lap seams of the flashings are not sealed AT ALL! There should be a cant strip along the bottom of the vertical to horizontal wall transition to break the transition of the Mod Bit membrane.
#3 Where are the drains? There should be either drains in the field area or at the very least scuppers along the long wall to drain the water.
Modified Bitumen is more than just glorified rolled roofing. It's a matter of quality of the material. Derbigum is not glorified rolled roofing.
If you paid $10.00 a roll (square) for it at your local home center yep, it's junk.
I service Mod bits all the time, I have one customer with a 20 yr old Mod bit roof that we installed, that for the first time was coated this year.
My recommendation, Contact a commercial roofer. In my opinion the roof has to come off and replaced. Drains and/or scuppers have to be installed.
Is there any insulation? Is this over an occupied space?
Probably not what you wanted to hear but, this is not really a DIY project given the layout and lack of drainage.
this actually what I need to hear and tell my contractor. Im not happy here. this is pretty large house (5000+ sqf) and not having a good roof would keep me up at night.... :furious:
the drains are yet to be installed, so that I hope will not be an issue. as for the material used, I have no idea what it is, or how much it was. I will take a look and report.
at this point, I really just want a pro roofer to do this job, not someone that "has done a roof once before."
any other suggestions as to what to do here? will this really have to all come off and redone? including the plywood to make the roof slope properly?
thank you, ssl
ps. below is what the roof specs were as per my plans from the architect - so its not like the "direction" was absent:
Roof Membrane Notes
1. ‘Flat’ roof membrane is to be single ply modified
bitumen, atactic polypropylene (AAP) type SP-4 as
manufactured by U.S. Intec, Inc. or approved equal.
2. Surfacing is to consist of an aluminum coating
compatible with the membrane to provide resistance to UV
3. Sheet metal flashing, counter flashing and caps, shall be
22 gauge minimum galvanized steel.
4. Provide curbs and flashing systems as required for vent
pipes, skylights, chimneys and other items indicated.
5. Provide flashing as needed to make the roof work water
tight. Roof shall be water tight at completion of the
6. Gutters and rain drainage accessories shall be heavy ga.
copper, unless noted otherwise.
7. The roof system and related flashings shall be
warranted against defects in material and
workmanship for a period of 10 years following
Owner acceptance. Warranty coverage shall also
include the complete repair and replacement of other
building components which are damaged as a result of
a roof system failure.
8. The completed roof shall be free from all conditions
which led to ponding of water. Ponding is hereby
defined as any body of standing water which does not
evaporate within 24 hours of being deposited on the
9. Provide roof membrane protection boards over all
surfaces within 3 ft. of rooftop HVAC equipment.
10. Terminate membrane a minimum of 8” above roof.
11. All lumber used for nailers, cants and curbing shall be
pressure treated wood.
12. Provide 36” wide W.R. Grace ‘Ice and Water Shield’ self
adhesive membrane at all valleys and perimeter eave
locations. Install per mfrs. specs.
13. Provide roof ventilation as required by code to provide a
min. of 1 s.f. free vent area per 200 s.f. of roof area.
I wish my customers would provide half that much info...
So here it goes.
Hire a "Commercial" roofing company. I say that beause this job is not one for a residential steep company that does low slope once in while. I'm with a large commerical company with a residential division.
We work back and forth for each other. They have a flat portion that needs to be done, We do it, we have a shingle portion of a job, they do it.
I would tear off the existing membrane and any insulation down to the deck. The slope of the existing deck really is not the issue. Proper membrane installation is. The plywood should be able to stay if it's not damaged from leaks.
The roofing notes do not mention thermal insualtion on the deck.
International Building Code which all roofing contractors must abide by states that an occupied heated space must have a minimum R-20 thermal insulation on the deck. Typically our spec is 2.5" of Poly-Isocyanurate insualtion and a layer of 3/4" perlite insulation R=20.58 LTTR. All joints staggered.
Then a base sheet. It all can be mechanically attached with screws and plates or it can be adhered with cold applied adhesive.
Your cap sheet is then either torch applied or adhered with adhesive.
I'm not a big fan of Aluminum coating Mod bit. Have your contractor provide you options of surfacing. Performance Roofing Systems "Derbicolor GP" is a great product. (www.derbigum.com)
As you can tell I'm rather partial to mod bit as opposed to other materials such as EPDM (rubber) PVC, TPO
Don't get me wrong I'm not bashing the other products, they are all fine, As a contractor we all have our favorite materials.
A good roofing contractor will offer a couple of different options.. IF you ask them to. Otherwiase you'll get their favorite only. We supply alternates as a normal course of our business.
9 times out of 10 it's not the product it's the installation.
It won't be "cheap" but you only pay for quality once.
You may need taperd insulation to solve the ponding water issue. or mabee interior roof drains
Wewll, roofer Jim doesnt know modified bitumen, thats apparent with his ignorant response about the glorified roll roofing comment.
Also, I thought the IBC states that r 20 is needed, but not necessarily above the deck if a cold assembly is used.
Most of the flashings are NOT even present.
How long is it before water evacuation? GAF allows 72 hours.
Did you go with the lowest priced contractor? IF you did, would you expect anything else?
Aluminum roof coating is a waste of money.
GAF does not allow this product to be installed other than torched.
GAF no longer sells U.S. Intec in Chicago.
Does his bid include tapered? Did the others? Is this ambiguous in the contract? Did you go with the contractor that didnt include the tapered spec even though you knew it would be necessary?
Is this a new roof deck? If so, why was it not built with sufficeint pitch to evacuate the water?
All this in addition to my responses at that other website.
Im certainly not trying to "save" any money here. I hired architect, structural eng, mechanical eng and so on.... this is not a cheap project by any means.... the roof and the structure is what Im worried about the most (hence the other trades hired)...
I think one thing we need to know is, Are all the sides surrounded by parapet walls?
Is there an open end for the water to drain to?
ssl, I'm going to say something here that may ruffle more than a few feathers...
GC's in some cases are NOT your best friend.
Like most other GC's and his subs, he is trying to bring his project in under budget.
While other trades may complain that they are the target of money contraints it truley is the roofer that more times than not is the primary target.
I think that's what happened here. Your GC is trying to "bring the job in" That means saving a few bucks here and there.
You really can't tell the drywallers to use an inferior product, Final product can be seen.
HVAC guy's? Nope, can't have the tenant/owner too cold or too hot.
Carpenters? Nope, can't have it falling down.
It comes down to the roof. Out of sight out of mind. any roof material will do for a while. A WHILE.
You're on the right track, INSIST on the correct roof system, correctly designed and installed by the right contractor.
What is that system? I don't know for you. Certainly not the one you are getting from the GC's good buddy the "roofer".
This your building. you should get what you want.
I agree with ths Talos4 guy...look to the GC, who will most likely try to push it off on the roofer.
BraiSP4 is a fine product. I would not rate Ruberoid as the same, but that is one man's opinion. SP4 is no Derbigum, but it is better than Ruberoid.
Well Aaron im not getting into your roofing ego pissing contest that you guys somtimes enjoy. but as a journymen Roofer & Sheet Metal man for over "20years" Im far from ignorant . I have installed quite a bit of modified, the stuff is not done in New England hardly ever anymore for damn good reason "its crap" yes there are some that are better than others I may install one every two years. we maily use it as a repair material.
the single ply's are a far better roof, Its just you torch & paint guys would have to learn some skills & finesse .
Have a great Roofing Day
Well, I really hoped we could have a conversation trying to help someone without getting "snarky"
"Roofing Ego" has nothing to do with what Aaron and I are saying.
The company I work for has been in business for 129 years. I've been here for 15 of those years.
The founding family and it's current members built this company on Built up roofing and Mod Bit.
We have long history of installing mod bit. and YES we use almost exclusively Perfromance Roofing Systems products. Why? Because we feel they have the best products. We have many mod bit roofs in excess of 20 years of age that are performing better than spec.
I only recommend or propose products that we will stand behind and those that the manufaturer will stand behind.
We are not fans of "plastic" roofs. We do plenty of EPDM (rubber).
TPO, PVC, and all the other acronyms have not established the service record of Built up, Mod Bit and EPDM.
As far as being a Torch and Paint guy. We don't recommend coatings. Covering a problem is still a problem.
Torching is an art. Many roofing companies are NOT being allowed by their insurance companies to install torch applied systems. Our EMR and OIR allows for that. We are approved to torch apply roof membranes. And have not in our history burned a building down.
(obligatory "snarky" remark here)
In addition to being "Torch and Paint Guys" don't forget... We are first and foremost the "Best mop and lugger guys" around.:thumbup:
Pissing contest? There is no pissing contest here. I just find it out of line that you will bash a quality system simply because you dont do it.
We have mod bit roofs on for appraoching 20 years with nery a failure. Please explain what is bad about modified bitumen and also what is so superior about the single plies. I have seamless single ply systems that are far superior to PVC, EPDM, TPO, or Hypalon.
|All times are GMT -5. The time now is 05:15 PM.|
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.