Simulated vs Cast Stone

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Author Message Anonymous   Posted on Wednesday, May 14, 2008 - 07:45 am:    What is the difference between Simulated Stone, i.e. Cultured Stone and Cast Stone? Dave Metzger Senior Member Username: davemetzger Post Number: 272 Registered: 07-2001 Posted on Wednesday, May 14, 2008 - 08:37 am:    Cast stone contains portland cement, sand, and water, and typically receives a fine sandblasted finish. In appearance and finish it is similar to cut dimension limestone. Cultured stone contains stone dust in a resin binder, and is meant to simulate marble. But it has the appearance and "feel" of solid surfacing material, not stone. Anonymous   Posted on Wednesday, May 14, 2008 - 08:45 am:    dave this is the Cultured Stone I refer to: http://www.culturedstone.com/ Colin Gilboy Senior Member Username: colin Post Number: 139 Registered: 09-2005 Posted on Wednesday, May 14, 2008 - 09:09 am:    Cast stone is a high density, high strength concrete, probably exceeding precast concrete in properties. It is a replacement for actual cut stone for copings and other areas. These are generally set with anchors and mortar. Cultured Stone (the original company name was Stucco Stone) is a much lower density material used as a veneer (generally residential) to simulate stone. These are also known as manufactured stone. They are adhered with a stucco type adhesive. There is an interesting trend of actual stone veneer replacing the manufactured stone. Dave Metzger Senior Member Username: davemetzger Post Number: 273 Registered: 07-2001 Posted on Wednesday, May 14, 2008 - 09:16 am:    "Simulated stone" is a better description of this product, even though Owens Corning calls it "cultured stone". I have had just one project where the architect wanted this product. Based on my research, I would be careful with using it near grade; I'd use true stone at such locations. We required the following submittals (among others): 1. Test data on physical properties including vapor permeance and porosity. 2. Simulated stone manufacturer's certification that simulated stone is appropriate for exterior use in building walls, and that simulated stone contains no expansive agents. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 903 Registered: 03-2002 Posted on Wednesday, May 14, 2008 - 10:00 am:    The product is not really described on the website. Whenever that's the case, my suspicions are raised--are they hiding something? Since it's owned by Owens Corning, makers of glass fiber products, and they refer to it as "composite," I'm assuming it is fiberglass-reinforced polyester--no stone or portland cement involved. Richard Howard, AIA CSI CCS LEED-AP Senior Member Username: rick_howard Post Number: 181 Registered: 07-2003 Posted on Wednesday, May 14, 2008 - 10:07 am:    We have a project recently completed with Cultured Stone veneer. We were required to use this material to satisfy the local controlling board for conformance with other buildings in the neighborhood. It is pretty realisitic looking. It is also less expensive and certainly as durable as our locally available rubble limestone would be if laid up as a veneer. But then our local limestone is best utilized for stone fencing or as gravel. You need to design a really good stucco installation with the appropriate weather barrier, flashing and drainage provisions. The Cultured Stone is then adhered in mortar over the base coats. Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 554 Registered: 05-2003 Posted on Wednesday, May 14, 2008 - 10:13 am:    Richard, did you apply a water repellent over the simulated veneer? Richard Howard, AIA CSI CCS LEED-AP Senior Member Username: rick_howard Post Number: 182 Registered: 07-2003 Posted on Wednesday, May 14, 2008 - 11:07 am:    Although OC does not object to a silane coating, no water repellent was used over the veneer. The installation is only at the east face of the building and there is a large overhang. Given the exposure, we were satisfied with the manufacturer's test data for freeze/thaw and our installation was not in a location prone to staining. I should add that this veneer was installed over cold-formed metal framing and glass-faced gypsum sheathing with a layer of Stucco Wrap. The stucco base coats were applied on self-furring galvanized lath. Our designers had wanted to use Citadel Thin Bed Building Stone by Arriscraft as the masonry veneer. Like other Arriscraft products, this calcium silicate "stone" is formed under high pressure without cement. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 904 Registered: 03-2002 Posted on Wednesday, May 14, 2008 - 11:50 am:    Richard, Was my posting correct that this product is FRP? Dale Roberts CSI, CDT Senior Member Username: dale_roberts_csi Post Number: 51 Registered: 10-2005 Posted on Wednesday, May 14, 2008 - 12:15 pm:    Cast Stone must meets ASTM 1364 it is a high strength low absorption product. Freeze thaw stable mainly used back east. Cast Stone is made from fine and coarse aggregates such as limestone, marble, calcite, granite, quartz, natural sands, Portland cement, mineral oxide coloring pigments, chemical admixtures and water. Check out www.caststone.org Simulated stone (at this time there is no ASTM they are working on one) is a lightweight concrete product, typically high absorption material used on the westcoast. Not a freeze thaw stable product due to its absorption rate which at this time they are not going to have any requirements in the current ASTM being proposed. Cultured Stone Falls into the Simulated Stone Category, Cultured Stone is a registered trade mark of Owens Corning. Some people use cultured stone like Kleenex even thought that was a registered trademark Dale Hurttgam, NCARB, AIA,LEED AP, CSI Senior Member Username: dwhurttgam Post Number: 32 Registered: 10-2005 Posted on Wednesday, May 14, 2008 - 01:03 pm:    We've had some problems with cast stone and try not to use it or to limit it's use to small areas as an accent. We do not apply the same restrictions to "wet cast". Our problems have included cracking when used as a lintel unit (we definetly no longer use it in any "structural" applications), chipping and quality control problems on units, discoloration and moisture problems. We definetly would not use it in coping applications. Richard Howard, AIA CSI CCS LEED-AP Senior Member Username: rick_howard Post Number: 183 Registered: 07-2003 Posted on Wednesday, May 14, 2008 - 01:51 pm:    John: Owens Corning "Cultured Stone" is a portland cement-based wet-cast product made with lightweight aggregate and iron-oxide pigments. I don't know if they use any glass fiber in it. John Regener, AIA, CCS, CCCA, CSI, SCIP Senior Member Username: john_regener Post Number: 392 Registered: 04-2002 Posted on Wednesday, May 14, 2008 - 02:47 pm:    Simulated stone, by several manufacturers, is used frequently on residential and commercial buildings and site walls in Southern California, Southern Nevada and Arizona. All the concerns about freeze-thaw are valid. In the southwest, it's not a problem except when the site is in snow country. Water repellent is advised to prevent spalling and delamination from the substrate due to freezing of absorbed water. It also helps in cleaning after the project is completed. This simulated stone is applied over a reinforced 1/2" portland cement plaster scratch coat. The "stone" units are set with special "veneer setting" portland cement mortar. See ICC Evaluation Service, Inc. Reports ER-3568 and ER-5403. There is no FRP involved. Brian E. Trimble, CDT Senior Member Username: brian_e_trimble_cdt Post Number: 16 Registered: 08-2005 Posted on Friday, May 16, 2008 - 03:11 pm:    I've been on some efflorescence complaints recently where brick and cast stone has been used. Efflorescence is all over the brick somewhat nearby to the cast stone. I am becoming concerned that efflorescing salts are coming from the cast stone. Are integral water repellents ALWAYS used in the cast stone, or SOMETIMES used in cast stone? Why am I seeing more of this now than in the past? David R. Combs, CSI, CCS, CCCA Senior Member Username: davidcombs Post Number: 277 Registered: 08-2004 Posted on Sunday, May 18, 2008 - 08:33 am:    Efflorescence is promulgated by water intrusion, and not necessarily because cast stone is present in the assembly. You may be seeing it more often because poor construction and wrong methodology have a way of repeating themselves project after preoject. First, what is the configuration of the wall? The most common I've seen, where efflorescence has developed, involves an exterior brick wall with a cast stone cap. If yours is a similar situation, then . . . 1. Is there flashing under the cast stone (to keep any water that may migrate into the stone from finding its way down into the brick)? Are there weeps to provide a conduit for the moisture to get out? There seems to be this prevailing falacy that - since cast stone is so dense - the flashing is either redundant or not necessary. If it present, are there assurances that it was installed properly? 2. Was mortar used to fill the head joints between the cast stone units? If so, this could be another source of water intrusion into the wall. In nearly every wall assembly of this type I've seen, the mortar almost always - and rather soon after construction - becomes separated from the cast stone. The head joint of horizontal surfaces like sills and wall caps should be filled with joint sealant, not mortar. If there is proper and suitable flashing below the cast stone, and the head joints are filled with joint sealant, you may want to look elsewhere for the source of the water intrusion.