Low Slope Roofing- Choosing the Right Flat Roof Membrane

General Roofing Systems Canada provides low slope installations throughout Canada. Low slope installations are completed in the following cities; Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario

The inquiry below came in to our call center today, we thought it best to post it as an article to our blog to assist others who have questions regarding Low Slope Roof Membranes.

The email conversation below contains standard questions and answers that our clients have when choosing the correct “low slope roofing” or “flat roof membranes”.

The following items are a listing of the topics covered amongst the email; low slope roof life cycle costs, choosing the right roofing contractor, low slope roof prices, roof installation quality, choosing the right flat roof membrane, differences between various flat roof systems, and many more.

RE: A roofers perspective of low slope / flat roof costs, life cycle costs, torch down 2difference between flat roof systems, and most importantly  roof craftsmanship.

Email Conversation:

Hello,

I am presently in the middle of preparing to build a new office space with a low slope. My architect was advising the TPO material for it being more “green” and its heat reflection.

 However,in my internet search, the results and outlook for TPO roofs is still in question. I am looking towards the old standby 2 ply SBS and I writing this letter to you as you do all these products.

 Which one would last longer and what is the cost difference between the 2 products… also include PVC if you can.

 Regards,

 

Dear valued client;

Thank you for your inquiry.

We have been receiving a lot of the same sort of inquiry lately (what are the cost of flat roofs, the life cycle cost of flat or low slope roofing, and the difference between low slope or flat roof membranes).

Generally we tend to receive these types of inquiries at this time of year, this is primarily due to commercial, industrial and home owners having time to complete research as a result of the holiday season.

With saying that, I am going to post your questions about low slope roofing to our blog along with my answers (in article form) so that our conversation(s) will assist others when researching about low slope roof membranes and roofing contractors.

Your “Roof Life Cycle Cost” will be determined as follows: 90% will be a result of the roof installation quality and 10% will be determined from which low slope roof membrane is selected.

For every ten hours you put in planning for your new flat roof, nine of those ten hours should be researching and selecting the right contractor for your project. If you put in a total of 5 hours planning your flat roof project, 30 minutes should be spent considering the different flat roof membranes available and 4.5 hours should be spent researching, selecting, and communicating with your new flat roofing contractor.

The most important aspects to considering a Flat Roofing Contractors is; Roof Workmanship Quality, WCB, BBB reports, Insurance, Liability, Warranty, Guarantee, Safety programs. Although it is not necessary that the flat roofer is a member of the BBB because complaints can be lodged whether a company is a member or not.

Random consumer complaints are not that important due to the fact that anyone can rant about anything online (It is impossible to make everyone happy 100% all the time), yet complaints to the BBB should be given serious consideration as the BBB has a highly professional process required for authenticating complaints.

The workmanship guarantee is to be considered one of the greatest factors to take into consideration.  In some ways this is even more important than the roof membrane manufacturer warranty.

Alongside this there are other considerations to keep in mind such as insurance coverages for example:

A) Work Safe / WCB clearances (you are able to get one from Worksafe / WCB),

B) Commercial Liability Insurance (which should be 5,000,000.00 – some go as low as having only 2,000,000.00 insurance),

C) Roofing Contractor’s Safety Program (which ensures the workers are actually being safe while on your site including the use of hard hats, vests, harnesses, daily hazard assessments etc.)

These are all important considerations that help protect the customers. An injury to a worker can be a significant issue for a home or business owner if the roofing contractor has not followed the proper compliance procedures. Such an event like this can cause you considerable expense and aggravation.

TPO Roof Life Cycle Costs

Now in regards to your question pertaining to TPO Roofing and life cycle costs, unfortunately this is still unknown. Perhaps not scientifically, but from a flat roof installer perspective it is.

Statistically speaking, we have more data specified to PVC roofs than we do TPO. The reality is that all low slope roof membranes have similar life cycle costs. Yet when you consider them statistically or scientifically they do vary, but all in all, low slope or flat roof membranes all perform quite well.

However, coming from a “roofer’s perspective”, here is what I can tell you; An issue that we as roofers see every day on the roofs, which in truth should be your highest priority in research is the actual installation of the material itself. Numerous building and home owners alike are unaware of the actual process, procedures and potential roof failures due to improper installation of the flat roof.

Another area of concern is the other workers that will attend the roof during construction or after, such as HVAC installers for an HVAC retro-fitter.

Now with the assumption that the contractor is reliable and adheres to all the proper regulation, the reality is that things can happen when a flat roofs are being installed. No company is flawless and has a perfect flat roof installation every-time.

In the offices, we here several conversations about how things can and do go wrong, yet it is how we deal with the problem that separates us from success or failure with other roofing contractors. We see time and time again, people that do not do their proper due diligence because they assume things should just go without incident. Although this is not like buying a car. Hiring a trade is much different.

Of course on the other side of managing roofers or the installation of flat roofs is that there is the pro-active side of things that says there are things that we can do as the roofing contractors before problems arise to assist in a higher probability of a proper roof installation occurring.

Now, in our instance we have done things like institute our industry with an Unconditional Lifetime Guarantee which causes our roofing staff to be more aware of the day-to-day incidents that could occur. It is our responsibility to provide superior roof craftsmanship. This has our staff in a more stringent project path for a flat roof installation quality control system. Ultimately, the craftsmanship itself is what most determines the true cost of your flat roof and not which flat roof membrane or flat roof system was chosen.

Once you get past the issue of the quality of installation for your roof and hiring the right contractor you can then consider which roof membrane to use.

Now to provide some answers specific to your questions, here are some considerations for your low slope roof membrane research;

 

With respect to traditional low slope roofing (SBS, TPO, PVC, EPDM, BUR) I would recommend using 2 ply SBS modified with complete confidence.

The reason is that with a single ply, you have opportunity for what we call catastrophic Failure. In other words, a hole the size of a quarter in the membrane can cause significant damage to the complete system as the water can travel. With SBS, it is torched down and the opportunity for water migration is less. Here’s one other factor to consider with SBS modified, if you have roof installer that does not install the membrane correctly, this will result in you having significant issues. The deficiency list can be considerable and cost more than replacing the roof in the first place.

Now, You didn’t ask about multi-ply low slope roofing specifically, yet I am going to take the liberty of giving you a couple of thoughts regarding those systems. You are able to get a multi-ply low slope roof like the Tough Roof System that will give you the reflective values you desire. Additionally, you will get the sense of security knowing your roof will have maintained durability. The Tough Roof is a multi-ply built up (BUR) roof system that has layers of bitumen (in this case a synthetic layer in between instead of the traditional felt mats between each layer) and on the top, Tough Roof uses white elastomeric roof coating which contributes to the reflective component.

The other option you have in these newer systems is a multi-ply liquid rubber system which is VOC free, completely environmentally friendly and you can cover it with an acrylic reflective top coat. The system is a proprietary system from General Roofing that includes 2-4 layers of liquid rubber with a synthetic fabric between layers of built up and with an optional top coat of acrylic reflective roof coating. Of all the systems you can get, this particular system is most environmentally friendly, it is bullet proof like the built up roofs, and it can be as reflective as you choose.

So ultimately your choices are; traditional 3-4 layer built up roofing (Tar and Gravel) which is 3-4 layers of tar with tar felt paper in between, then the 2 ply modified bitumen which is torched down, the single ply roofing (EPDM, TPO, PVC) which is mechanically fastened, fully adhered, or ballasted, and then the newer type of built up roof like the Tough Roof which is 3-4 ply of tar with synthetic fabric between the layers with an elastomeric top coat for reflectivity and the newer built up liquid rubber systems from GRS that are 2-4 layers of built up liquid rubber with a synthetic fabric between the layers with the option of a reflective top coat of acrylic elastomeric roof coating.

From least expensive to most expensive the roof membrane systems typically go from least expensive to most costly as follows; Spray Foam, EPDM, TPO, PVC, 2 Ply, GRS Liquid Rubber BUR, Traditional BUR, Tough Roof. However, it is important to note when considering the cost of a flat roof or a low slope roof system two things. First, the cost difference between flat roof systems as you go from one to the next is small in comparison to expected life cycle cost planning. For example, EPDM roofing is moderately more costly than Spray Foam, and PVC moderately more cost than TPO and on and on as you go through each system. Yet the important consideration is the cost of the roof over a period of time. A properly installed Tar and Gravel roof or properly installed 2 Ply SBS Torch on Roof will likely last much longer than EPDM, TPO, or even PVC – “likely” has a number of considerations…. weather, application, service workers on the roof, etc. And a Liquid Rubber Built Up Roof and the Tough Roof built up systems have almost unlimited life cycle as they both come with maintenance agreements to renew the top reflective layer of elastomeric coating.

I hope this has helped answer your questions, please feel free to contact us any time should you require more information or would like to ask us more questions.

Until next time

The staff at GRS

 

CONTACT US:
General Roofing Systems Canada (GRS)
24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free. Email info@grscanadainc.com

Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario.

 

Re-Roofing: Applying Shingles in the Winter

General Roofing Systems Canada provides re-roofing services throughout Canada. Re-roofing projects are completed in the following cities: Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario.
Applying Shingles in the Winter? Roofing Contractor Guarantees? Attic Condensation? Roof Venting? 
The re-roofing post below is a continuation of an article written earlier this year that represents our discussions with a homeowner’s frustration due to an improperly installed re-roof.
On Wednesday, Nov 23, 2011 at 9:36 AM, our client wrote:
Hello,
I have a bunch of questions/concerns:
We were wondering what happens when we book a week and then that week turns out to be snowy or really cold, especially if that happens part way through the job?  Under what conditions do you not work? Do we have to be there when the work is being done? Our roof already has snow on it and because it is metal; it is very slippery. When our metal roof was being installed, the previous owners said that the roof was exposed during a rainstorm and it caused water staining on our walls.  I doubt we will get rain but will snow cause issues if you are part way through the job and it snows?  Do you do it in sections so that the roof isn’t fully exposed? Would a roof that is installed in the winter be any different in performance or workmanship than a roof installed in warmer temperatures? Will the high shingle cap be adequate for ventilation? And if it isn’t, what happens if we have problems? We are just concerned that we spend all of this money and we end up with a roof that still causes us problems.
For payment: I see at the bottom of the quote that you take VISA. What other methods of payment do you take?  I don’t think my credit card limit goes that high so could you combine credit card and personal cheque? Does payment happen after the job is completed or do you require a down payment?
We have company from Nov 29th to Dec 13th (not sure when they are leaving).  Does the 13th work, or will you be available early into the new year?
Our Response:
Dear —,
You have some very good questions in regards to the re-roofing process. There are many homeowners that rush into a re-roofing project without all the correct information. This unfortunately causes them to realize later on that something was missed, misrepresented, or simply should have been discussed.
With respect to how weather affects the shingle process with your home, more specifically in your instance , how winter roofing affects the shingle application. We have an off-site section of our main website that provides information regarding how to shingle a roof. This also details some examples of completing this type of project during the winter months.
Now with winter weather, especially the bitter cold or periods with large amounts of snow, this can push our crew schedules back across the entire company. Although with that being said, the winter can actually be a better time to complete a re-roof project as we don’t have to worry about the rain.
However, winter shingle application can only be completed with if the temperatures stay above  -18 C or better.  Applying shingles at temperatures below the shingle manufacturer’s recommendations can void your warranty.  Most manufacturers mandate installations above -18 C.
The perfect temperature for re-roofing shingles or the actual process of the shingle application is -10 to +10 C. Shingling is best done when it is not too cold as shingle nail blow-through occurs with brittle shingles (leading to shingle blow-offs when high winds come). Nail guns don’t fire properly in the extreme cold, and roof nails may not sit flush as the ice on the shingles may hinder the nails from sinking into the shingle and roof deck correctly. This is only one example of the various problems that could arise.
In continuation to the temperature, it is also preferred for it to be not too hot. If the temperature is too hot, this also causes damage to the shingles due to them cracking underneath our roofers feet. So the idea is to pick a week that has moderate temperature. We prefer late fall, winter, and early spring, yet with moderate temperatures preferably between -10 and +10 c. The snow on the roof is not an issue at all with re-roofing (unless it’s really extreme) as we close up what we work on everyday with the use of proper roof tarps, and if required, roof connections, etc. Sections of the roof are done one-by-one.
With regards to your roof venting and/or antic ventilation, proper roof or attic ventilation is more specifically assessed when the old roof material is removed (air intake at the roof soffit, air exhaust at the roof vents and/or ridge venting). If the roof’s ridge vent allowance at the peak is not appropriate, our roofers will cut back a half or full inch or whatever is required from the roof sheathing that meets at the peak.
The truth is that we guarantee our roofing workmanship for the lifetime you own your property.  We have a proprietary shingle application method that enables us to do this. However, we do see some instances where condensation issues in the attic or roof system continue post re-roof. No roofer, building envelope consultant, or engineer that I have met or roofed with know for sure what will happen, and no roofer can honestly guarantee that roof or attic condensation will not be a problem after the re-roofing is complete.
When our crews have completed the re-roofing there will be no leaks. The workmanship, roof application methods, and our exclusive specifications are guaranteed to be the best you can get in the roofing industry. The roof ventilation will be installed directly to code, and the roof shingles will be of a very high quality (search our blog for Malarkey, for example).
One consideration to keep in mind is the fact that roof or attic condensation can be caused by a plethora of building envelope scenarios. There are several roofers that leave potential customers feeling at false ease prior to starting a re-roof. They do this in an attempt to mitigate issues that may arise with condensation in the future.
Now in regards to payment for your re-roof, we do honour all credit cards and cheques upon completion. We do not take a deposit prior to the start of a re-roofing project . When the work is complete and you are completely satisfied, we then request payment in full.
A final note to scheduling your re-roof, we have a lot of flexibility from December 15 to February 15 each season. We can work around your schedule.
Thanks again for the great questions. Should you have any more, do not hesitate to contact us again.
Untill the next time,

The Roofers at GRS

CONTACT US:
General Roofing Systems Canada (GRS)
24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free.

info@grscanadainc.com.

Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario.

Metal Roof Repair or Replacement?

General Roofing Systems Canada provides metal roof replacements throughout Canada. Metal roof replacements are completed in the following cities: Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario.

Metal roofing is a vague word in the roofing world as it can be used to refer to a variety of systems. There are metal roof shingles, steel shingles, metal slate profile shingles, metal shake-looking shingles, metal panels, standing seam metal roofing, corrugated metal roofing, metal roof tile that are coated with granules… you get the point. The options in metal roofing are almost endless now.

One consistency that remains among the variety available to you is this: metal roofing can last longer than any other kind of roof’ however, a metal roof that is installed incorrectly will only last as long or be as durable as the workmanship of the install. If the underlay, or the venting of the roof system/attic is not correct, then problems such as leaking and ice damming will occur. With the weather that we have been receiving this year, one might see their metal roof may leak in multiple locations as time goes on. It is a frustrating experience living under a metal roof that has not been installed correctly.

To Repair or Replace?

Yesterday we had an inquiry come into our call center that is very common for us to receive. We felt this particular case would be a good addition to our blog in an attempt to help clients in their future endeavours while completing roof projects. 

On Monday, Jul 25, 2011 at 1:27 PM, the client wrote:

Hello,
We have an interlocking style metal roof that was installed by company 5 years ago by the previous owners.  The roof leaks in the winter as a result of ice damming in the valleys, and in the spring shingles annually become loose (and have blown off) on the edge of one of the valleys from the ice sliding off.  I am tired of dealing with the company (long story) and we are wondering if there is any way to repair rather than replace what they did.  We have a log house with cathedral ceilings so I suspect we need to try to improve the airflow under the existing metal shingles. I don’t know what it looks like between our open ceiling and the metal shingles above (regarding insulation and air flow). There is no venting other than vented soffits (as far as I can tell). Is there any way to seal the metal shingles so water doesn’t flow back up under them?  I don’t know if any waterproof barrier was used in the valleys and I don’t think the roof was installed very well in some parts. After talking with the previous owners a couple years ago, I know they weren’t satisfied with the installation of the metal roof, but they ended up having to relocate before going through a winter.
A couple of other things to note;  a few of the metal shingles were damaged when we were trying to remove the ice from the roof this past winter, and when we had heavy rain, the water comes off the roof before making it to the eaves.
I attached a couple of pictures of the roof so you can see the design.
Based on these pictures, if we had to replace our roof, what would be our best options (type of shingles, venting, etc.), and how could we reduce the potential for ice damming and leaking? How much would you estimate replacing a 1400+ sq. ft. home’s roof with different types of materials?  Is there a guarantee on the ice damming/leaking after the roof has been replaced? Is there anything else I need to know or can I provide you with more information?
Our Response:

Good morning,

I’m the Project Manager for GRS. I travel across Alberta solving roofing problems. However, it’s peak season and I may not be able to get out and take a look as quickly as I would like. That being said, what I am going to do is send this email to our two senior sloped technicians/foremen at GRS as well as our scheduling manager.
Our scheduling manager will keep you informed on our work in progress, and either myself, or one of our foremen, will come out to meet you. In the meantime, I’ll offer for them to chime in their input based on your email and photos (great email by the way – it helps us a lot).
Here’s is my opinion in regards to your questions….
1. From the perspective of someone that sees literally thousands of roof problems a year, my first advice would be to not listen to just any idea of repair from just anyone. Metal roofing is a specialty. A very common thing we see is homeowners trying different “metal roof” contractors in haste and it tends to end with negative results. Both of our foremen are very senior technicians that would not have you running around a circle. If we don’t get to you as soon as you like, and you hire someone else, please make sure to validate the experience of the technician. It would be more beneficial to be thorough with your next selection as any experienced person can rattle off hundreds of client situations and references. In our case, we lay out our experiences on our blog to provide our clients and future clients with quick and easy access to references.
2. I think the end result of your situation is going to be a new roof replacement. Now I understand this is not what you want to hear, and you may find it convenient in a consumer’s mind for me to say.  However, I will explain the reasoning behind my conclusion. We don’t need to sell you a roof, we’re always over-booked so the motive isn’t there. Secondly, we see these installation issues all the time; our blog is full of how to do it right – and when it isn’t done right, it is almost impossible to correct. However, in saying that, both myself and my technicians may assess your building and be able to find a less expensive solution.
3. Based upon your descriptions, I am thinking that it is an inherent design/installation issue. Metal expands and contracts and is a water shed system – not waterproofing. The roof underlay installation is flawed at the valleys. At minimum, I would think the valley areas would have to be ripped out (probably 5 feet on either side) and proper underlay installation executed and metal tiles put back in or new metal tiles placed.
4. Even after doing all that, it is a low slope roof, and you may have intermittent issues either way. That is how I end up at the roof replacement as an end result.
5. With respect to ventilation, that likely could be assessed over the phone with one of our foremen.
So I may not have helped or may have, but the bottom line is that typically the best thing to do is to start over with a roof replacement. Get the underlay, the ventilation and the water shedding product right. Once this has been completed, I believe your issues will be resolved.
Thanks
 Client Response:
Thank you for replying so quickly.  I suspected that we would have to replace the roof.  This isn’t a rush job, but if we could get it done before snowfall, that would be great. If we have to over-winter this roof again, is there anything we could do in the valleys temporarily? Like heat cables or….? The interior log walls got water staining on them last year and I am concerned with the condition of the wood below the metal tiles in the valleys.  In the case with a low sloped roof, would asphalt shingles be a better alternative to metal?
Please put me on the waiting list for an assessment.
Our Response:
 

Good morning,

No problem. The day’s just getting going here so I had the time.
With respect to roof replacement before winter, yes this is very possible. However, I would like either one of my foremen or myself to look at your property prior. I would like to make an attempt at finding a less expensive solution.
If for some reason you were thinking of not approving the work before winter, heat cables aren’t a good solution. Short of using a high quality tarp on your whole roof, it won’t help.
Metal roof systems are fine as long as the underlay is correct. Shingles won’t leak as easily, but don’t last as long. Any roofing product will work as long as the roof underlay and venting is correct.
We will get out to your property as soon as possible to meet you and take a look.
Thanks

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CONTACT US:
General Roofing Systems Canada (GRS)
24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free.

info@grscanadainc.com.

Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario.