Comments on: IRMA (Inverted Roof Membrane Assembly)

By: Joe

Joe — Thu, 15 Dec 2011 20:39:15 +0000

Wow, I guess including my contact information and all that serves me right to recieve such a harsh comment. I will definately read through it again to ensure that you are correct in your take. I am not sure however that you are, and based upon much of the response that I have recieved, you may not be. As for your professional association, I don’t need to know and don’t care, because anybody that would throw it out there such as you did and then hide behind that cannot be very credible. Liability? Are you serious?

By: Joe

Joe — Thu, 15 Dec 2011 20:27:31 +0000

Almost all are fully adhered. To break it down, Fluid-applied waterproofing such as Hot Rubberized asphalt by nature will be fully adhered. A peel and stick system (Grace Bituthene membrane) would be fully adhered. A PVC single ply membrane would typically be fully adhered as well. The main reason is to localize leaks! You do not want water to run UNDER the membrane which makes a leak very hard to detect. So Fully Adhering is really the best method of attachment for this as well as other roofing assemblies. Regards; Joe

By: Joe

Joe — Thu, 15 Dec 2011 20:22:56 +0000

Absolutely. Send a link or send our web address as well. Please keep in touch and let me know if you were able to benefit from the information.
Regards; Joe

By: Joe

Joe — Thu, 15 Dec 2011 20:15:04 +0000

I apologize, you are right of course and I am going to follow up with some photos soon. Stay tuned. I hope that you will enjoy them.
Regards; Joe

By: Joe

Joe — Thu, 15 Dec 2011 20:09:37 +0000

Gary;
Just getting to your comment. I have to say I am not sure I follow any of it? The facts about the IRMA systems are clear. Can there be debate over which assembly to use over another, yes? But that is not what the blog was about. As for vapor drive or net R-value? I am not sure I follow you on this? Maybe you can go to the RCI (Roof Consultants Institute) website and review some of the Technical information they provide. I would be happy to answer a specific question if you have one. Regards; Joe

By: Joe

Joe — Thu, 15 Dec 2011 20:04:51 +0000

Sorry for the long delay. We moved our offices this fall and I didn’t realize what that was going to entail. In response to your question, the answer is yes. Your surfacing will be the largest consideration after the membrane of course. Will you pour concrete, install interlocking pavers, etc.? Anytime you are waterproofing a balcony that is over occupied space and there will be foot traffic, we recommend a paver system that can be removed. This eliminates the demolition of topping slab if repairs are required. Removing pavers can be performed to inspect the membrane, or repair if necessary afterwhich you can put the paver back in place. A good solid membrane is key, but overall choosing this type of assembly is a solid long term approach. Regards; Joe

By: Joe

Joe — Thu, 15 Dec 2011 19:56:56 +0000

Jerry;
Hope everything is going well on the project. With your assembly, the water will travel to the drains in both locations. The grooved drainage allows water to flow under the insulation. This works best if the deck is sloped. We typically will tape the insulation and use a drainage board on top of the insulation to capture as much water and get it to the drain prior to getting down to the membrane. This way if slope to drain is minimal we can use slope in the insulation to our benefit. It is also less costly to slope the insulation then a structural deck. Send me a photo of the completed assembly, I would love to see it. Regards; Joe

By: Joe

Joe — Thu, 15 Dec 2011 19:52:42 +0000

Randy;
Good question! In almost all IRMA systems, the membrane is adhered to the deck. Don’t be confused by loose laid ballasted systems such as EPDM or PVC’s where the membrane is applied OVER the insulation then the ballast is used to hold the assembly down. A true IRMA system will always have the membrane applied to the substrate first. The paver, ballast or combination of surfacing will need to be sufficient weight to hold the insulation in place based upon the Wind Uplift Requirements for the project location. (Refer to FM Global for Wind Uplift). My recommendation? Always fully adhere the membrane. Thanks; Joe

By: Joe

Joe — Thu, 15 Dec 2011 19:48:53 +0000

John;
Sorry I have not replied sooner. We moved our offices and I have been busy with the new set up, etc. To get to your question, here is what I believe:
First of all you have to identify the overall surfacing. Is it pavers, ballast, a combination or do you have a concrete overlay? with regards to the type of insulation, you do not want damage any insulation so care needs to be taken when removing it. I recommend that in order to visually inspect the membrane, you do it at key points in the assembly. Drain locations (where much of your water will be noted); Flashing areas where transitions occur in the membrane; AND some locations where you have your heaviest foot traffic. This way you will be checking not only the membrane, but the insulation condition as well. At the flashing transitions you want to review the stress imposed on the membrane. I do not recommend test cuts within the first 10 years unless there are leaks occurring. A test cut must be immediately repaired with like materials so proper planning is required. D 7 performs roof inspection annually for many clients and travels across the country to perform this work on a regular basis. Give us a call sometime to discuss more of what you can do regarding your maintenance program or other roofing needs. Thanks for the post; Joe

By: Joe

Joe — Thu, 15 Dec 2011 19:38:03 +0000

I will check it out. Haven’t heard of this issue, but thank you for the heads up.
Regards; Joe