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.