kurt Posted December 11, 2011 Report Posted December 11, 2011 We've got a couple repair gigs going now.....a copper cornice, and a venting masonry coping system for a really wet double wythe wall. Nice materials.......we had it custom fabricated to approximate near as we could the original cornice. These are some of the parts..... Click to Enlarge 94.42?KB Click to Enlarge 93.01?KB Click to Enlarge 98.23 KB We fabricated these stainless brackets; they fasten to the wall, the copper mounts to the bracket. That's only after we rebuilt the wall from the 2nd fl. windows up. Click to Enlarge 54.86?KB I think it'll look good. Click to Enlarge 98.74 KB
Jim Katen Posted December 11, 2011 Report Posted December 11, 2011 Looks nice and expensive. What are the details on the new coping system?
Bill Kibbel Posted December 11, 2011 Report Posted December 11, 2011 Very, very nice copper work. Who did the work? Was the original cornice copper?
Chad Fabry Posted December 11, 2011 Report Posted December 11, 2011 That's beautiful. The copper work is truly awesome.
Marc Posted December 11, 2011 Report Posted December 11, 2011 Beats anything I've ever seen in copper. Still trying to figure how the craftsman could do it. Marc
randynavarro Posted December 11, 2011 Report Posted December 11, 2011 Looks cold there! Yes, I'm also curious how they fabricated those pieces. All I keep thinking is the same type of extrusion machine they use to roll out continuous aluminum gutters.
mgbinspect Posted December 11, 2011 Report Posted December 11, 2011 Nice looking work! When I first arrived in Richmond, there used to be a lot of lovely copper work here, but it seems no one can afford to replace ir renovate it. I see less of it as time goes on. I suppose, as soft as copper is, it's fairly easy, with the right tools, to press it against forms into just about any shape. I remember, when I was a kid, you could get sheet copper and a mould to form your own little copper relief, which you then stained an d wiped down to give it all depth. They were pretty popular in hobby shops back then. [:-propell
kurt Posted December 11, 2011 Author Report Posted December 11, 2011 A local sheet metal company did the work. Man, the world has changed with CNC equipment. We all sat there pulling and pushing on lines in AutoCad, extend the ogees, tweaked the fluting (or whatever you call it), extended the panels, etc., etc., and when we had the profiles the size and proportion we wanted them, hit a button and the stuff rolls out of the machinery in the back room. For someone that remembers obtaining custom step flashing being a big deal, being able to run out any profile of anything in any material is still mind boggling. Even after the profiles were run, it was still a lot of soldering and fabrication. The copper and brackets, not installed, hit somewhere around $18,575..........woof...... We're on scaffolding now, installing brackets. I'll put up a couple more pics when we're mid process. Here's the vented coping details.......we invented it and are fine tuning things. We've already figured out a better way for just about everything, but you know how things go......you gotta start before you can see everything...... We start with brillo pad ridge vent material wrapped in a spunbond propylene cloth; very high vapor permeability, low perm water permeability. Click to Enlarge 78.04?KB That gets capped with metal profile secured to plastic blocking previously installed with the brillo pad. Click to Enlarge 81.13?KB Then the 40 mil self adhered to the metal. Click to Enlarge 47.93?KB This is an end view of the venting arrangement. Click to Enlarge 51.2?KB Another view of the vent reveal. Click to Enlarge 43.17?KB The limestone (client wanted to keep limestone) secures to the metal with pins and masonry adhesive. The load is bearing on the plastic blocking under the metal. We'd have preferred to ditch the stones. We've got a couple profiles figured out with sheet metal that would be a lot better with more air space. We've got some customers that are going to go with metal coping; I'll put up the pics when we get on that job. We got it all assembled and in place, then the cold spell hit. In the morning, you can see steam coming out of the venting area. I think it's gonna work.
Jim Baird Posted December 12, 2011 Report Posted December 12, 2011 Great stuff. Somebody among the "we" has some good design sense.
kurt Posted December 12, 2011 Author Report Posted December 12, 2011 Thanx. We're kinda proud of it. Even our mason, historically circumspect about pretty much everything and as conservative as it gets, said "is ok" and (kind of) smiled. We've got improvements to every component for the next one. It's a work in progress, but thanks.
Tom Raymond Posted December 12, 2011 Report Posted December 12, 2011 Drip edges would be a good idea. And a bit of slope on the coping (toward the roof) couldn't hurt either. Keep the wall dry and it'll need less venting. The copper is gorgeous.
Richard Moore Posted December 12, 2011 Report Posted December 12, 2011 A local sheet metal company did the work. Man, the world has changed with CNC equipment. We all sat there pulling and pushing on lines in AutoCad, extend the ogees, tweaked the fluting (or whatever you call it), extended the panels, etc., etc., and when we had the profiles the size and proportion we wanted them, hit a button and the stuff rolls out of the machinery in the back room. For someone that remembers obtaining custom step flashing being a big deal, being able to run out any profile of anything in any material is still mind boggling. Even after the profiles were run, it was still a lot of soldering and fabrication. The copper and brackets, not installed, hit somewhere around $18,575..........woof...... etc... I'm having trouble picturing "sheet metal" CNC equipment that could produce all those details. Are some of the intricate bits milled out of billet? Nice to have a client that doesn't balk at price. Commercial property?
kurt Posted December 12, 2011 Author Report Posted December 12, 2011 Drip edges would be a good idea. And a bit of slope on the coping (toward the roof) couldn't hurt either. Keep the wall dry and it'll need less venting. The copper is gorgeous. The sheet metal all stands off the masonry minimum 1/2", with a "drip groove" formed by the ventilation space. That's a drip edge. The stone has a slight pitch to it; it drains. Keeping the masonry dry? All we can do is siloxane. Rebuilding to clear the cavity and get all the flashing right would've been about $225,000. The guy wants his building fixed, not rebuilt. I think we did OK.
kurt Posted December 12, 2011 Author Report Posted December 12, 2011 I'm having trouble picturing "sheet metal" CNC equipment that could produce all those details. Are some of the intricate bits milled out of billet? Nice to have a client that doesn't balk at price. Commercial property? Nope. Single family residence in Lincoln Park, land of hedge fund managers, corporate attorneys, and McKinsey consultants. The machinery would blow your mind. Put it all on screen, 3D model it, break it down into parts, push and pull a few dimensions and the changes radiate throughout the entire cornice, feed the metal, and magic comes out the other end. Like I said, I remember when just getting some decent copper angles for step flashing with a simple contour for counter flashing was a big deal that took weeks. We can go in with a simple profile, and walk out a half hour later with product to install. This project took a while longer, but it was still pretty darn quick. The original cornice was painted metal. It had rusted out to nothing and was held together with pop rivets, coil stock, and roofing cement. The owner wanted something "cool". We gave them cool.
Tom Raymond Posted December 12, 2011 Report Posted December 12, 2011 I wasn't putting down your design, merely offering suggestions for version 2.0. You did say there were things you'd improve upon for the next one. If it's less than 50 years old, it doesn't have near enough drip edges. Drip edges on your coping, and on any every other horizontal projection will minimize the amount of water the wall is exposed to. Buildings get wettest at their edges. An amazing amount of air moves through the wythe space, employing it to dry out a wet wall is smart. How do you plan on monitoring the performance?
Marc Posted December 12, 2011 Report Posted December 12, 2011 An amazing amount of air moves through the wythe space, employing it to dry out a wet wall is smart. That would seem to imply that air currents enter, navigate then leave the wall cavity. So how does this air flow enter the walls in the first place? I thought only vapor drive was involved. Marc
kurt Posted December 14, 2011 Author Report Posted December 14, 2011 We've been measuring the moisture content in the bearing points of the top chord bearing truss. We made our own extra long deep probes; we can measure in about 18". Take off base shoe, drill pilot hole at long angle to get into the truss. There's stack effect in these places...air enters around electrical outlets or any other penetration. We're air sealing as much as feasible, and counting on the free air space to allow moisture to equalize out of the cavity. There'll still be stack effect to help evaporate moisture.
Tom Raymond Posted December 14, 2011 Report Posted December 14, 2011 It's new enough for trusses, that explains a lot. How long has the monitoring been going on and are you getting any results?
kurt Posted December 14, 2011 Author Report Posted December 14, 2011 10 year old house.......exactly. They all leak. All of them. I am increasingly convinced the increase of leakers is directly related to the corresponding decrease in soft lime mortars. Flashing is only part of the deal. We're too soon into it to have reliable numbers. We'll know something next spring after we go through the winter drying cycle.
Marc Posted December 14, 2011 Report Posted December 14, 2011 10 year old house.......exactly. They all leak. All of them. I am increasingly convinced the increase of leakers is directly related to the corresponding decrease in soft lime mortars... Meaning that the particular bricks used on the outside don't have much permeability? Marc
kurt Posted December 14, 2011 Author Report Posted December 14, 2011 No, it's about the micro-fissures, occurring primarily in the mortar joint, that create capillarity. The autogenous healing of all these fissures is the miracle of lime mortar. All these highly vitrified bricks and hard brittle mortars are the problem. Assemblies that are essentially fractured marbles relying on flashing for water management is backward thinking. Sounds modern and smart on the front end, but it falls down badly in the performance end. The degree of meticulousness necessary to get all the flashing right runs counter to masonry practice.....masonry is a tough gig, nothing harder, and getting the flashing right is expecting a lot of guys with club hands and a hard gig to perform something akin to needlepoint. Soft mortar. Forget what the engineers say about compressive strength and high psi mixes........use soft lime rich mortar if you want the wall to work.
mgbinspect Posted December 15, 2011 Report Posted December 15, 2011 No, it's about the micro-fissures, occurring primarily in the mortar joint, that create capillarity. The autogenous healing of all these fissures is the miracle of lime mortar. All these highly vitrified bricks and hard brittle mortars are the problem. Assemblies that are essentially fractured marbles relying on flashing for water management is backward thinking. Sounds modern and smart on the front end, but it falls down badly in the performance end. The degree of meticulousness necessary to get all the flashing right runs counter to masonry practice.....masonry is a tough gig, nothing harder, and getting the flashing right is expecting a lot of guys with club hands and a hard gig to perform something akin to needlepoint. Soft mortar. Forget what the engineers say about compressive strength and high psi mixes........use soft lime rich mortar if you want the wall to work. [^]
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