Vancouver tile roofingToday’s concrete tile roofs, cement tile roofs and clay tile roofs are rarely installed according to current known and best practices in the Lower Mainland Area. What I mean by that is ideally one should install a tile roof system over top of a sheeted and waterproofed layer of plywood. This is rarely done due to the costs associated with this degree of waterproofing. We commonly see an underlayment sheet, draped over trusses with 1×4 cross straps nailed over top of that. These cross straps are hopefully spaced accordingly to allow for a 3” head-lap between rows. A good salesman calls this underlayment draping a waterproofing, but that is giving it far too much credit. If it is a waterproofing why is there all these nail holes in it and why are the vent protrusions not sealed to the vent pipe? In some cases it is an organic cardboard which will deteriorate and rot over time and in other cases it is just a thin sheet of polyethylene (clear plastic) which only lasts a couple years until it dries up and disintegrates. Simply put – the underlayment is merely a stop draft addition and should not be given much credit as a membrane.
If I was to build a house and wanted to put on a Monier or Columbia tile roof system, here is what I would do. Sheet the rafters, making a deck surface of ½” plywood and H-clips. Install a peel and stick waterproofing system. There are many acceptable products to choose from by every manufacturer known. Ensure that, at this layer, I am 100% watertight at all transitions, protrusions and terminations. Now, install 2×2 runners up the existing rafters followed by gridding your roof using 1×4’s and allowing for the required 3” head-lap suggested by manufacturers. Your tiles can now be installed.
The finishing details would be as follows – I want to use a 26 gauge drip edge flashing at all rake and gutter edges. All tiles in contact with a hip shall be cut accordingly and fastened to the 1×4 strapping or the hip rafter so as to not fall out of place, or slide down, as is too commonly witnessed in the Vancouver area. I want lead cover patches on all my multi-tile intersections. I want containment lips bent on all my galvanized vent flanges. I want gooseneck vents used to ventilate my attic space. I want lead stacks for my plumbing vent pipes. I want to use 26 gauge metals on my valley flashings. And finally I want to use a pan flashing network around my skylights and grind out the underside of the tiles so they don’t compress the containment lip over time.
If you’ve got a concrete, clay or cement tile roof and want an assessment to learn what needs to be done to reduce the probability of leakage, contact Crucial Roof Services at your soonest convenience.