J.5 2024-08-27 Memo of Advisory Panel Comments on ICR Final Report.pdf

UNCLASSIFIED // For Official Use Only

MEMORANDUM

Document2

Date: August 27, 2024

To: Ece Kilic, AOC Project Manager Work Order Number: 90305.018

From: Lonnie Hovey, AIA, FAPT Contract Number: AOC19C3007

Subject: Comments on ICR Final Report Project: President’s Rm. Advisory Panel

CC: M. Oehrlein, B. Ramsay, T. Williams, File

Members of the President’s Room Advisory Panel reviewed the PHASE 1-3 DRAFT REPORT on the PRESIDENT’S

ROOM CEILING ANALYSIS submitted August 2, 2024 by Integrated Conservation Resources, Inc. (ICR), and provided the following overall and specific comments and suggestions to improve the report for the project record.

Overall comments:

• The ICR report needs more explanation to develop a compelling case for the recommendation to shore the ceiling. The slides shown in the August 16 presentation will bolster this explanation, but more is likely needed.

• The ICR report needs an Executive Summary to concisely describe the reasons for testing, the testing done, findings, and recommendations.

• Similarly, the goals of paint analysis should be described in the final ICR report to focus the information presented. Slides in the GPS presentation outlined their goals and findings very clearly.

• The report should answer the question: Which NDT methods are reliable predictors of voids behind the plaster, and which are not?

• The entire ICR report needs copy editing to eliminate spelling errors and other typographical errors.

• The recommendation is reiterated that CUA’s report be updated to provide greater clarity in what they are measuring (mobility) vs. what they are inferring (delamination). The report mischaracterizes their findings in the absence of physical data (which they did not have at the time of their testing). If this is not updated, ICR’s report needs to make a clear statement prior to CUA’s report explaining this difference.

• The report needs a prioritized and clear list of recommendations, including clarification of what constitutes

“monitoring,” recommended frequency of “regular monitoring,” and by whom. Clear, actionable steps for AOC must be provided.

• Put bookmarks in the final report pdf, in order to navigate 300+ pages.

Specific comments:

• Page 3: Brumidi worked in the Capitol primarily between 1855-60 and intermittently after.

• Page 4, para. 1: “The ceiling is assumed to be a brick vault 12” deep” – did ICR receive original drawings, and can we update to state what drawings show?

• Page 4, para. 2 and Fig. 3: can we update based on recent testing?

• Page 7: what is the difference between “deflected” and “detached” plaster as defined here?

• Page 7: SLDV definition – add that it uses sound to create the displacement.

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• Page 9: Not certain why you have reached this conclusion re: alterations of the interstitial space. Re:

systems in the ceiling of the room. MO indicates that there are none except electrical and old gas piping.

There is no plumbing in the space above, the roof drains are vertical and located in exterior wall chases.

Those that have been rerouted to the interior are still vertical, not concealed in the floors.

• Page 11: 1921: At some undocumented point in time after the failure of the plaster at the center of the ceiling a painted canvas was installed to cover the new plaster. The painting was apparently not well executed and with the permission of the prior curator, Barbara Wolanin, the canvas was removed during the 1995 conservation work. It was left in the curator’s office, current disposition unknown.

• Page 11: 1920-28 The fresco repairs by Comins would have required removal of the damaged plaster. Text in GPS report indicates “repainting.”

• Page 13: “Any offsets in the cracks were smaller than the density of the laser scan” – what was the density?

Please provide the density of the laser scanning. There is no description anywhere in the document.

• Page 14: somewhere please indicate that all photographs taken during the investigation have been submitted to the AOC. We assume, but it is not stated.

• Page 14, Fig. 7: Use an arrow to clarify area of retouching (or clarify in caption)

• Page 15, Fig. 8: Use arrows to identify areas of efflorescence (professionals know, but others don’t) as it looks quite similar to the figure’s veil.

• Page 15, Figs 9-10: Need arrows (maybe multiple colors for Fig. 10 if multiple conditions shown)

• Fig. 11: Please document the locations of the reveals in an overall plan.

• Page 18, Fig. 12: Fix caption to be more precise about red and orange areas. Fig. 12 is a map of sounds, not a map of attachment/detachment.

• Page 19, 20, Fig. 13 & 14: Is this the 2003 data or the most recent data? Please add date and clarify that the mapping represents only vibration differentials not areas of detached plaster.

• Page 19, 20, Fig. 13 & 14: Need units on scale. I don’t see any colors in the range besides blue and red. No purple. Even the light red in the image isn’t represented on the scale. Clarify.

• Page 20, Fig. 14 – remove “detachment” from caption, as this hasn’t been shown. This is the same image as in Fig 13, showing mobility/vibration – not detachment.

• Page 20: Discussion of 2003 (page 19) or 04 (?) and 2023 comparison again characterizes the scans as detachment. Please correct.

• Page 21, para. 1 – plaster ceiling is 1-1.5” thick.

• Page 21, Crack Mapping, Methodology: what about cracks between 0.14-0.016” thick? (typo?)

o How do you differentiate between “cracks”, “crazing”, and “fissures”?

• Page 21, Findings: “suspected” correlation between sounding and giornata is unfounded per Figure 14, which shows giornata in blue and red areas. The giornata are in both low and high areas and cross over both areas.

• Page 22 and 25: “signs of water infiltration” these have not been previously described or discussed. Where are these locations and what are the indicators of moister infiltration?

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• Page 26-27: Reference Figs 21 and 22 in the text. Clarify that “LM” and “MM” are the low and medium mobility samples. Please include the photos of the high mobility sample removal. Please use the sample numbers in the text and figures and provide a full ceiling image to show the sample locations.

• Page 26 Findings: mortar remained attached to the back of the plaster sample, but the base coat did not appear keyed into the mortar joints. How can this be?

• Page 28: Does the petrography help us understand the causes of observed cracking?

• Page 29: Isn’t high mobility also correlated to plaster thickness?

• Page 29, para. 2: Water entering plaster from the brick? New information – what is the basis? Need to explain earlier in the report. The signs of water infiltration have not been previously described. The posit that moisture from the brick has weakened the plaster is not substantiated.

• Page 29: Fig. 25 seems out of place and comes from nowhere. Figure 25 is unexplained, what surface conditions? Should be back in Observations/Findings, not analysis. What is the basis for this? What “surface conditions” lead to the inference of moisture infiltration? “substantial portions of the ceiling are detached” is not substantiated.

• Page 29, para. 3: “though substantial portions of the ceiling are detached” – this is not supported by the data.

Rewrite.

• Page 29: detachment was between brick and base coat. Not consistent w/photos, which show thin layer of base coat on brick.

• Page 30, Fig. 26: last column – find other words for “attached”, “damaged”, and “borderline” – these are NDT results and need to describe vibration, not inferred attachment.

• Page 30, Fig. 26: Samples 10, 12, and 13 do not have good correlation. 3 out of 13.

• Page 30, Fig. 26: Add plaster thickness as a column.

• Page 30, Fig. 26: Sample 13: what does “(AP)” mean? Include all samples in the chart.

• Page 30: Fix caption of Fig. 27 – does not indicate detachment; indicates sound and vibration, respectively.

Include locations of drills on both images in Fig 27.

• Page 31, Fig. 28: remove “attached” from caption. Does not indicate attachment; indicates sound.

• Page 30-32, Figs. 27 - 29: correct descriptions. The mapping does not indicate detachment or compromised plaster. Detachment is being surmised by interpretation of all data.

• Page 31: “worsening conditions” – change to “possible” or “apparently worsening conditions”. Some areas look like they got better! Are you sure the scales and density of data are the same? (scales should be displayed in image)

• Page 31, Fig. 29: remove “attachment” and “detachment” from caption. These are sounds and vibrations.

• Page 32: Re: “plaster was likely the same across the whole ceiling,” add “…but this has not been confirmed by sampling plaster in the areas of fresco.

• Page 32: We suggest more rigor in describing how plaster findings relate to observations: cracking, etc.

Plaster has “deficiencies”, but how does this impact its appearance or performance?

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• Page 33 Recommendations: We suggest more drilling in the frescos to provide more data and correlation to support shoring ceiling. What is the significance of more voids?

o Describe in detail why vibration and environmental monitoring is needed. What information will be provided, how will it be used, and why is it important?

o How do you propose to install monitors in the brick vault?

o GPR at Press Room above needs to include drilling to understand substrates.

o Two months of monitoring is insufficient. Environmental needs to be through a full cycle of heating and air conditioning; measurement of air flow and resulting micro-conditions in the room could also be useful. Vibration during only a recess period when few people are in the building would be almost useless.

o Installing shoring of the ceiling is unlikely to be palatable to AOC or the Senate leadership. An alternative may be to suspend use of the room until further investigation or treatment can be completed, realizing that this will provide only life safety and not ensure preservation of the historic decorative work.

o Provide details of a long-term monitoring program for the ceiling; what, how, and who.

• ANA Report: Appendix A and B need clarity in results reported: not attachment but sounds. (Attachment is inferred, but sound is what’s measured.)

• Page 216 (CUA report): Abstract: SLDV identifies areas of higher mobility, not detachment. Detachment is inferred. Need clarity in this language. (That hasn’t been shown yet.)

• Explain why areas of plaster sampling and drilling were infilled with Plaster of Paris, as opposed to another material.

• Page 289: Highbridge report Exec summary states there is shrinkage cracking in the plaster but that it’s normal. Fully carbonated and cured. Put in ICR report; currently, it doesn’t fully characterize the plaster the way the ICR report does.

• Page 293: “the base of each layer is a cohesive break within the scratch coat” – this is worth noting that in all

4”x4” samples, there were no voids. Need to present this data somehow/somewhere, perhaps at end of table in ICR report.

• Page 342: reviewed plan and section of Press Gallery S-316: what did you find? Is it consistent with ANA’s sketch?

• Page 345: what did you find re: MEP in President’s Room ceiling? (Or no info?)

• Page 357: recommend providing plan with just drilling and samples (red) to focus on plaster (keep plan with red and green for comprehensive picture of phase 3 sampling)

• Page 357: We have 14 drill holes, plus calibration, plus 4 samples to show mobility vs voids, thickness, etc.

Show all in one table. (Table currently has only 13 drill locations.) Section is missing data for HM2 without explanation. Explain function of “calibration” hole and whether we have data from that to include.

• Page 357: PR-W4 “removed from analysis”. Any explanation for observed anomalies? Possible repairs?

Does it correlate to any data from previous analyses or reports?

• Need a map of attached, detached (voids)

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Respectfully submitted.

Lonnie J. Hovey, AIA, FAPT