4M COMPANY
Architects Planners Construction Managers
Real Estate Developers
July 25, 2000
The Board of County Commissioners
County of Mercer
103 Mercer County Courthouse
Mercer, Pennsylvania 16137
Dear Commissioners:
In response to your request, we are providing you with a summary of what occurred on Wednesday June 28th, 2000 at approximately 12:45 P.M. in Courtroom #2 of the Mercer County Courthouse. And, secondly, recommendations in regard to repairing and restoring the areas effected.
Background information
Plaster damage in Courtroom #2 as a result of years of water infiltration from the skylights and roof leaks apparently caused the collapse of a 20 ft. section of one of the decorative plaster ceiling beams. Historically, however, courtroom # 1 had many more roof leaks above its ceiling area in the attic. Therefore, as might be expected, courtroom # 1 has the potential to present a much greater clear and imminent danger than that which occurred in courtroom #2.
What is occurring or has occurred?
In courtroom # 1, full height cracks have appeared in several beams and a section of a ceiling beam adjoining a skylight is showing significant signs of distress and most likely will have to be removed. It has extensive cracks and has separated from the ceiling and thus could crash to the floor at any time. Apparently, in the late 1980's, because of water infiltration, a section of deteriorated plaster had to be removed leaving a large hole in the bottom of this beam. Fortunately, this allowed the water to pass through this particular beam, instead of collecting in it. This probably accounted for one of the reasons the metal anchors did not corrode through and this beam did not collapse as the ceiling beam had in courtroom #2.
However, in order to help prevent what occurred in courtroom #2 from taking place in courtroom # 1, we are immediately beginning the emergency repairs in courtroom # 1 as the situation is even more critical. After all the ceiling beams are reinforced in courtroom # 1, we will proceed to courtroom #2 to correct the condition there.
As stated in the publication, Secretary of the Interior's Standards for Rehabilitation of Historic Buildings for structures listed on the National Register of Historic Places (of which the Mercer County Courthouse is so listed), retention of as much of the original fabric or historic materials is required. "The historic character of a property shall be retained and preserved. The removal of historic materials or alteration of features and spaces that characterize a property shall be avoided."
To preserve the decorative plaster ceiling beams within the courtrooms requires strengthening the structural support system which anchors the beams in the ceiling. The entire length of the beams will be permanently supported with three steel plates in strategic areas which will be recessed and painted to match the plaster. It is necessary to provide this type of structural support because of the unknown weakened conditions of the plaster, the corroded metal lath and strap hanger assembly and the integrity of the lead and screw hangers. Additionally compromising the structural soundness of the plaster beams was the increased weight of the light fixtures affixed to the them.
What is being done to repair the courtroom Ceiling beams?
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The existing ceiling lights are to be removed from the beams and placed in three symmetrical bay spacings totaling 12 lights between the rows of beams. This will allow for the eventual replacement of the fixtures with more appropriate historical chandeliers.
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Three continuous steel plates to secure the plaster beams are to be installed using 1/4" thick x 5 1/2" wide flat bar with 3/8" diameter all-thread rods. The rods are to be 12" in length for the side moldings support plates and 18" for the center beam's support plate. They are to be shoe welded at 2'-0" o.c. and provided with two interlocking nuts and one flat washer, installed with a 1/4" x 6" x 6" flat plate with a 7/16" diameter hole centered in each plate to distribute the weight evenly along the attic surface of the concrete deck.
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Every 2'-0" o.c., the attic concrete deck is to be core drilled to allow for these structural beam supports. The steel support plates are to be installed in the recessed soffit panels on the four ceiling beams and also on the perimeter wall cornice beam soffit panels. The perimeter wall cornice is also to be inspected for any structural deterioration to the decorative dentil moldings and brackets and to repair as required.
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All new plaster beams that are to replace the missing or damaged beams are to match and replicate the existing profiles and moldings of the existing plaster beams and to blend seamlessly with the original. Only those portions of the existing plaster beams and moldings that are structurally unsound and weakened beyond repair are to be replaced.
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All steel is to be shop primed gray and free of any surface defects. Field paint all exposed faces to match existing color and finish of the recessed soffits of the plaster beams after installation.
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Because the Courthouse must remain open and the offices and public undisturbed as much as possible, all work must be done after hours from 4:00 P.M. to 12:00 A.M. Work commenced Thursday, July 20th and it is anticipated to be completed August 30th, 2000. Because of the many conditions regarding this type of work, an estimate will be provided for budgetary purposes; however, the work will be done on a time and material basis.
I hope all the above meets with your approval and will be happy to answer any questions that you may have.
Respectfully submitted,
Robert A. Mastriana, A.I.A.
Partner
