| Author | Message | ||
     Godsil |
One of my mentors suggests ice and water shield underlayments for a small copper bay. The other insists upon rosin or 30 lb. felt. Who is right? | ||
| Walter |
Mentor number 2. | ||
| admin |
Copper needs to expand and contract. That's why rosin paper is used underneath it. 30 lb. felt under the rosin is standard procedure. | ||
| Renee Williams |
Has anyone heard of 60# Versabase Underlayment? | ||
| jamie callan |
I have installed several flat seam soldered copper roofs. My technique has developed through the knowledge and practice of a couple of respected roofing contractors in new england. My standard practice is to install 3/4" cdx plywood over the original sheathing, then grace ice & water shield, and then the copper. After reading some of these messages I am second guessing this method. What is the right way? | ||
| admin |
The standard methodology requires a slip sheet such as rosin paper between the metal and the roof so as to allow the metal to expand and contract, as it will (slightly). IWS will cause the metal to adhere to the IWS underlayment and impede the movement of the metal, which could strain the solder joints and create leakage. The best method is to use tongue-in-groove lumber (boards), or just butted boards if not T-I-G, cover that with 30 lb. felt, cover that with rosin paper, then the soldered seam copper. | ||
| Jamie Callan |
This is a great site, thank you to all for sharing your knowledge.I think i will try the rosin paper, there is nothing fun about installing ISW, it is very expensive, and obviously our roofs should not leak. is there any other published support of this practice? | ||
| Mark Winter |
Hello, I have a slate roof with several low pitch (2 in 12) shed dormers. The low pitch areas are interlocked flat seamed and soldered copper pans. I need to provide several new penetrations for a soil stack and two bath fan exhaust vents. The latter are 6" and 8" in diameter. I have been unable to locate a drawing of a suitable flashing detail, especially for the base flashing. The existing penetrations were flashed with collars and base flashings fabricated of soldered sheet lead and installed in the normal fashion as the individual copper pans were installed. For the new work is it even possible obtain proper weather tightness on the upslope portion of the base flashing? I assume that my only option is clean the existing copper roof deck very carefully and solder the entire base flashing down to the deck although I am worried about expansion and contraction fracturing these joints. I live in Detroit Michigan. Please advise. Thank you very much. | ||
| Joe Jenkins (Admin) |
Fabricate your pipe sleeve out of copper by rolling it into a tube of the correct diameter. Leave it a few inches too long. Solder the seam that runs the length of the tube. Notch the bottom edge of this pipe flashing about 3/4 of an inch deep every inch or so all the way around (the bottom edge should be angled to fit the slope of the roof). Bend these tabs out flat. Sit the pipe flashing over your pipe onto the existing roof (assuming the pipe is now penetrating the copper -- it should be a close fit through the copper roof). Mark where the tabs are against the copper roof. Remove the flashing and then use a brass wire brush on a drill and grind the copper clean where the pipe flashing will sit on it. Set the flashing back down, rivet it with a copper/brass rivet on *every* tab, then flux it and solder it with 50:50 lead/tin solder. Fold (pound?) the top of the copper pipe flashing down over the pipe to finish the job. The exhaust fans should also be vented out via a pipe. Use the same technique to flash them. | ||
| Anonymous |
OR put the pipe in and install a pre-made copper boot with a rubber gasket flashing seal that goes around pipe (pipe should be pvc) and pop riviot, clean around (old copper) with a brass wire brush on a drill and solder around complete flashing boot to roof. Using same methods and type solder as Joe stated. |
