| Author | Message | ||
     Anonymous |
Older plumbings systems tend to have cast iron waste lines. I would think that galvanic corrosion would occur by putting a new prefabricated copper or lead vent flashing (as it is well illustrated in the most recent edition)around the cast iron? What am I missing and if it is okay to put lead or copper around a cast iron pipe, which metal is more preferable? Also, there are different size tips that you are now selling for soldering. What potential situations would dictate a certain sized tip? And finally, are mirco-lam boards available at lumberyards or roofing supply stores? | ||
| Walter Musson |
Most pre-fab flashings would have a neoprene insert with the metal flashing which actually comes into contact with the pipe itself. Therefore there shouldn't be a reaction since dissimilar metals are not in contact. You can also cut the cast in the attic and add a hubless connector so that the right sized PVC pipe can be used to go thru the roof and then flashed.When I do this I usually paint the plastic black so it's not so obtrusive. | ||
| admin |
Neither lead nor copper pipe flashings seem to affect the cast iron pipes, according to field observations on old roofs. This is probably because the metals are not in close contact and are not wet between the flashing and the pipe. The neoprene flashings prevent metal to metal contact, as Walter has said. Different soldering tips can be used for different applications. Larger tips hold more heat and hold it longer. You may need this under cold and windy working conditions, for example. Also, it's not a bad idea to have an extra tip in case you wear one out. Microlam boards can be bought at regular lumber yards. |
