HEAT CABLE INSTALLATION on slate roofs: As there is an ice buildup at the edge of my roof, I just installed a heating electrical wire running over the slate tiles and back in the gutter to prevent the backflow water dripping through the roof that happened last year. I wonder if you would have any recommendation on the matter, and especially if you think my installation might somewhat ruin the slates.
TR: When installing heat cable, we drill a 3/16 inch hole in the bottom corner of the slates, then run a copper or stainless wire through the hole to tie the heat cable to the roof (see photo above). This enables you to attach heat cable without puncturing the roof and causing leakage. Otherwise, oversized bib flashings installed throughout the ice dam prone area will often solve the problem. Please read the article about ice dams on slate roofs in this issue.
AUSTRALIA: Just like to show some of our work in Perth Western Australia (photos below). First, second, and fourth are of St. Georges Cathedral in the city and the third one is of a copper hip fixed with stainless stiffeners so no fixings are visable. Picture four is of me on the roof at the Cathedral. All slates are Burlington from the Lake District in England. Nigel Carter, Carter Roofing and Slating Pty Ltd, Australia; carterroofing.com.au
SCOTLAND: Your website and Traditional Roofing Magazine have been a tremendous source of information and inspiration. My house (photo below) is the ONLY one in the street that retains its original features; slate roof, coronets, sash windows, chimney pots and stacks, wooden fascia... 90% of people in the town doing building work on old properties are having some or all of these removed. After reading your articles I realized that it was possible for me to do a restoration job in the traditional diminishing or graduated style and I will be starting ASAP. My father found an old book at a church sale “The Technical & Instructor” by William McQuhae published 1892 (see PDF). It has a short section on slating and is a genuine snapshot into a bygone age. It may be of interest to your readers? Alistair James, Argyll, Scotland
TR: See excerpt from “The Technical and Instructor” on the PDF.
STAGING FOR STEP FLASHING on slate roofs: I will be helping on a new construction slate roof. One question I had was installing the copper step flashing. My problem is that the stucco or siding crews will have to go over the flashings against the wall. I know the slates can not be walked on. What is the best way to approach this situation? Should I Install ladder hooks so the siders can come in after we are done?
TR: You can stage alongside dormer walls either by using hook ladders (easiest, if there is a horizontal ridge above) or installingand planks with ladders sitting on them. It depends on the roof jacksconfiguration of your roof. There is a video clip showing the use of roof jacks at SlateRoofCentral.com/videos.html. Roof jacks (roof brackets) and ladder hooks are available at SlateRoofWarehouse.com.
SNOW APRONS AND PEEL-AND-STICK: I live in Vermont and have a slate roof. The house was built in the 1930s. We're having a roofer install a snow/ice belt along the edge of the roof where we've had leaking. He says he'll put "paper" under the slate, not the ice shield. Do you know whether the ice shield is better than paper? He says the slates stick to the ice shield and, if/when you have to replace the slates, they'll break because they stick to the ice shield.
TR: There is no reason to install ice and water underlayment under a metal snow apron, unless you're expecting the snow apron to leak. However, metal snow aprons benefit from red rosin paper installed underneath, as this makes it easier for the metal to expand and contract. We typically use 30 pound felt underlayment, then rosin paper over that when installing a metal snow apron. Self-adhering ice shield is unnecessary and your roofer is correct — it makes long term maintenance of the roof more difficult. See the article about installing snow aprons on slate roofs on page 23.
CAN’T GET THE SOLDER IRON HOT ENOUGH: I can't get my solder iron hot enough to get a smooth joint. I switched propane tanks. I waited for a warmer day (sunny and 45 here) and I've cleaned everything I could. Help!!! I've got 4,000 square feet of roof in front of me!
TR: Check to make sure the iron & regulator are running at full blast with no obstructions in the orifices or hoses. Use a tank that was filled when it's cold outside to avoid pressure discrepancies. Keep the tank & torch warm when not soldering (i.e. inside heated space at night). Slow way down and get a good molten solder puddle to allow the iron to conduct more heat. Make sure there is no water or moisture in the underlayment, and that the copper is isolated from stone and masonry as these conditions will rapidly wick heat away from the joint. Make sure to use 50/50 solder. If the above doesn't do the trick, get a Sievert torch, it just pumps out the heat and the tips have much greater mass. Above being said, even the Sievert propane soldering iron struggled to put out enough heat to do a lap seam when it was 25 degrees F on a 15 mph windy day, seven stories high. Here is a good source of soldering irons and solder supplies: SolderWarehouse.com. [Thanks to Chris Paulin of Paulin Slate and Copper for this answer!]
THANKS FROM A GRATEFUL READER: “I want to thank you a lot for instilling confidence in me, and other DIY roofers that want to learn the skills of quality roofing, by providing the abundance of slating information you have. I spent the weekend replacing some hideous green asphalt junk on a section of my 125 year old roof with some decorative fish-scale slate I got from a local salvage man. Not only did I cut the fish scales myself, but I installed them as well with the help of a friend who's had experience with modern roofing techniques, but never slate. I had to correct him on some things I learned from your website and book, such as decking material, nailing techniques and use of drip edges. I inadvertently learned how to properly remove and install shake siding too because I had to remove three layers to remove the rusty, pitted flashing. This winter will tell if we did a good job or not, but even if we messed up somewhere, I at least have the confidence to repair my own mistakes now. I wish there were more websites & books like yours...”