Missed Opportunities in the Mirabella Wall Reconstruction Project
By Philip Wemhoff
Mr Wemhoff is a physicist with an advanced degree in business. He is a building researcher, a former consultant to the Florida Solar Energy Center, the State’s primary building research agency. He has been a state-licensed builder for 30 years, the manager of JEA’s new home construction program for 20 years, a visiting building science instructor at the University of North Florida, and the author of a book, cited here and here, and several papers on preventing construction mistakes like the ones described below.
Background
To All Mirabella Owners:
On April 04, 2022 your board, seeking to know of any missteps in the wall reconstruction project, posed four questions to building researcher, Philip Wemhoff. The questions are paraphrased here:
- What violations of the specifications and of ASTM C1063 and C926, if any, were missed by the Inspector?
- What corrective action is possible?
- On what date were alleged violations observed?
- Are professional engineers infallible, and can they learn from building scientists?
Introduction
For the ongoing wall reconstruction project this report focuses on missteps in the stucco cladding, not the wood framing repairs, because the stucco assembly contains the water control system – the key to preventing another expensive rotting of the wood framing. And, wood rot is the raison d’être of the reconstruction project.
It will be shown below that crucial Designer specifications were NOT enforced, which has ramifications for the upcoming roofing project. If the standards and specifications for expensive roofing installation are not strictly enforced, the association and its Owners may loose their roofing warranty, entirely. And, that means the Inspector must be on the roof DURING the work effort.
Specification & Code Violations
Typically, for such projects there are two sets of construction standards that MUST be met, one imposed by the Designer and the other imposed by the Florida Building Code. The local City building inspector enforces only the state code but has no role in assuring that the Designer’s specifications are implemented.
Designer Specifications. The Designer mandated specific features for the stucco assembly, called “specifications,” including the Code-required ASTM standards C926 and C1063. Some specifications were not installed or not achieved successfully.
And, the Designer failed to specify explicitly several highly-beneficial wood rot-prevention features such a Stucco Drainage Plane, a 10-20 perm Weather Resistive Barrier, and a high-perm finish coating (paint), features which are discussed in detail in this downloadable report from Mr Wemhoff.
This 2022 Fine Homebuilding article (Figure-1, Page-2, comes from that article) also provides great detail on the need for a Stucco Drainage Plane (an air-gap between stucco and wood framing). It also depicts desirable head flashings above windows. Google <stucco drainage plane>, and you will understand their value to rot-prevention.
However, those crucial features are not the subject of this paper. This current paper addresses only features which were unquestionably specified but not installed. It should be noted that so many important Designer specifications were ignored by the Inspector, that this author, Philip Wemhoff, assumed that the Designer did not supervise or inspect the installation.
Yet, the Designer did indeed inspect the work; he just didn’t think his specifications important enough to enforce. Nevertheless, he charged Owners for preparing specifications. Why charge Owners for specifications, if they are not going to be used?
1. Flashings. Although specified by the Designer, two types of flashings were not installed. They are shown in the Designer’s Specification Details 1-A1 and 2-A1, page 3. Instead of the compulsory horizontal flashings between floors (Detail 2-A1), plastic control joints were installed, plastic joints which, regrettably, will not drain the wall above.
The Result: Stormwater will be trapped within the stucco assembly where it will contribute to rotting. Between-floor flashings are needed, because water is not able to travel 10-30 to the bottom of the wall, near the foundation, to reach the Weep Screeds which assist drainage.
2. Stucco Finish Coat. The Designer specified a 1/8-inch thick “factory-prepared acrylic finish, texture as specified” for the finish coat. But, instead Portland Cement Plaster appears to have been installed as the third stucco coat.
This change may (or may not) be significant, because Portland Cement, combined with a high-permeance silicone coating, offers a better likelihood of water control than an acrylic finish. Unfortunately, it is NOT likely that such a high-permeance coating is being installed.
The Result: Stormwater within the stucco will not be able to dry to the outside so easily, increasing the risk of rotting.
3. ASTM C1063, mandated by the Designer and the Florida Building Code
- Section 7.11.4.2 “The distance between control joints shall not exceed 18 ft (5.5 m) in either direction or a length-to-width ratio of 2-1/2 to 1.” A tape measure will confirm excessive joint separation where it exists.
The Result: According to the literature, the absence or misplacement of control joints may increase the risk of stucco cracking and thus stormwater entry through resultant cracks.
- Section 7.11.5 Foundation Weep Screed — “Foundation weep screed[s] shall be installed at the bottom of all steel or wood framed exterior walls . . . The weather resistive barrier and lath shall entirely cover the vertical attachment flange and terminate at the top edge of the nose or ground flange.”
How this should be done is illustrated in Graphic-3 of this Wemhoff paper, and in this 2022 Fine Homebuilding article whose graphic is shown on Page-2. However, in all Mirabella installations, the Weather Resistive Barrier (WRB) does NOT “cover the vertical attachment flange” of the Weep Screed, that is, the WRB does NOT lap over the Weep Screed, the important wall drainage component which contains drainage holes.
The Result: The stucco assembly is prevented from draining properly, increasing the likelihood of wood rot. The problem is caused by a common scheduling error: Weep Screeds (like flashings) must be installed BEFORE the WRB is installed. But, the tradesmen who install the Weep Screeds arrive on the scene AFTER the tradesmen who install the WRB.
4. ASTM C926, mandated by the Designer and the Florida Building Code.
- ASTM C926, like C1063, also requires functional Weep Screeds. However, FUNCTIONAL Weep Screeds are not present in the Mirabella project: “A2.2.2 At the bottom of exterior walls . . .[there shall be installed] a drip screed and through-wall flashing or weep holes or other effective means to drain away any water that may get behind the plaster . . . ”
In addition, the lack of an effective Drainage Plane compounds the problem. Even if the Weep Screeds worked, stormwater won’t be delivered to them.
- Section A2.1.1 reminds us that “Plaster shall not, however, be considered to be waterproof.” Yet, in cases of wall penetrations, stucco is wrongly praised by the Inspector as a component of waterproofing. See Figure 2, copied from the report named 3-4-2022 Mirabella B-14 Update Report.pdf (page-7), and the report named Mirabella Bldg 2 Update Report 3-4-2022.pdf (page-5).
The Result: Stormwater will enter through such wall penetrations and cause wood rot. To manage wall penetrations correctly a flashing must be installed above each penetration and configured so that the Weather Resistive Barrier (WRB) laps over the vertical leg of the flashing. So, like Weep Screeds, flashings usually must be installed before the WRB is installed.
Prefabricated flashing kits work well for stucco wall penetrations, as affirmed by the National Association of Home Builders. These videos depict the installation of prefab flashings for plumbing penetrations, as well as for electrical cable penetrations and for air conditioning line penetrations.
- Section A2.1.2 imposes further requirements on penetrations, which C926 calls “openings”: “Flashing shall be specified at openings, perimeters, and terminations . . . ” Yet, flashings are missing above nearly all openings, including pipe and utility penetrations and windows.
Further, the Designer in his specifications mandates between-floor flashings. See Detail 2A1, page 3, of the specifications. Consistent with the Designer’s reasoning, windows should be equipped with head flashings, atop the windows, as shown in Graphic 6 of this document. Fine Homebuilding also describes the value of window head flashings as shown in this 2022 article, whose graphic is reproduced in Figure 1, Page-2.
Window mounting flanges will not function as head flashings. The flanges are open at the corners, and do not extend horizontally beyond the window, allowing water to rot wood at the sides of windows.
The Result: The Designer, in his construction reports, verifies the too frequent prevalence of wood rotting aside the windows, which can often be prevented by flashings.
And, of course, tape, used to bind housewrap to window frames and to form inadequate flashings, will not be binding after a few years of heat and stormwater. Figure 3 shows that the tape is already separating from the housewrap. And, aluminum undergoes a vigorous chemical reaction when exposed to Portland Cement.
- Section A2.2.3 Drip edge. “Where vertical and horizontal exterior plaster surfaces meet, both surfaces shall be terminated with casing beads with the vertical surface extending at least 1⁄4in. (6 mm) below the intersecting horizontal plastered surface, thus providing a drip edge.”
The Designer specified a detail similar to this requirement, although the accompanying text acknowledges that it omits the soffit/ceiling part of the detail. See Detail 1A3, page 4, of the wall specifications. Nevertheless, where there was an opportunity to achieve this requirement, it was not implemented.
The Result: Without a drip edge storm water will linger on the horizontal surface (the soffit/ceiling), increasing the probability that wood rot will occur in that location.
Explicit Commands
Too often the Designer in his specifications cites standards, like ASTM C926, in name only. But, that does not get the attention of the Installer who may have long forgotten some of the crucial or more complicated components of the standard. In our case both the Installer and Inspector forgot (or never knew) key elements of C926 and C1063 which are mandated by the Florida Building Code.
So, to serve his client better the Designer should include in his specifications the key text from the standard, as well as graphic illustrations.
The Designer’s roofing specifications are a case in point. After excluding text on permits, meetings, storage, cleanup and protection, there is scarce shingle and flashing detail and no illustrations. For example, an essential component, step flashing, is never mentioned and there are no illustrations. And, for the large number of cited standards there are no text excerpts to clarify the more complicated concepts.
Of course, there will be no advantage to text excerpts and graphics, if the Inspector is NOT going to enforce them, which has happened for some wall standards. And, the inspector will have to be on the roof during the installation, not after the work effort.
But, assessment of the roofing specifications is a task for another day.
How To Avoid Wasting Owner Wealth
Vast wall areas have been repaired, when restoration areas might have been much smaller, saving Owner funds. The paramount issue is: How does one determine which wall areas are rotting, when the exterior is covered by Portland Cement stucco?
The Designer’s approach is apparently to use observation ports cut into the stucco, which cost many hundreds of dollars for each port – requiring stucco cutting, demolition, reinstallation and painting.
The process is so costly and disruptive that only a few ports are opened, making it difficult to MAP accurately the pattern and extent of the rotting. As a result some walls may be fully disassembled and replaced needlessly.
However, high-quality instruments (see Figure 4) can map the rotted zone accurately from inside the building, through the gypsum wall board. Few outside tests are needed. Each indoor test site endures only two small 1/8-inch holes which are easily caulked and painted – for a total cost of about $20 each.
Thus, scores of samples can be taken from indoors, at the cost of one outside observation port, allowing for a more accurate mapping of the rotted zone. So, truly rotted areas will be identified, and undamaged areas will be spared costly and wasteful reconstruction.
Is the Designer Infallible?
People, who don’t know anything, too often seek out “experts” rather than undertake even a rudimentary self-education. It shows in the board’s obsession with professional engineers. Contractors love to take advantage of uninformed boards and managers, to the detriment of hundreds of property owners.
Professional engineers, like board members, make mistakes. All professions, whether physician, attorney or carpenter, contain practitioners that are more skilled and more competent than other practitioners.
For example, no engineer possesses the identical competence, talent and imagination of all other engineers – otherwise the word “talent” has no meaning. One engineer could have vastly superior talent in some practice areas as well as weaknesses in other areas.
And, every professional learns as time progresses. That’s why we don’t want to be the first patient under a new surgeon’s knife. In the current case, for example, the author suspects that the Designer, in all future stucco-frame projects, will explicitly stipulate a Drainage Plane (and other key features) in his specifications. He has learned something new and will want to reduce future liability.
An exceptional way to avoid professional mistakes is to have a peer, preferably an independent superior, review one’s work and recommendations, which is the practice used by Mr Wemhoff in this case. As a result, the content of his project commentary (downloadable here) was reviewed by the nation’s leading building scientist and construction pathologist, Joseph Lstibrek (pronounced STEE-BRICK).
Violations First Observed
Missteps were first observed at Building 14 in early December 2021. The author, Philip Wemhoff, made immediate contact with the board using email – when that failed to get a response, using USPS letters. The board response was hostility, perhaps fearing that it would be blamed for the problems.
Even at the December 15, 2021 association meeting Mr Wemhoff was not allowed to speak, which is a violation of Florida Statutes 718.112 (2)(c). On December 15 Mr Wemhoff repeatedly explained the urgency and the need to educate the board and Owners on what was happening, stating that, unless corrective actions were taken immediately, proper Stucco Drainage Planes could never be installed in Building 14 or the other buildings undergoing wall repairs.
There was plenty of meeting time; there was no other business to conduct. Yet, the board silenced Mr Wemhoff, violating its fiduciary obligations to Owners, as mandated by Florida Statutes.
In late December the board’s hostility continued – it spent $3,000 of Owner’s money to pay an attorney to warn Mr Wemhoff against questioning the faulty wisdom of board members – an improper use of Owner wealth in order to maintain a coverup.
And, although the Designer, a Jeffery Sellers, wanted to speak with Mr Wemhoff, the board instructed him to not to communicate with Mr Wemhoff. Notably, the board promised such a Wemhoff-Sellers conversation during the December 15 meeting. However, once Owners were no long present, the board changed its mind – to its great dishonor.
At the subsequent association meeting, March 29, a new 3-minute rule was established to curb Mr Wemhoff’s speech. And, he was the only Owner timed by a clock in order to prevent other Owners from learning of the board’s mistakes.
It is the board’s disgrace that, had it acted wisely and fiducially in December, all the repaired buildings might have been equipped with the best rot-prevention technology available. Simply by allowing itself to become educated, the board could have reduced the probability that walls will have to be replaced AGAIN at a waste of Owners’ wealth. That education is a fiducial obligation demanded of the board by Florida Statutes.