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This Video explains the method of installing a Modified Bitumen Torch Down Rubber roof over Tar and Gravel

Video Transcription - Commercial Roof Installation: 2 Ply Rubber over Hot-Tar-and-Gravel

Hi, My Name is Erik, with Commercial Roof USA

commercial roof installation

I’m here on a commercial roof that was a gravel, a pitch and gravel roof here. And they called us in to re-roof it and we’re we decided to go over because rather than strip all the gravel off and all the old tar, we saved them a lot of cost by going directly over and I started about an hour ago and this is our fiberglass liner that I am laying down right now. Um this is the first step.

Self Adhering Base

Next comes the self adhering base then our final layer of modified bitumen torch down. So, as you can see I’m going over gravel right now. I’ll finish it up and I’ll show you the progress as the roof gets completed.

Cost-Effective Roofing System

This is the most cost effective roof put on uh rather than stripping it down to the wood and removing all the gravel the debris all that labor and also the time that it takes. This is one of the most cost effective roofs that you can do. We go directly over and um it’s just as good as if we stripped it all the way down.

Same Warranty

You get the same uh, you know warranty, um but this is one of the most cost effective ways to do it both with time labor and debris removal. This is why we advocate this because this is an excellent roof it’ll last you easily twenty thirty years and it is half the cost of the other roofs out there.

Process of Installing a 2 Ply Rubber Roof

Alright, I’ve already laid down my uh fiberglass liner and uh I’ve anchored it down. This gives the roof the strength and stiffness it needs and uh we have a two ply system we do. This is the first of those of the two ply. It’s a self-adhering base. You can see right here it’s already starting to it’s already starting to adhere and it’s gonna stay that way um and then after that we are gonna torch our modified membrane to this fusing it together.

The Best Rubber Roofs

This is why it’s one of the best roofs out there. Uh, you get a two layer membrane as well as the protection, the fiberglass liner. You can’t beat it. Uh, so we went with white on this roof to reflect the sun and to keep it cool and um here’s the granular that you see on top and these are made of ceramic these are ceramic granular and uh they protect against the UV rays which usually break up the roof.

Ending Prematurely

This makes it end prematurely and then uh we’re fusing this layer directly to our other two layers and I’ll show in a second just how thick it is but this is why this is a good system it makes it one unified membrane all across.

Thickness of the Layers

So uh, let me show you how thick it is here. Alright, you see? That’s how thick it is. You could see, I might be able to peel this open. There’s our first layer, the fiberglass liner, that gives that strength that’s anchored down to the to the roof with screws. And then I can’t separate the other two cause they’re fused together, but uh you can see how thick that is that and uh also the strength that fiberglass liner gives it; it’s not as pliable anymore.

What You See is What You Get

You see that? That’s the roof that you’re getting. This is what makes it one of the best systems out there especially over gravel or anything like that. Okay uh, we are ready to do the curb flashing around the chimneys and skylights and now we’re just rolling out the big the big rolls over here to finish up the roof. Look how they flow together.

Commercial Roof Installation: 2 Ply Rubber over Hot-Tar-and-Gravel

Our commercial roof installation of a 2 ply rubber roof, over hot-tar-and-gravel, has been tested and proven to withstand extreme weather, foot traffic and harmful UV rays, for many decades. The system consists of a reinforced fiberglass asphalt base sheet, placed directly over the gravel, and fastened down with plates and anchors, to the roof. Over this fiberglass base sheet, we install a self-adhering membrane; this combination becomes our first ply. Lastly, we fuse a cap sheet of Modified Bitumen Torch Down Rubber to it, which has embedded ceramic granules on the surface, for protection against harmful UV rays.

Commercial Roof Installation: New Modified Bitumen Rubber (MB) over Old MB Rubber 

When a roof has an existing MB membrane, there is no need to remove it, rather, fusing an additional MB Torch Down membrane to it, creates a 2-ply rubber membrane.  The installation of this type of roofing system will reduce labor costs and provide a life expectancy of 40 years, and beyond.

Although a 2 Ply MB roof is the best roofing system, it can be compromised if roofing technicians do not have the experience and skills to perform the necessary flash detailing around mechanical units, drains, and vents. Most importantly, however, the entire surface of the membrane must be skillfully heat fused with a torch.

This video explains the three roofing systems available: TPO, EPDM and Modified Bitumen Torch Down

Video Transcription - Flat Roof Installation Systems Compared

Explaining the 3 Roofing Systems 

I want to explain to you about the three different systems that are available on the market for redoing a roof over a commercial roof. First of all you get the TPO type of membrane which is a white membrane and it a vinyl or PVC type of material and it’s called a single ply membrane. Then you can get the EPDM. Let me show you the EPDM here at the bottom. Andre want to this is the EPDM membrane and it’s also a single ply membrane like the inner tube of a car.

Comparing Two Rubber Roofs

You can see it stretches like that and then you get another single ply membrane which is the modified bitumen membrane like this one. This is a modified asphalt and it becomes rubber. The three systems are all called single ply membranes and they all have a different technique of installation.

TPO is Heat-Welded

TPO needs to be heat welded on the seams and you need to have a surface that is fairly flat and smooth before you install it and the same with the EPDM. EPDM is very thin and hold that side Andre and also it’s a single ply membrane and it has to be installed over very smooth surface and it’s a glue down process.

That means contact cement. You add contact cement onto this side and the other side and you glue them together and that way that’s how the seams are done. Uh this is how easy you can penetrate through uh EPDM. I can hold it there. You see the knife? It goes just like that. Easy.

Modified Bitumen is a Thicker Membrane

Modified Bitumen is a thicker membrane and it can be installed over almost any surface, a rough surface. It’s not necessary has to be smooth. What makes this such a better system, or a better membrane is you can hardly get through the membrane. That’s how hard it is to get through this membrane. I can barely get my knife through there.

Install a Modified Bitumen Membrane

I have to put a lot of pressure in it. Now the way you, what we do is we have gone a step further. We install the modified bitumen membrane over another membrane on top of a base paper. Now, I’m going to explain this to you, but we call it a two ply system. A two ply system is by far the best roofing system out there.

Life Span of a Roof

There’s nothing that can come close to it. All these single ply membranes even the modified by itself, they give a guarantee of twelve to fifteen years. That’s what the life expectancy is. That’s not enough for a commercial roof. If you have a commercial building, you don’t want to replace the roof every twelve fifteen years. The system what we have is a two-ply system. Let me I’m gonna just explain to you. Here we’re busy doing a roof over the stone here and you can see the stone. We smooth out the stone like this then we add a fiber liner.

A Fiberglass Liner for a Rubber Roof

This is a fiberglass liner that can go over the stone. You can see the stones doesn’t come through. It doesn’t penetrate through. That is to give it the stiffness to the roof and make it like a rigid roof. After we install the fiber uh, uh liner, then we install a single ply self-adhering membrane. You can see this is sticking to this base.

Installing a Base

It’s starting to stick there. You see there? This is sticking to the base and after we install that fiber liner and then this base, we then torch down our membrane, the final layer on top of this self-adhering base. By the time you’re done, it becomes a very thick roof and this system can be installed over any type of roof any surface without having to strip the cost of stripping an entire roof and it will last you guaranteed thirty to forty years easily no questions about it.

The Thickness of a Roof

This is what it looks like. Look how thick it is. I don’t know if you can see it. Can you zoom in onto this Erik? Let me get the EPDM. Can you see the two difference there? This is the difference in thickness. Can you see it? And this two ply system, you can do modified a single ply system we don’t recommend that.

It’s still a single ply roof, but once you go to a two ply system with a modified, you cannot do it with EPDM you cannot do it with TPO, that white uh, uh, vinyl type of roof, but you can do it with a modified, you can do two ply system with the modified and you’ll have the best system out there. Nothing can beat it. So, I explained to you about the two ply system. So we went over an original built up roof.

Old Hot Tar Built Up Roof

This is the old hot tar built up roof hot tar and paper and it started cracking and the owners of this building wanted to reroof and so we went over the hot tar. This is a two ply system. There’s the first membrane and there’s the second membrane. I cannot get it apart. It’s stuck to it.

The first membrane is sticks to the hot tar and the next one we torch to this it sticks to this. It’s indestructible! Then you can look, pan over this this is how it looks like we went over here. This area has stone underneath here. We went over the stone area and you can see we still in the process. We almost done.

Torch Down Membrane

This is the membrane the torch down, and this is the second base here; the self adhering base and then we have the liner the fiberglass liner and this is the stone here. We almost complete with this roof and this roof will outlast any other system out there. I don’t care which one you bring to me.

TPO Not Lasting Long

The TPO, the EPDM, they cannot last as long as this roof would last. This will last thirty to and I’m sure it’s gonna go to fifty years. This is how good this type of roof is and leaks? No way! It can never leak even if they don’t the whole thing about single ply membranes is technique.

Installing TPO

TPO has a certain technique the heat weld and so has EPDM has certain techniques, but the glue on EPDMs do fail after three or five years or ten years. That contact cement, it fails in the heat. Both of the TPO and EPDM are not UV protected. They don’t have the protection. With the modified it has the granular surface that has UV protection, it’s double the thickness then we added another layer it makes it three or four times thicker than any other single ply membrane. No UV can destroy it, and that’s the best system out there. Bar none!

Modified Bitumen: Four Reasons to Install an MB 2 Ply Roofing System 

  • Embedded ceramic granules protect the membrane against harmful UV rays.
  • The membrane becomes five times thicker than a single-ply membrane (EPDM and TPO).
  • Seams are fused together with a propane torch creating a monolithic membrane.
  • It will withstand more frequent foot traffic and snow shoveling, than EPDM or TPO systems.

Commercial Roof Installation: A 2 Ply MB Roofing over any other Roof, is Cost-Effective

When an existing commercial roof needs to be replaced, the best system to install is a 2 Ply Modified Bitumen Torch Down Membrane. Not only can this 2 ply system be installed over a Hot-Tar-and-Gravel Roof system, it can also be installed over an existing EPDM Rubber Membrane, and a TPO Membrane,  making it cost effective.

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  1. Adam Lawrence

    Very expressive and easy understandable blog you have shared. I think you are one of them who are very clear about how to express the ideas and views. Thank you for sharing this kind of blog.

  2. Jacob Gill

    Whether you are a building owner, engineer or contractor, choosing the right commercial roofing system for your project is crucial. Excellent post. I want to thank you for this informative read.

  3. Debbie

    Love your video and your 40 year old warranty. Gee, you all could make a mint if your company came to NM. We have tons of flat top roofs- pueblo style. Any plans on coming to New Mexico? We need your roofing system here as we are usually stuck with TPO that leaks, foam that is a disaster, or tar and gravel which cracks and leaks.

    • Naas Ferreira

      Thanks Debbie
      You are not the only one stuck. It’s all to do with marketing campaigns. These big companies know how to make their products sound great but never reveal the negatives about it. Even government entities like towns and cities have fallen for the idea of Torch Down Roofing is not good due to the chances of building down a building or the environmentalists have claimed that burning the propane torch causes harmful gasses.
      In the end, the chemicals that are used to produce the TPO and synthetic EPDM rubber is far worse than making Modified Bitumen Rubber. TPO is plastic and will pollute the environment for many many decades to come.

      I need a wife, so if you have someone interested in me down there, I might decide to live there and start a roofing company. lol

  4. John Farrari

    Hi This was an interesting video on installing a roof over gravel.


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