Replies

1. 
   davidmeiland | Apr 06, 2004 04:45pm | #1

   Why not talk to the manufacturer of the roofing and find out what they recommend?

1. 
   eggdog23 | Apr 06, 2004 04:51pm | #2

   http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=41708.1

1. 
   davidmeiland | Apr 07, 2004 08:21am | #3

   OK... so... ?

1. 
   seeyou | Apr 07, 2004 02:57pm | #4

   Most copper roofs are manufactured by a local sheet metal fabricator/roofer. For instance, I fabricate for my own crews and some of my competition. I form roof panels the old way with an apron brake. There are outfits that have panel machines similar to continuous gutter machines that pull up to the job site and squeeze out what ever you need. These are normally used in commercial applications.

2. 
   seeyou | Apr 07, 2004 02:58pm | #5

   3/12 is the normal break point. Normally, any lower pitch than that and I switch to flat seam. If it's being installed over unheated space, you can use standing seam, but the installation is slightly different. Instead of locking one pan directly to the top of the lower pan, a cleat should be soldered on to the lower pan several inches below the top of the pan. The upper pan locks to the cleat. If the total width of the porch is less than your bending capabilities (10' in my case), then this is not a concern. Lateral seams are where the leaks will develop. Soldering the lateral joints will only work temporarily as the lateral joints are designed as expansion joints and will break eventually. I would also install ice barrier membrane to the entire roof before installing the copper.

1. 
   VaTom | Apr 08, 2004 06:45am | #9

   If the total width of the porch is less than your bending capabilities (10' in my case), then this is not a concern.

   No brake lives here.  I make pans with tongs.  No lateral seams.  So I could do a minimal pitch?  Not inclined, but interested. 

   I put EPDM on my mother's porch.  Pitch was 1½" in 12'.PAHS Designer/Builder- Bury it!

1. 
   seeyou | Apr 08, 2004 01:58pm | #10

   I make pans with tongs.

   Boy Tom, you're a renaisance man, aren't you?

   I assume you're using roll copper, rather than sheet. The lateral seams act as expansion joints, so if you use pans much longer than 10', eventually the expansion/contraction cycle will tear your naildown clips loose. On commercial roofs where the pans run the length of the roof plane, special expansion rocker clips are used, as well as big ridge covers to let the copper move. I've seen cases of full length pan roofs with the ridges rolled, that have torn themselves loose. I was at Biltmore when they were replacing the lead coated copper roof around the attrium. They left a full 2" expansion gap around around the perimeter.

   In the old days, when terne roof pans were formed the way you're doing it, they flat locked many terne plates together in the shop and created rolls the length of the roof plane. These rolls were then transported to the roof and tonged and seamed in place. The flat locks between the terne plates created expansion joints.

   To answer your question, I don't like to put standing seam over a heated space at less then 3/12. I'll go down to about 2/12 over a porch and 1/12 if my total run length is less than 10'. This is bending SMACNA guidelines a little and these are not hard, fast rules. Sometimes I swing the other way on SMACNA guidelines depending on the situation.

   I'm still getting cu for a little less than $2/lb, but I'm having to play 2 distributors against one another to do it.

1. 
   VaTom | Apr 08, 2004 07:00pm | #11

   Boy Tom, you're a renaisance man, aren't you?

   As in the age of my tools, or my varied interests?  <G>  I don't do this stuff for clients.  It was my luthier buddy, currently visiting Richmond, who got me going.  His tools.  I'm finally getting back to finishing my construction this year.  Copper roof's for a 4½ story lumber "shed".  Makes sense to me.  Wait'll you see the vintage cupola (with electric windows) headed up there.... 

   Anyhow, heated spaces ought to be underground, IMHO.  Much simpler roof.

   Thank you for the lateral seam explanation.  The roof that survived the hurricane has 12' pans IIRC with fixed cleats, out of coil stock as you surmised.  I only use the 3'x10' sheets for siding.  This building will have 11' and 13' pans on each side.  I broke it up for aesthetic, and practical, reasons.

   JoeH was kind enough to send me a book from the Copper Development Association in London, 1963.  According to it, we've been overdoing the cleats.  They say "In addition, flat roofs as low as 2½° in pitch could be covered with copper strip without the necessity of using drips at every 10 ft. across the slope of the roof."  They also address using brass screws, which I'd wondered about.  There's an excellent description of combining expansion/fixed cleats, good for pans up to 28'x2'.  That's bigger than anything I want to haul up to the roof.

   PAHS Designer/Builder- Bury it!

1. 
   seeyou | Apr 08, 2004 07:58pm | #12

   Good luck- let's see some pics when you're done.

3. 
   BMan | Apr 07, 2004 03:50pm | #6

   Greencu is right- Use flat seam methods for low slope roofing, not standing seam. If the roof is less than 1/2" per foot, the joints will have to be sweated full with solder. Depending on the size of the roof, expansion battens may have to be incorporated. Refer to the SMACNA handbook for details on how to do it right.

4. 
   RobKress | Apr 07, 2004 03:54pm | #7

   David,

   Have you seen the price of copper lately!!!  Was going to do a small porch section on my new house but it ended up being 1/2 the price of the rest of the shingled roof ($2500).  Too steep for me.  And I was getting a deal.

   Hope you get a better price,

   Rob Kress

1. 
   VaTom | Apr 08, 2004 06:36am | #8

   Have you seen the price of copper lately!!! 

   I have 2000 lbs due on Tuesday.  It's up to $2.13 here.  Right at 50% higher than a year ago.  Almost as large an increase as rebar.PAHS Designer/Builder- Bury it!