Finding a leak on a tar and gravel roof is usually not too difficult for an experienced roofer like myself. Most times it’s easily found but once in a while it can be tricky for even a seasoned veteran. Persistence is the key. However, difficult was not the case today in Ladner. After sweeping the roof area near the drip location and using our secret tool to find the splits ( I can’t publicly tell you the secret or others roofers might start to use it and gain a bit on our success rate and thus gain on our market advantage too) we found more than we bargained for. The splits kept coming and coming the more we expanded our search area. How was this roof not leaking more than what showed up inside? The answer had to be in the vaulted ceiling and it’s ability to shed the leak water away from the inquisitive home owner’s vision. The photo attached shows the proper way to prep a roof before application of the patch. Yes. Those were some major splits.
There are two main categories of roofing. Low slope and steep slope. Low slope is anything that has a pitch of 4/12 or less and Steep slope is everything above that. Slope or pitch is usually noted in a fraction of twelve. Twelve is used as it relates to the old school measurement of 12 inches. Slope is based on rise compared to run. Rise is how vertical the roof climbs and run is the horizontal distance on an equal plane to the flat ground. So a slope of 4/12 means the roof rises 4” on a horizontal distance of 12 inches (or one foot). So if I may jump ahead and offer this example, a pitch of 12/12 would be a 45 degree angle. This is not a pitch someone can walk on without any form of help or fall protection gear.
The general rule of thumb for usage of roof systems is that everything above 4/12 gets shingled with asphalt, cedar, concrete, clay, metal or composite shingles. Anything below 4/12 should get roofed using a membrane system such as SBS torch on, EPDM rubber, TPO, PVC and the quickly disappearing tar and gravel roof systems. Shingles depend on positive watershed and are not entirely self-sealing. They rely on overlap and gravity. A membrane roof is equivalent to enveloping and is a continuous membrane system with no weaknesses. I have waterproofed planters in torch on membrane and they are continuously holding water.
Now shingle manufacturer’s want us to buy more of their product so they say we can put shingles on roofs that have as low a slope as 2 or 2.5/12. They have their low slope requirements and necessitate changes to the roof system other than what would be done on a 4/12 or greater roof. I have seen it done and it has worked. I exclusively use a GAF-Elk shingle because they are so well self-sealing and become almost membrane like once they have had the heat of the sun to activate the patented Dura-grip adhesive on the back of each shingle.
The steeper the slope/pitch of the roof the less water is going to adhere to the surface and erode the waterproofing material. Therefore it goes to say that a flat roof requires a qualitative waterproofing system as it may hold a large quantity of ponding water for extended durations, depending on the effectiveness of the drain placements. Flat roofs commonly settle over time also (or sag in the middle of the roof area where the structural support is at the least) and when the rigid drain, supported by cast iron plumbing pipes, doesn’t move it results in excessive standing water as the drain is now “high”.
The attached photo shows an interlock shingle application on a low slope roof in which the contractor should have chosen a membrane roofing system. Trust Crucial Roof Services to choose and install your low slope roof system. Roof system selection and integrity thereof is of primary regard in all our roofs installed resulting in absolute customer satisfaction and continued referral business.
When discussing this pertinent issue now days, clarification is needed. With the development of the LEED program – Leadership in Energy and Environmental Design – and the energy efficiency certification available to specific roof systems, a Green Roof is no longer just one specific detail.
It used to be if you had a flat or low slope roof and you wanted to put plants and/or grass on it, it could be called a green roof. I continue to caution people to ensure their roof membrane is in good enough condition to accept the effects of such a plan. The torch on roof system Crucial Roof Services installs is more than equipped to handle the challenges associated with putting a growing medium on top of your roof membrane. The first thing needed, after a quality torch-on membrane roof system, is a drain mat which allows the water to easily flow towards the drain(s). Next we need a root barrier. The goal would be to grow plants that have a shallow and non-intrusive root base, but none-the-less we want to put down an effective root block. Finally you have the growing medium (2-5” deep) and vegetation. This is a pretty simple, and an effective way to lower your heating/cooling costs and contribute to the betterment of the planet. If you choose to go with a deeper growth and larger plants, this is known as an intensive green roof and may require irrigation and a drainage system.
The photo, corresponding to this blog, shows what an unintentional green roof may look like
Now with the development of reflective membranes there is a new and much more regulated and detailed category of Green Roofs. It seems my favourite torch on membrane company – Soprema – is leading the industry in this emerging field. Soprema’s website is an excellent source of information. To start your education off it must be known that there are 4 categories of LEED Certification – Certified, Silver, Gold and Platinum…. and it just expands from there. I’ll just touch on one small aspect of the whole LEED program. Follow this: There are the various membranes which are given “credits” or “values” for certain characteristics. These qualities or characteristics are more than just the energy efficiency or reflectivity of the product. For example, the environmental “footprint” of the membrane is calculated from the production point to its final destination and such factors as, material make up (and if recycled contents exist), whether it was shipped by train or truck (which have different effects on our environment), and even the carbon credit of the factory is considered in effecting the value or credit the material achieves.
Contact Crucial Roof Services for further information about torch down roof systems.