Construction worker installing roofing with nail gun on a wooden structure against a blue sky.

Commercial Roofing Services for Mill Buildings (Podcasts)

In this episode, John Maher speaks with Brett Rogenski, General Manager of Master Roofers, about the unique challenges of roofing historic mill buildings across New England. Rogenski explains how these massive, aging structures often require specialized assessments due to multiple roofing layers, parapets, and modern rooftop mechanical systems. He details the materials commonly used—such as EPDM and TPO—and how new technologies like heat-welded seams and tapered insulation improve durability and energy efficiency. The conversation covers maintaining historical aesthetics, budgeting through regular inspections, and managing roof-mounted solar arrays. Brett emphasizes proactive planning to avoid costly surprises and ensure long-term roofing success for mill building owners.

John Maher: Hi, I am John Maher and I'm here today with Brett Rogenski, general manager of Master Roofers, the most trusted roofing company in New Hampshire for over 80 years. Today we're talking about commercial roofing services for mill buildings. Welcome Brett.

Brett Rogenski: Thank you for having me today, John.

Commercial Roofing for Mill Buildings

Maher: Sure. Brett, Master Roofers is up there in Manchester, New Hampshire, and I know that you have a lot of old historic mill buildings in the area, both in Manchester and in Concord and then down in Massachusetts in places like Lowell and Lawrence. So lots of mill buildings in this area. What are some of the unique structural characteristics that mill buildings have that affect roofing decisions and installations?

Rogenski: Sure, that's a great question, John. Yeah, you're right, we do have a lot of those structures here in New England and Master Roofers we serve in New Hampshire and North Shore Massachusetts and Southern Maine. And those are all areas that are dense with those sort of buildings. And the great news is in the last couple of decades, it's become very popular as well to repurpose those buildings, so reinvigorate them as opposed to just letting them sit vacant or worse yet fall into disrepair.

So, it's unique. A lot of these are old buildings, they're turn of the century buildings that used to be shoe factories and felt mills and woolen mills, and I could go on forever, but those are some things that we see pretty commonly. So, the typical is very often the brick, very often they have wide span flat roofs and they also very often have parapets around them, little wall around the outside of the top and that sort of thing, which those things first you go, okay, so what?

But those are some of the structural characteristics that then determine what we can do for roofing on those, it's obviously almost always a re-roof, unless they ... well it's always a re-roof, the building was existing. No one's putting up new mill buildings like that. So, the characteristics are typically that they've probably been re-roofed over many times, you're looking at a hundred-year-old commercial building, they probably have multiple mediums as well.

So, that thing originally was probably tar and gravel, which is exactly what it sounds like it was, tar and gravel. They put down boards, usually something that was kind of like felt, let's call it that, and then tar and gravel.

And that was very common for a long time. It was better than the other option, which was not much. So, tar and gravel. And then probably years later, after maybe a couple layers of tar and gravel, it may have gotten an EPDM or rubber roof of some generation of rubber roofing. And so, what that we do is we make sure that when we start engaging these buildings, we do a core cut to see what is the decking of this building, how is this thing made?

It's usually boards as opposed to what we would use now, which is more of a, I don't know, consider it a plywood type product, and how many layers of stuff do we have, because there's also load considerations to have. We can't just keep piling stuff on the roof because eventually then the roof will become the floor the hard way.

And so, we do what's called a core cut where we basically take sample cuts in there and then we go back and seal them, obviously, to see, hey, what is this thing made of? How many layers of roofing do we have? What do we have for what is our substrate here? And then that determines, number one, is this going to be a ripoff? Are we going to have to strip off the old roofing or is this something that we can simply go over?

Depends how many layers there are, and depends on weight. It also depends on what the customer's budget is and et cetera. But there are code limits on how many times we can re-roof and that's because if you keep stacking stuff up there, eventually it falls down.

Preserving the Historical Integrity of a Building

Maher: And how do you balance the aspects of preserving the historical integrity of an old mill building with modern roofing materials and techniques? Or does it matter really in this case because it's just the roofing and the public certainly is not usually seeing the roof of a mill building, so does the historical nature of the building factor into it at all?

Rogenski: Typically, the historical nature of the building doesn't factor into it much except for ... and think of some of these historic mill buildings literally right across the river from you here in Manchester, as long as we're not doing something that alters the outside appearance, like for instance, from the road and that sort of thing. The other thing they typically like is, so there's a lot of different roofing products that we can use, but let's consider two of them, the two predominant ones to be EPDM, rubber, which is, it comes in different colors, but typically gray and black are the most common with black being by far the most common.

And then the other one would be TPO, thermoplastic olefin, which is another far newer product, which has great purposes. Well, a lot of times when you're flying on an airplane, especially down south, you see these roofs that are bright white. You ever notice that, you're flying into Orlando and you look down and there's all these roofs?

Well, that's probably a TPO roof and it's white because they want that reflective quality. We don't really need that here in New Hampshire. We aren't as sun affected. So, the great news is a lot of times what they don't want is they don't want that bright white roof. The great news is things like TPO we can get in multiple colors, we can get it in a gray, we can get it in a black, we can get it in white.

There's also even, if you will, brown bronzes tones to it as well. So what most people want in those historic structures is that our roofing doesn't make it look weird, like you have a 1900 building with this shiny white roof on it. As well as that our metalwork, for instance, if there's parapets, we have to do metalwork on the outside of that, that our metalwork looks historically appropriate. And a lot of that's built around color as well as the design of the metalwork. They're usually not too picky about the material as long as the aesthetic stays intact.

Materials for Roofing Mill Buildings

Maher: Do some of the roofs on the outside use copper materials at all, or was that generally not used in the mill building?

Rogenski: That generally wasn't used in the mill buildings, again, because of costs. So, they were much more likely to be using ... I've seen it in galvanized, a lot of lead was obviously used. We still use lead in roofing, not the way it was used in the past for obvious reasons, we all know a lot more about lead now than we used to. But we have a lot of great options in other metals like aluminum and coloring that we can make it look and we can shape it so that it's appropriate for whatever the visual need is for that building, and it's in a long-lasting material.

We do find some that do require some copperwork, but usually that's more around entryways and stuff where they're trying to have a certain look around the entry. But you get up on a 400,000 square foot factory, they probably weren't doing it in copper back then, just because even then it was pricier than their other options.

Common Repair and Maintenance Challenges for Mill Buildings

Maher: Okay. What are some of the common repair and maintenance challenges that you face when you encounter large industrial style mill buildings?

Rogenski: Sure. Well, because of the roofs, they are typically very large buildings. Those roofs, it's about leaks and maintenance. So, the more square feet of roof you have, the more opportunity you typically have for leaks. Also, if all the mechanical systems are now on the roof of that, you got to remember when this place was built, the mechanical systems weren't on the roof, there was a water wheel driving it and there was no air conditioning, and the heating system was a furnace in the basement that burned God knows what, well hopefully crude oil or worse.

So, now all the mechanical systems have been modernized and moved to the roof, so there's all these penetrations that weren't there before. So, a lot of times the challenges are around leakage, either A, due to the size of the roof, B, due to the proper installation of penetrations around those mechanical needs. And then the other part that comes with that is just the more of those mechanical systems that are up there, the more people are up on that roof.

In the old days, you put down a roof and there wasn't much going on up there except for the maintenance guy went out and made sure that the gutters weren't clogged or the drains weren't clogged. And I don't know, you probably went up there and maybe had a couple of cigarettes to get away from the boss. And now your HVAC team, anything associated with heating, cooling, and a lot of times even some of the electrical systems, are all located up there.

You have maintenance and service workers going through there, dropping, not intentionally, dropping screws, dropping this, dropping that, walking all over the roof and next thing you know, someone who dropped a couple of zip screws, the next guy along walks over them and then suddenly over next to cooling unit six, there's a leak and that sort of thing. So, a lot of it's that maintenance level and staying up on that. So, that's one of the biggest challenges for folks is making sure that they stay on top of those things, catching the little things before they get big.

Planning for Roofing Projects

Maher: Right. And so that leads into how can building owners and managers proactively plan for and budget for roofing projects in mill complexes?

Rogenski: Sure, sure. Great question. We definitely are advocates of roof inspections. So, first of all, proper maintenance is always great. You can have us, for instance, Master Roofers will contract with you to do maintenance on a roof, whatever your desire is, once a year, four times a year, a lot of times it's twice a year where they have us go up, make sure for instance, a flat roof that the drains are properly cleared, if there's scuppers on the outside where drains up, making sure that those are proper, looking for problems.

Do we start seeing, for instance, flashing peeling away somewhere or something like that? So, they have us once or twice a year go up, do a survey, identify whatever problems there are, tell them what it would take to fix those. So, that's how you keep those one great way to keep those big problems or little problems from becoming big problems.

The other thing that you can do is by doing roof surveys on a regular basis, you can start to understand what the lifespan of your roof is. Am I five years away from needing a new roof? Am I 25 years away? And you can start budgeting for those things. So for instance, we just worked with a large manufacturer in our area and replaced their roof, it was, I don't know, 650 squares of roofing, which is a lot of roof.

Well, they had known by working with us from about five years ago that that roof was in its last five to 10 years of lifespan through doing roof surveys. So, they had started budgetarily to accrue and to plan on that roof replacement so that when the time came, they were in a financial spot to be able to do it, it didn't sneak up on anyone. And from a corporate point of view, they could plan for it much better, both budgetarily and physically because of the nature of what they do, they had to do some production line shut down as well. So, they were able to plan and it wasn't disruptive to the business financially or physically.

Maher: Right. The more that you know about what's coming up, the more that you have the ability to plan for it ahead of time. Like you said, you just don't want that last minute surprise where it's like all of a sudden it's hundreds of thousands of dollars or something to replace a roof.

Rogenski: Yeah. No one wants to be the maintenance director that has to walk up to the plant manager and say, "Hey, bad news, we've got to drop a half a million dollars on a roof. When do we got to do it before winter?" But when you can see that coming and literally accrue for those dollars over the course of years, much less disruptive for everyone. And we want to help with that.

People think that we probably like telling people that the roof is end of life, we actually don't. And with our commercial customers, we usually have a long-term relationship, that's what we like to have anyhow. And we want them to be able to plan properly. It's a better way of doing business for all of us.

Innovative Roofing Solutions for Mill Buildings

Maher: Right, absolutely. Are there any innovative roofing solutions that are suited for mill buildings to help improve maybe energy efficiency or even just the overall longevity of a roof?

Rogenski: Sure. Absolutely. So, I had mentioned earlier TPO as a roofing material, TPO, as I did mention, has some great properties for it as far as being able to be sun reflective if you want, if that's a need in your particular space and that sort of thing. So that's great.

Maher: So, is that similar to a rubber roof but it's white, is that what you're saying?

Rogenski: Well, it comes in a variety of colors, but if you want it to be sun reflective, yeah, you can get it in white and it helps radiate back, a lot of that energy that would normally be absorbed by the roof is simply radiated back out like that. And it's actually different. So EPDM roofing, rubber roofing, is rolled out and adhered or mechanically fastened, whatever it is. And then the seams of it are, for lack of a better word, let's call it glued together, okay?

Maher: Okay.

Rogenski: I'm trying to make this in ways that people will understand.

Maher: Sure.

Rogenski: TPO is different, TPO is like, think of it as plastic, it's not plastic, but let's think of it as that. When we do that, we actually have a heat welding robot that we put on there. There's parts of it that we do by hand with heat welders, fine details, but the big long, so if I rolled out a 400-foot-long piece by 16-feet-wide piece of roofing, two of them next to each other, now down that seam we actually heat weld that using a heat welding robot that follows that seam and gives it a perfect well all the way down it. And that's when we're done with the roof, with a TPO roof, it's not multiple pieces that are glued together like EPDM rubber is, which is a tried and true and a good system, the TPO is literally one continuous piece when we're done.

It is that roof has become physiologically one continuous piece, not multiple pieces glued together, which is a really great solution. You also talked about energy efficiency. When people re-roof these mill buildings or any commercial building, a lot of times, especially if it's an older building, there's absolutely the opportunity to add insulation. And a lot of times they can also benefit from rebates or credits from their utility provider by adding to that insulation.

So, when we recently did, it was an EPDM roof that we did for someone and we also did it with, we added ISO insulation to that and we took them from an R of about 15 in their roof which was when the roof was put down 30 years ago, it was probably pretty normal, to an R30 up in their roof by simply adding another layer of insulation, which is tapered also, we have it made tapered properly. We come up with a whole plan for the roof to drive the water towards the appropriate drains.

So, we're not just up there smacking down this foam insulation, the insulation is actually built and made specifically for that roof to taper and drive the water towards the appropriate drainage areas. So, that customer not only got another roof that they won't have to worry about for another 30 years hopefully, but they went from an R15 roof to an R30 roof at the same time. And they're also gaining some credits back as well through their utility provider.

Solar Arrays on Mill Buildings

Maher: Do you know of any mill buildings that are installing solar arrays on their roof in order to get some extra electricity for running the building? And what kind of challenges would that create for a roofing company like yourself in terms of installing or fixing a roof that has solar panels on it?

Rogenski: Sure. So a lot of them, because a lot of these mill buildings are big flat roofs, and it's a great place to assemble solar, whether it's used to run the building, sell back to the grid or however they're doing it. It's not uncommon, and what we really do is we work together, through the building management we work together with their solar provider because we probably need that stuff removed.

Sometimes we can actually work with the solar provider and essentially jack it up, put our product underneath it, bring it back down. And in those situations we really, depending on how it was installed, don't even really need much input except for we want the solar company to come re-inspect when we're done. So they go, yep, no problems here, you did a great job.

But there are other times, depending on the mounting system, where we actually need to have the solar system removed for a period of time, or moved at the very least, and then reinstalled. In those cases, we asked them to work with the solar provider to do that, and if they don't have a current relationship with whoever did that, we also had several solar providers that we partner with that we're happy to refer them to and they can work together to get that accomplished.

Maher: All right, that's great information, Brett. Thanks again for speaking with me today.

Rogenski: My pleasure. Thank you for having me, John.

Maher: And for more information about Master Roofers, you can visit the website at masterroofers.com or call 603-623-4973.