Darren Posted March 25, 2011 Report Posted March 25, 2011 I just attended a seminar on 'Stucco Applications' present by Frank Hendron Building Science Consultant & Co-Chairman of ASTM C-1063 (this standard is written into the code R703.6) He stated the application of stone veneer is to be treated as stucco. One of the mock-ups he had included exactly what Jim's photo shows with one exception. R703.6.3 state 2 layers of water resistive barrier is required. His mock-up showed Tyvek against the sheathing and then Grade D building paper is which the mesh & plaster 'adhere' (if no mesh were present). He called the building paper sacrificial since it gets damaged during the plaster process. Here is the most important detail most everyone misses. The drainage plane needs flashing at the sill plate that rests on the foundation wall. R703.7.5 Flashing- Flashing shall be located beneath the first course of masonry above the finish ground level above the foundation wall or slab and at other points of support, including structural floors, shelf angles and lintels when masonry veneers are designed in accordance with section 703.7. ASTM C-1063 7.11.5 Foundation weep screed shall be installed at the bottom of all steel and wood framed walls to receive lath and plaster. Screed shall be not less than 4inches above raw earth and 2 inches above paved surfaces (roof is considered a paved surface) The weather resistive barrier and the lath shall entirely cover the vertical attachment flange and terminates at the top edge of the nose or ground flange.
hausdok Posted March 25, 2011 Report Posted March 25, 2011 Hi All, I'd completely forgotten about this post. Ironically, the Masonry Veneer Manufacturer's Association released its first best practices guide just a couple of months before Jim's initial post. They've since updated it - in June 2009 - I think. Many of the preferences that Jim had in his first few posts above have been incorporated into this guide. You can read and download a web version complete with drawings here. ONE TEAM - ONE FIGHT!!! Mike
mark parlee Posted March 29, 2011 Report Posted March 29, 2011 Thanks Mike. The details are important as this system is, by some estimates, capable of storing ten times the moisture that an EIF system can. I wrote the article on stone that appeared in the Dec 08 issue of the JLC on rescuing a manufactured-stone wall. This followed all of the current procedures of the time from the Cultured stone installation manual that Certainteed had published. Very little difference in the current MVMA guidelines. I now specify a rainscreen type mater to be used and we have absolutely no problems as we have given a clear channel for incidental moisture to drain. It is a wonder what this detail has done making this stone a barrier type system no longer. I have consulted on five stone jobs in the last two years where the moisture has intruded so severely to where it is considered to a complete wall failure. Since the article I have directly consulted on 7 of these failures and indirectly on 8 around the country. we do have problems and I have believe the stone problem will make the EIFS problem to look like a tiny drop in the bucket.
Marc Posted March 29, 2011 Report Posted March 29, 2011 Thanks Mike. The details are important as this system is, by some estimates, capable of storing ten times the moisture that an EIF system can. I wrote the article on stone that appeared in the Dec 08 issue of the JLC on rescuing a manufactured-stone wall. This followed all of the current procedures of the time from the Cultured stone installation manual that Certainteed had published. Very little difference in the current MVMA guidelines. I now specify a rainscreen type mater to be used and we have absolutely no problems as we have given a clear channel for incidental moisture to drain. It is a wonder what this detail has done making this stone a barrier type system no longer. I have consulted on five stone jobs in the last two years where the moisture has intruded so severely to where it is considered to a complete wall failure. Since the article I have directly consulted on 7 of these failures and indirectly on 8 around the country. we do have problems and I have believe the stone problem will make the EIFS problem to look like a tiny drop in the bucket. On page 4 of the MVMA (Summary Table), the manual specifies, for sheathed stud application, various combinations of 2 layers of WRB. The phase 'drainage plane' isn't there but then the use of 2 layers of WRB is the equivalent of a drainage plane, would this be correct? Or does this manual not recommend a drainage plane? Marc
mark parlee Posted March 29, 2011 Report Posted March 29, 2011 Marc The various specs try to cover every scenario. Without a drain plan this assembly can be very unforgiving over time and some of the problem I see have developed in a short amount of time. I have looked at three in the last six months that were less than a year old. As was pointed out in an earlier post this stone assembly is basically a stucco with rocks in the surface. I do not see many that use the weep screeds or casing beads. Generally it has the WRB over the sheathing, the wire mesh, and the faux stone. This is all applied in a hurried manner without regard to some of the finer detail required to make the assembly drain. I don't care how many layer of paper you put on if the assembly fills up the liner will eventually leak. on the repairs I have been involved it goes this way. Wall sheathing, WRB, layer of grade D, metal accessories, Delta dry or MTI, metal lath, scratch coat, rocks. This allows any incidental moisture to have a clear path to drain. Page 6 MVMA left side last paragraph: Rainscreen Drainage Plane Systems (Optional), should be mandatory. Delta Dry http://www.cosella-dorken.com/bvf-ca-en ... ts/dry.php MTI http://www.mtidry.com/
Darren Posted March 29, 2011 Report Posted March 29, 2011 I think figure 5 on page 14 is the most critical. If you don't let the moisture out at the base of the framed wall, then your just asking for trouble. I have a new house going up about a 1/2 mile from my house; talk about somebody not knowing what to do. I'll shoot by today and take some pictures.
hausdok Posted March 29, 2011 Report Posted March 29, 2011 I see the stuff almost daily and literally cut and paste comments from one report to the next and then just swap out the photos. As Mark said, no weep screeds and separation from concrete or grade, no casing beads or separation from woodwork. I've noticed a few times where some of these guys have over the past year or so begun to change their procedures; possibly at the behest of the builder or because they'd finally gotten a copy of the MVMA guidelines. I figure it will only take one major lawsuit involving a big development with dozens of homes done wrong for it to hit the news as a class action. When that happens, I bet the installers will get religion really fast and begun studying the crap out of those guidelines. ONE TEAM - ONE FIGHT!!! Mike
Darren Posted March 29, 2011 Report Posted March 29, 2011 At the seminar presented by Frank Hendron, he stated over the past several years he has done destructive investigation on homes here on the east coast for people willing to participate in his survey; out of 900 homes, 898 were incorrectly installed. Here's the house near me- Click to Enlarge 69.95 KB Click to Enlarge 63.28 KB Click to Enlarge 48.99 KB Click to Enlarge 57.46 KB Click to Enlarge 55.4 KB Click to Enlarge 46.25 KB Click to Enlarge 64.28 KB Click to Enlarge 54.62 KB
Rocon Posted April 5, 2011 Report Posted April 5, 2011 Click to Enlarge 43.92 KB Alot of new projects have sprung up in Reno with one coat plaster systems. No one seems to know how to detail them properly.
Marc Posted April 5, 2011 Report Posted April 5, 2011 Click to Enlarge 43.92 KB Alot of new projects have sprung up in Reno with one coat plaster systems. No one seems to know how to detail them properly. The funny thing about OCS (one coat stucco) is that it isn't just one coat...scratch coat, brown coat then textured finish. Marc
mark parlee Posted April 5, 2011 Report Posted April 5, 2011 Click to Enlarge 43.92 KB Alot of new projects have sprung up in Reno with one coat plaster systems. No one seems to know how to detail them properly. They do not detail them properly because it costs more and there is training and understanding required. This raises the price and they may not get the work.
Denray Posted April 5, 2011 Report Posted April 5, 2011 Click to Enlarge 77.95 KB I was riding my bike around town when I spotted this REO. Lots of stucco problems. Click to Enlarge 21.84 KB
Denray Posted April 5, 2011 Report Posted April 5, 2011 Click to Enlarge 38.31 KB Click to Enlarge 39.43 KB
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now