RESTORATION CASE STUDY

by Jim Donaghy

RESTORATION CASE STUDY

Dirksen and Hart U.S. Senate Office

Buildings, Washington, D.C.

Project:

Cleaning restoration and repair at Two Senate Office Buildings in Washington, D.C.

Owner: United States Government Senate Superintendent POC:

Phil Chambers

Contractor:

CSCI, LLC Arnold, MD

Masonry Contractor:

CSCI, LLC Arnold, MD

prohibit the work in the winter months. Since the Hart Senate atrium is confined to the interior we can work on this throughout the winter months. The DSOB marble restoration is in 2 phases. What is addressed here is the corrosion stain restoration. This portion of the marble contract is somewhat unique and covers the remediation of corrosion stain removal from marble which is also prevalent in most stone structures that use limestone, marble, granite or even in some cases concrete. The method described herein is the same.

We have contracts for glass, metal frames and stone cleaning and

restoration at the US Capitol and the 3 Senate office buildings, Russell, Hart & Dirksen.. You may recall that the Hart (HSOB) became famous after Sept. 11, 2001 when it was attached with anthrax. This building was shut down for quite some time to fumigate the entire building. This is the first time that the interior atrium marble has been cleaned since that incident. It is rather difficult to reach most of the areas in this 8 story atrium. We

intermittently worked on this project when there was bad weather outside or other

unforeseen problems that prohibits the DSOB job to go forward.

O

ur contract covers the

exterior marble restoration and stain removal of the Dirksen Senate Office Building (DSOB) in Washington, DC as well as the Hart Senate Office Building (HSOB) interior atrium marble cleaning, mortar pointing and repair to interior marble, skylight drywall repair, Mountain & Clouds Art sculpture restoration and cleaning and air duct & vent register cleaning around skylights. We’ve been working on both of these projects simultaneously for about 6 months. The Dirksen had to be completed first due to weather conditions that would

The DSOB had not been cleaned

properly in many years, in fact, maybe never since it’s opening in 1956. The focus of this portion of the DSOB contract was the elimination of all corrosion staining around the building. All of the stains occurred under ledges which these stains are referred to as corrosion. This corrosion turns the white color of the marble a dark brown color and is very difficult to remove. It certainly does not get removed by rinsing them off with a fire hose or for that matter a pressure washer or any other type of water or fluid introduction that will deface the marble surface. There are details to this exterior marble that can easily be damaged by using a hot high pressure system. Our solution was to use poultice and one that we are familiar with. We used the same process that we used when we cleaned and restored the interior of the Smithsonian Institution’s National Museum of Natural History. We used this process then on interior limestone around the rotunda about 5 stories high. It worked well and removed all of the stains that had accumulated over the past 100 years.

First, we demonstrated for the Architect of the Capitol our procedure for this work in the different areas of the building architecture.

There are some areas that present a problem which required a different approach to the cleaning and additional types of chemicals other than the poultice. These areas include details in the marble around the main pediment and pediment arch. In such cases, it is impractical to use a poultice since it would be too difficult to apply the poultice in areas were there are a lot of detail or recesses in the stone fascia or where there are large expanses to keep the poultice moist under plastic for up to 72 hours prior to its drying and removal.

However, about 90% of these areas were cleaned with the poultice. The poultice that we used is an earthen clay type of poultice manufactured by K&E Chemicals called KL - 9. In the poultice procedure, we found that a 72 hour dwell time was sufficient for the stains to come out of the stone. Determining the correct dwell time is a major factor. Too little and you’ll have insufficient results. It does require a bit of trial and error if you’ve not had much experience with this method. We did our testing in plane view since it would not matter if we got it white

Stains such as these are typical under the all ledges.

RESTORATION CASE STUDY

RESTORATION CASE STUDY

as new since that’s what we were shooting for. We just needed to find the minimal dwell time and that was determined to be 72 hours. This time period helps to keep the job rolling along on time schedules for the other procedures so that you don’t loose track of where you are on such a large job. You may have to repeat work unnecessarily since not enough dwell time was allowed on any particular stain. This also ensures uniformity to the color afterwards. In order to attain a minimum 72 hour dwell time the poultice needs to be applied directly to the stain on the stone and then the poultice needs to be wrapped in plastic sheeting and sealed around the edges to prevent air from entering the poultice so that it remains moist during the dwell time. After the plastic sheeting is applied and you’ve reached your limit for the days work you need to mark and date the last sheet.

This will tell you where you left off several days later so that you don’t remove poultice too soon in an area where you ended days earlier. This is true on long expanse on many different levels of a building such as the Dirksen. The Dirksen has 4 different levels of stain removal over 250’ long on 2 sides and over 300’ on another side. Easily you can loose track if it is not marked and dated. After the 72 hour dwell time the plastic can be removed to allow the poultice to dry out. During this dry time the poultice pulls the stain out of the stone. Once the poultice is dried it can be easily rinsed off with low pressure water to remove the poultice and the residual stains on the surface. One final note: In this instance we use hot water as well to increase the effectiveness of the rinse and to eliminate the surrounding dirt so that we can blend the brilliantly clean surface

to the existing surrounding surfaces so that there is not a stark contrast where the poultice was applied. If you do not blend this surrounding stone you will have an obvious line of demarcation which will be almost as noticeable as the stain that was removed. Since it was not the intention of the AOC to clean the entire exterior of the DSOB at this time we needed to take this into consideration and blend the surrounding area, this is a key step. It does require a bit of a knack to get this right. Too much and you’ll wind up cleaning a much larger area to compensate and might still not look right overall.

After the dwell time, the plastic was removed, allowing the poultice to pull the corrosion stain out of the stone as it dried.

Cleaning around an Elephant

T

he Smithsonian Institution

National Museum of Natural History (NMNH), which covers

several entire blocks in Wash-ington, D.C., is 100 years old. The NMNH trademark, the African bush elephant, stands on a large pedestal in the middle of the circular Rotunda and catches the eye of all who enter the museum. The Rotunda is surrounded by limestone, marble, and soap stone columns. With its dome rising approximately 90’, the Rotunda, at the center of the museum, is beautiful and majestic. From the Rotunda, you access all of the exhibits on two levels of the museum open to the public. (The third and fourth levels are closed fro research, storage, etc.)

In mid-December 1999, I was approached by Tino Blanco of B&D Stone to help with the task of restoring the interior limestone of the museum’s Rotunda. The project was under the management of Grunley-Walsh and headed by Lorne Rapp. Their contract consisted of the entire renovation of the Rotunda, which included the cleaning of handrails, guardrails, lighting fixtures, as well as the

limestone, granite, and marble elements. Some plastering and painting in the Rotunda was also necessary. I had several meetings with Tino Blanco and LorneRapp to discuss the architectural plan for my role in this renovation, which called for the removal of stains, grease, chewing gum, ink, adhesives and existing sealer from the limestone. In addition, a large accumulation of dust on the ledges, walls, coffered arches, railings, pediments, etc. needed to be eliminated. It had been 25 years since this undertaking had been carried out. Of course, since that time, the methods have changed considerably for performing such a task. The plan called for all of this work to be done from about 5:00 P.M. to about 6:00 A.M. each weekday so that the museum could remain open to visitors throughout the renovation process. The project was to begin in January 2000 with the completion before Easter.

The Preliminaries

At other preliminary meetings, determinations were made regard-ing the method of cleanregard-ing including chemicals, techniques, and containment. Coating remo-vers would be used to strip the

existing sealer off the limestone and chemicals would be used to clean the limestone. These chemicals had to be rinsed off using high pressure hot water—a challenge in the interior of the museum. The specifications on the architectural drawings called for the use of certain chemicals. This conflicted with the type of chemicals we were accustomed to using for this type of stone cleaning and restoration. Our preferred stone cleaner is

Klenztone. My company has had a long standing relationship with Ed Bleik, of K&E Chemical, who provided input on proper application before any such undertaking Once the issue was resolved, we performed several mock-up test patches on the stone in various places to demonstrate the results of the method and the chemicals. Some of these areas included balustrades, columns, railings, and walls. The entire job, however, consisted of many more architectural stone designs. Because containment was crucial, a great deal of forethought was done on my behalf at some of the earlier meetings to resolve the issue of containment and removal

MEETING THE CHALLENGE

not only the water from the interior power washing, but chemicals and debris as well. We also had to consider the containment of any airborne fumes from the chemicals released into the Rotunda. The Smithsonian is very cautious about any substances being introduced into the environment of the building because of the nature of the exhibits. After all, this the premiere exhibition of some of the finest artifacts in the world, including the Hope Diamond and many rare gems, fossils, preserved wildlife, etc.

Containment

Our method for containment was ingenious and proved quite satisfactory, since during the entire job we did not breach this portion of the contract once. For access to all the stone, Grunley-Walsh erected scaffolding around all the stone from the first floor to the top of the Rotunda, stopping just below the Dome. Partitions were erected around all of the interior hallways on each level, as well as the columns on the first floor. This allowed the exhibits to be opened to the public yet kept visitors out of the renovation work areas. A large screen was placed

(approximately 40’ up) across the entire expanse of the Rotunda. This kept any falling debris from hitting the elephant or damaging anything else. Within the cordoned off scaffolding and partitions areas, we had develop our

containment. Containment was the real focus of the job. First, we constructed a secondary

containment that covered the entire floor area within the work area. This secondary containment consisted of plastic sheeting, taped from the bottom of each piece of limestone and across the floor to trap any chemical or water that may have leaked from the primary containment. This plastic was draped and taped over everything that might be exposed to the water and chemicals. Air containment was another factor that had to be addressed to prevent the chemicals

fumes from penetrating the building outside the work area (since the public would be in the building the very next day). A plastic sheeting barrier

encapsulated the entire scaffold and partitions for this purpose. We spent many man-hours in this preparation before any real work could take place. We bought duct tape and plastic by the cases and spent the first week—six people, eight hours a day—just on plastic and tape applications to cover four floors and encapsulate 20,000 sq. ft. of limestone that was to be cleaned. We used neoprene tarps

Equipment Set Up

After the primary containment was complete, we placed the necessary power washing equipment on the scaffold. Since we were using hot water and high pressure, our system had to remain outside of the building: our generator, hot water burner, and power washer were located on the street in the front of the museum. We used a Hydro Tek SC series system and ran it at 3000 psi at 5 gpm. We chose this one since it is a trailer mounted unit with a 350 gallon water supply tank that could keep up with the demand of

for the primary water and chemical containment. Pumps, located inside the tarps, were used to remove the water, chemicals, and debris through a series of hoses and drums without lids. Each drum housed an additional pump to usher the water and debris through hoses to drums located on the first floor. From there the water and debris was pumped through more hoses, out of the building to the sewage line. It was a simple method that served us well once it was in place and served us during the mock-up trials and job.

I

t’s hard to call it work when you are in Bermuda, particularly when it’s blizzard conditions and flooding back home, but, someone has to do it. Of course everyone associated with our company has become somewhat used to traveling around to different places from time to time when it comes to work. Our employees

Hurricane Felix

The current project that is occupying much of our time came about during one of our quarterly visits to the island back in September of 1995. I arrived two days prior to Hurricane Felix’s attack where I remained throughout the storm and several days afterward.

He was enthralled and immediately began to direct us toward another part of the resort that had the same predicament. Believe me, the more we looked, the more we found. After a couple of days looking we found that practically the entire resort hotel area needed to be treated. After demonstrating our services and agreeing on the amount

from Texas work in Maryland to help on jobs there and vice versa. However, the jobs all of our employees like are the ones in Bermuda, especially the larger ones that will keep them there for longer periods. Such is the case with the restoration of a very fine resort hotel in Bermuda which we are currently working- -

we started the restoration job. It is always difficult working outside the U.S. because in most cases overseas shipment is a major concern. From Baltimore, we had to export all of the rigging equipment, chemicals, power washers, and other accessories, tools and so forth. This was a major task to complete in such a The Marriott Castle Harbour

Resort. CSCI has been conducting business in Bermuda since 1990 exclusively in the building restoration service industry. This venture has been very successful from the onset. CSCI-Bermuda was formed in 1992 and has since had the service contracts with many of the International Banks, and resort hotels, and Bermudian Government facilities providing various periodic maintenances including caulking, surface restoration, power washing and glass restoration & cleaning for these many and diverse properties on the Island.

During and after Hurricane Felix we found ourselves – Tom Donaghy, a partner from Houston, and myself- with nothing to do except lend a hand from time to time during the emergency. Many of the trees around the resort where we were staying were toppled or pushed over revealing or pushed over revealing numerous building areas that were discolored due to algae, mold, and mildew and so on. As we discovered these areas, we brought them to the attention of the resort’s general manager explaining to him that we could abate all of those problem areas if he was interested.

This includes the rigging equipment, swing stage set up, power washer setup and uses, chemical treatments and stone preparation.

I had a consultant, Tom Darragh from GPS, come to Bermuda to examine the property to see if he had any suggestions regarding the different stone surfaces. I believe in all cases it is prudent to have a consultant make further recommendations for future references and possible preservations.

Cleaning Procedures

Since our contract originally covered just the removal of the mildew, mold and algae, I thought it would be wise to extend the contract to cover additional services that should be covered at the completion of the cleaning. The building has had point work done around various locations causing spots of acid washed stone to stand out among the natural looking stone. We will apply a

plastered concrete surfaces to crack and chip. Water is a key ingredient to this type of application, but only the water, not the pressure. The pressure of our machines will deliver approximately 3500 psi in normal uses but we have reduced it to around 800 psi for the protection of the building structures.

We also use a caster-mounted rotary Hydro-Twister to clean the flat surfaces around the pools and entrances as well as the walkways and garden ways. The castle has areas of stone around a chimney that are black due to soot from an oil burning water heater. This stone will be cleaned with Klenztone #1 and a Concrete Stone Preparer. These chemicals are also ideal for the removal of stains in the stone.

The castle is made up of quarried indigenous limestone from England, concrete block with an exterior plastering, cement, various tiles and cedar and redwood dividers around, first in

This contract covers the removal of all algae, mold, mildew attached to the exterior of the buildings. The tourist season in Bermuda is different from the rest of the Caribbean islands; Bermudas’ season begins in April and ends in early October. This winter schedule gives us the right amount of time to complete the castle cleaning prior to its opening. However the hydra-sealing may take some time due to the increased winter weather which is always around the mid to upper 60’s and occasionally raining. We’ll need several good dry weeks to finish the hydra-seal and preservative applications to the wood surfaces. This will probably cause our contract to be extended into May. At present, we have completed about one-half the resort cleaning and have imported all the materials needed to complete the tasks, save any unforeseen necessity, which is usually the case. We find ourselves losing time in most

hydra-seal with a fungicide and pigment to keep the various growths from coming back and to blend all the stone together so they will look uniform. We’ll use a fungicide to do the first cleaning around the property and power wash the surfaces after treatment to remove any dead growth buildup from the surfaces. The machines we use to power wash have 13 hp Honda engines with AR pumps at four gpm. We use a 40 degree nozzle with a large orifice to decrease the water pressure and allow water flow for a good rinse. High pressure is not used to clean this stone as it may cause degradation and provoke the

Tee-side, England where it was marked, dismantled and shipped to the current Tuckers Town site. This great venture began after World War I and was finished in 1931. The Castle Harbour was touted as the premier resort catering to the rich and famous. During World War II, it was turned over to the United States Government for use as accommodations for US troops. In 1958, Bermuda Properties bought the Castle and further developed it until 1984 when Marriott Hotels and resorts negotiated a long term lease. The project began in mid-December 1995 and should be completed by April 1996.