Basalt Exterior Wall Cladding

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Author Message Lisa Goodwin Robbins, RA, CCS, LEED ap Senior Member Username: lgoodrob Post Number: 268 Registered: 08-2004 Posted on Thursday, April 23, 2015 - 11:11 am:    Last minute design change! Architect wants to use basalt dimension stone cladding in lieu of slate, at building exterior in Massachusetts. I don't know much about the properties of basalt. What type of setting mortar is recommended for basalt? What are the safety factors for basalt? I've asked the Architect for more information and suggested they contact their Structural Engineer. Has someone else done this? Of course it's going to (public) bid tomorrow. - ken hercenberg Senior Member Username: khercenberg Post Number: 895 Registered: 12-2006 Posted on Thursday, April 23, 2015 - 11:46 am:    Never used it but it is igneous and presumably suitable for use as dimension stone. I'd require preconstruction testing since this can come from anywhere on Earth. I don't know what its tendency is to fracture or if different areas of supply test out differently. I presume you're using MasterSpec (or at least referring to it) even though the testing in the stone Section is pretty light. I would expect basalt to test out comparable to granite but that's pure conjecture on my part. I find it interesting that ASTM C119 says that it considers basalt as black granite. Still I would test modulus of rupture, compressive strength, etc. or at least require recent test reports for the specific vein that the stone is being quarried from. From what little I can remember from college, I thought basalt could have high iron content which means it might bloom on your building, again depending on what part of the planet you obtain the stone from. Might we worth testing for that as well. Lynn Javoroski FCSI CCS LEED® AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 1999 Registered: 07-2002 Posted on Thursday, April 23, 2015 - 12:05 pm:    Not sure this will be much help, but it's interesting: http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry27.html Seems to indicate that basalt might be heavier than granite which might effect the supports / installation. I'd start by contacting the supplier, assuming the Architect has one, and ask them for assistance. Lisa Goodwin Robbins, RA, CCS, LEED ap Senior Member Username: lgoodrob Post Number: 269 Registered: 08-2004 Posted on Thursday, April 23, 2015 - 01:05 pm:    Thank you both very much! Apparently I don't remember much of my college geology classes. Robert E. Woodburn, AIA, CSI, CCS, CCCA Senior Member Username: bob_woodburn Post Number: 163 Registered: 11-2010 Posted on Thursday, April 23, 2015 - 02:59 pm:    As Ken mentioned, commercially (though not geologically), it IS a type of granite. This from the web (lost the link): "For dark igneous rocks too fine grained to be termed “black granite”, the commercial names basalt and traprock...are used." For commercial purposes, basalt, and over a dozen other varieties of igneous rock, are considered granite, like "black granite," so popular for countertops. As I understand it, geologically, no "black granite" is a true granite (which typically includes some white mineral crystals), but is actually a type of gabbro. Why would one need to specify basalt any differently from any other "granite"? If testing, etc is required to verify the properties of granite, then the same would apply, and the same installation methods and materials would as well. Robert E. Woodburn, AIA, CSI, CCS, CCCA Senior Member Username: bob_woodburn Post Number: 164 Registered: 11-2010 Posted on Thursday, April 23, 2015 - 03:02 pm:    (Here's the link: http://www.aulavirtual.aidico.es/materialava/cd%20terminado/version%20digital/GLOBAL%20STONE%20CONGRESS%202010.%20FULL%20PAPERS/SESSION%205%20CHARACTERIZATION%20AND%20NEW%20PRODUCTS/S5-12.pdf ) anon (Unregistered Guest) Unregistered guest Posted on Thursday, April 23, 2015 - 03:12 pm:    This issue came up for me as well on a recent project. Through the miracle of Google I found this article: https://www.linkedin.com/pulse/20141018124954-22753229-chinese-basalt-g684-user-beware And learned quite a bit about this imported "basalt". I was also fortunate to have a dialogue with the author about my specific project after reaching out to him via email. If this is the same stone you are considering, you could do what I did, and require performance to be at least that of granite. If you need more info, I recommend getting in touch with Dr. Hans. He's very knowledgeable and helpful. Dale Roberts CSI, CCPR, CTC, LEED Green Associate Senior Member Username: dale_roberts_csi Post Number: 122 Registered: 10-2005 Posted on Thursday, April 23, 2015 - 09:16 pm:    In a freeze thaw area like Massachusetts, Basalt is a better option than slate for an exterior cladding.in the 2012 IBC code you can direct adhere, “1405.10.2 Exterior adhered masonry veneers—porcelain tile. Adhered units shall not exceed 5/8 inch (15.8 mm) thickness and a maximum of 24 inches (610 mm) in any face dimension nor more than 3 square feet (0.28 m2) in total face area and shall not weigh more than 9 pounds psf (0.43 kN/m2). Porcelain tile shall be adhered to an approved backing system.” Anything over that size needs to be mechanically attached. If you would like specific product recommendations for direct adhered installation systems please email me directly Thanks Lisa Goodwin Robbins, RA, CCS, LEED ap Senior Member Username: lgoodrob Post Number: 270 Registered: 08-2004 Posted on Friday, April 24, 2015 - 09:40 am:    Thanks so much for everyone's responses. The project's structural engineer also said to treat the basalt like granite. I have no idea where the design architect found this stone, or what will be purchased by the contractor (public bidding). The panels are too large for adhesive applications, which makes me nervous in NE anyway. Out to bid today! Thanks again. - Greta Eckhardt Advanced Member Username: gretaeckhardt Post Number: 5 Registered: 08-2013 Posted on Friday, April 24, 2015 - 10:32 am:    I would be very careful about using basalt as if it were granite. It has more iron in it and may cause staining, some of the minerals are not very stable in Earth's atmosphere, and its physical properties are likely to be different from standard granite. True basalt is also at least 10-20% denser than true granite, and the supports must take this into account. Of course the material that the supplier is calling basalt may really be something else geologically. At any rate, if it is being used in large panels for building cladding, the specific material must be tested for all the relevant performance properties, including those related to weathering and strength - I would call for preconstruction testing if reliable test reports are not available from the supplier. Michael Chusid Senior Member Username: michael_chusid Post Number: 22 Registered: 10-2003 Posted on Friday, April 24, 2015 - 10:46 am:    Basalt is black. Check out solar absorption and thermal expansion. Some basalt is formed into naturally hexagonal columns. It would be fun to build with those. Michael Chusid, RA FCSI CCS www.chusid.com www.buildingproduct.guru Robert E. Woodburn, AIA, CSI, CCS, CCCA Senior Member Username: bob_woodburn Post Number: 165 Registered: 11-2010 Posted on Friday, April 24, 2015 - 10:56 am:    Keep in mind that, as mentioned above, granite as commonly understood in the US is a commercial class including 20 or more geologically different classifications of igneous rocks, many if not most of which are not true granites (including gabbro, for exaple, which itself is a category). There may really be no such thing (commercially) as "standard granite" or "true basalt." Since even the same rock from different places in the quarry (or even different blocks) may have different characteristics, testing is always advisable, but is still not assurance that all the material furnished will be equal to or better than the sample. Greta Eckhardt Senior Member Username: gretaeckhardt Post Number: 6 Registered: 08-2013 Posted on Monday, April 27, 2015 - 09:53 am:    Agreed - preconstruction testing of samples from the exact location where the project slabs will be cut is critical. When I say "true basalt" I mean geologically classified basalt, which is an iron- and magnesioum-rich volcanic rock, formed by lava that cools quickly into a very small crystals and a glassy matrix. Since it is deposited in a flow it may have laminar features that could lead to delamination as the rock weathers. The hexagonal columns are the result of shrinkage cracking during rapid cooling of a thick flow. I think there may be good reasons that basalt has not been used historically in large slabs on buildings. In Minnesota and elsewhere it is referred to trap rock, and crushed for use as aggregate. Occasionally you will see basalt rocks used in a quaint, one-story stone masonry building in a state park.