Originally Posted by Talos4
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.
thank you Talos for the info.
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....
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.