December 19, 2013 Rev. Taylor Moore St. Peter's Episcopal Church 113 South Ninth Street
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December 19, 2013 Rev. Taylor Moore St. Peter’s Episcopal Church 113 South Ninth Street Oxford, MS 38655 RE: St. Peter’s Episcopal Church Architectural Assessment of Sanctuary Building Dear Vestry and Members of St’ Peter’s: Enclosed is the final report from Wiss, Janney, Elster Associates, Inc. regarding moisture problems in the sanctuary of St. Peter’s Episcopal Church. Styled as an “Exterior Masonry Investigation,” Steve Kelley also inspected masonry interiors, particularly in the crawlspace and in the belfry to reach conclusions about the sources of moisture intrusion and to recommend solutions. We believe this report provides a first step toward the long-term management of those issues. You should find encouragement that Steve gives the building a “clean bill of health,” for the most part. The problems we observed and that he identified in his report are problems with which you are already familiar. We are confident we have identified the full extent of those problems and their underlying causes. Taking a Hippocratic approach to your building – “first, do no harm” – will serve us best, so our recommendation is that we think of this as “managing” rather than “correcting” the problems. This document includes the following: • WJE’s final report, including illustrative figures and charts. • An initial budget estimate, revised from the one presented to the Vestry on December 9, to includes additional masonry restoration in the crawl space and in the belfry interior – re-pointing and re-parging. • A description of electro-osmosis systems and how they might work in this proposed application. Note that we stop short of recommending any electro-osmosis implementation. As I discussed with the Vestry on December 9, I add to, elaborate on, and establish priority among Steve Kelley’s recommendations in the following ways: First, implement the relatively easy and immediately effective tactics: • Currently, the existing downspouts on the building’s north side drain onto splash-blocks at grade, and from there into the well-developed swale that drains to the east. These downspouts should flow directly into a hard-piped, below-grade, storm-water drainage system tied to existing drainage inlet structures. This pipe can be installed in the same trench as the French drain system (which is the next item). • Install a French drain system near, but not below the foundation bearing elevation on the north, east, and west walls of the building, including around the base of the belfry. This Post Office Box 1569 • Oxford, Mississippi 38655 662.234.7444 • Fax 662.234.0008 www.howortharch.com should drain water from immediately below grade and rising groundwater, to reduce the amount of water available to wick up into the wall systems. The French drain will include a perforated pipe, gravel fill, and filtering fabric to keep fine soils and sand out of the gravel and pipe. It can tie into the same site drainage structures as the hard drainage pipe, but the perforated pipe and hard pipe should be separate so as not to introduce free water from hard pipe into the perforated pipe. • (Note regarding the two items above: We have not identified a readily accessible drain inlet near the back of the church. The existing swale on the north side of the church drains to a concrete flume and from there onto the parking lot. This is shallow with very little fall, so the run to a sub-grade storm drain may be some distance away.) • Disuse and remove or abandon sprinkler systems on the building side of the French drain system. Reduce watering as much as possible to ensure that whatever surplus water is introduced into the area can be drained by the French drain system. • Remove organic mulch from around the building and replace it, if you like, with a different soil cover that does not retain moisture in the soil. The next tier of tactics will require more care and investment: • Replace the roof and reflash the castellated parapets at the base of the steeple. • Begin a program of repointing mortar as indicated in the report, with duration to be completed within five years. Proceed in the following sequence of priority: o Begin with the belfry exterior. Note: repointing the top of the belfry can share scaffolding and/or lift expense with the roof work, so their schedule should be coordinated. o Second priority is the north wall. o Third priority is the east and west walls. o Fourth priority is the interior of the belfry, and finally the interior of the basement crawl space. • As the repointing begins, provided you have developed confidence in your restoration masonry restoration contractor, I recommend experimenting with removal of Portland cement parging, first on a limited basis and only with aggressive enough tactics to preserve the original building fabric – particularly the bricks – beneath the parging. Proceed only as aggressively as feasible without damaging the underlying material. While this report completes the scope of our current agreement, feel free to contact me for further assistance or advice or if you have any questions. Thank you for your confidence in Howorth & Associates Architects. Sincerely yours, Thomas S. Howorth, FAIA, President ST. PETER'S EPISCOPAL CHURCH Exterior Masonry Investigation Oxford, Mississippi Final Report December 13, 2013 WJE No. 2012.2232 Prepared for: Howorth & Associates Architects PO Box 1569 Oxford, Mississippi 38655 Prepared by: Wiss, Janney, Elstner Associates, Inc. 10 South LaSalle Street, Suite 2600 Chicago, Illinois 60603 312.372.0555 tel | 312.372.0873 fax ST. PETER'S EPISCOPAL CHURCH Exterior Masonry Investigation Oxford, Mississippi Stephen J. Kelley Principal Final Report December 13, 2013 WJE No. 2012.2232 Prepared for: Howorth & Associates Architects PO Box 1569 Oxford, Mississippi 38655 Prepared by: Wiss, Janney, Elstner Associates, Inc. 10 South LaSalle Street, Suite 2600 Chicago, Illinois 60603 312.372.0555 tel | 312.372.0873 fax TABLE OF CONTENTS Introduction ................................................................................................................................................... 1 Building Description and Construction History ............................................................................................ 1 References .............................................................................................................................................. 2 Methodology ................................................................................................................................................. 3 Visual inspection ........................................................................................................................................... 3 RILEM Tube testing ..................................................................................................................................... 6 Electrical Resistance Testing ........................................................................................................................ 9 Laboratory Testing ...................................................................................................................................... 10 Petrographic Analysis of Brick ............................................................................................................ 10 Absorption Tests of Brick .................................................................................................................... 10 Original Mortar ..................................................................................................................................... 11 Parge and Mortar Studies ..................................................................................................................... 13 Buttress Parge ....................................................................................................................................... 13 Under Parge .......................................................................................................................................... 14 Conclusions and Recommendations ..................................................................................................... 14 Appendix A ST. PETER'S EPISCOPAL CHURCH Exterior Masonry Investigation Oxford, Mississippi INTRODUCTION In accordance with the request of Howorth & Associates Architects, Wiss, Janney, Elstner Associates, Inc. (WJE) has performed an investigation of water issues at and around the bell tower and exterior walls of the St. Peter’s Episcopal Church in Oxford, Mississippi. This investigation took place on August 28 and 29, 2013. Stephen J. Kelley, AIA, SE of WJE performed the investigation with Tom Howorth of Howorth Associates. Laboratory studies were performed by Laura Powers of WJE. BUILDING DESCRIPTION AND CONSTRUCTION HISTORY St. Peter’s Episcopal Church is a clay brick masonry structure that is located at the southeast corner of Jackson Avenue and 9th Street. The main entry is through the west side of the bell tower at the northwest corner of the sanctuary. The sanctuary is a basilica plan that faces east. It has seven bays running east- west, with wood hammerbeam trusses defining each bay. On the exterior, the bays are defined by brick buttresses that have been parged with cement. The brick near grade at all four sides is also parged with cement. The sanctuary has a steep roof that is gabled at the east and west and is roofed with asphalt shingles. The steeple above the bell tower is a wooden structure clad in painted pressed-metal