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Application Overview

St. Andrew's Baptist Church in Wichita, Kansas suffered an extensive fire in the kitchen. The structural fire damage was confined to the kitchen; however, the soot and water damage affected about 75% of the structure. The local contractor hired to do the restoration was faced with removing soot and smoke damage from a variety of substrates at the same time.

Substrate

The church is built primarily of white limestone, inside and out. Other surface materials to be cleaned included mahogany trim, brick, concrete block, clear glass, and stained glass windows.

Special Concerns

The glass windows were framed by limestone and wood all extremely sensitive and relatively soft surfaces. Therefore, sand-blasting was not a consideration. The area had already sustained some water damage as a result of extinguishing the fire so power washing was not considered. There was additional concern that any "wet" process would allow the black soot to be absorbed into porous materials.

Previous Methods

Not applicable.

Project Schedule

The project was bid as a two-day job (two people each working 8.5-9 hours each day) and it was completed as such.

Equipment Specifications

An ACCUSTRIP SYSTEM model 12SX with ARMEX® Maintenance Formula and a #8 fan nozzle at 40 psi were used to clean the limestone and mortar, as well as the brick, glass, stained glass, wood trim and railings. Maintenance Formula XL and a #8 fan nozzle at 60 psi were used to remove all the soot from the heavily blackened concrete block walls in the kitchen where the fire started.

Containment

A plastic curtain was put up to keep a majority of the dust out of exposed portions of the attic and the parts of the church that were not being cleaned. Spent ARMEX media was swept up with a broom and disposed of in a dumpster.

Results/Benefits Summary

ARMEX easily removed soot and smoke damage from the limestone and mortar, without any damage or degradation to the limestone. Brick, glass, stained glass, wood trim and railings were cleaned just as easily and successfully (wood usually requires a sealer after cleaning with ARMEX). The production rate for cleaning the limestone and brick was 10 sq. ft. per minute. The heavily coated concrete block walls in the kitchen were cleaned at 4.5 sq. ft. per minute. The wood trim was carefully blasted clean of soot and its finish at approximately one linear foot per second. After two days of blasting, the ARMEX-cleaned church was restored to its former glory.

The devastation resulting from the Iraqi invasion of Kuwait touched every corner of this small country. The Messilla Beach Hotel was the site of some particularly serious damage. Inside, the Iraqi Army used incendiary grenades and gasoline to methodically burn each of the rooms. Outside, concrete walls bore the scars of fire, smoke, ash and graffiti. The fire burned so hot in some areas of the resort that the concrete cracked and loosened.

Several cleaning methods were considered to restore the buildings. Scrubbing with caustic chemicals was one possibility. Low-cost labor is readily available in Kuwait, so labor-intensive cleaning is generally a more viable option than in Europe or North America. However, the owners of the hotel did not want to introduce toxic substances or residue into the guestrooms. The negative effect of chemical cleaners on the surrounding delicate landscaping (a triumph of man over nature in this harsh climate) was also taken into consideration.

Kirk Davis, manager of First Trading & Contracting Group in Kuwait, teamed with the Kuwait Cleaning Company for several small on-site demonstrations. The objective was to show the versatility and safety of the ARMEX/ACCUSTRIP process when used against different types of damage: burned paint, loose concrete, and graffiti. The demonstrations also allowed the cleaning company to estimate their contract pricing. For burned paint they blasted at the higher end (85 psi), still keeping media consumption fairly low at one to one-and-a-half pounds per minute. They increased water pressure and maximized blast pressure to knock out loose and damaged concrete.

The demonstrations paid off, for the Kuwait Cleaning Co. was awarded the contract. Although it's not yet business as usual at Messilla Beach, hotel guests are returning and occupying rooms as soon as they are cleaned and restored. This has provided some wonderful "free" advertising, since guests and potential customers can safely observe the ARMEX/ACCUSTRIP process in action all around them. (Had toxic chemicals been used, the entire hotel almost certainly would have been closed until all work was complete.) It's gratifying to know that a process so useful and well respected in industry can play such a visible, vital role in the rebirth of a country.

Application Overview:

Fire damaged the ninth floor of a 12-story apartment building in Seattle, Washington, requiring removal of carbon and soot from approximately 1,100 square foot of the interior hallway.

Substrate:

The hallways were built of "blond" brick.

Special Concerns:

The building owner required a waterless cleaning method to avoid leakage to lower floors. Also, although the damaged wing was evacuated, resident were occupying other parts of the ninth and surrounding floors. For this reason, the owner did not want to use hazardous chemicals. Noise was not a problem, as the compressor and blasting equipment were outside on the ground.

Project Schedule:

The cleaning was accomplished in two days and a total of 32 man-hours, including mobilization, cleaning and demobilization. The contractor cleaned approximately 75-80 square feet of wall per hour.

Equipment Specifications:

An ACCUSTRIP SYSTEM® Model #16 was fitted to an Inventive Machine Corporation Blast-n-Vac® unit to eliminate dust from the dry blasting. Slight modifications to the Blast-n-Vac were required to make it compatible with the ACCUSTRIP SYSTEM. The ACCUSTRIP was powered by a 375 cfm compressor. Although approximately 80 feet of hose was required to reach the work area, pressure drop off was minimal. The contractor accomplished the cleaning using one to three pounds of ARMEX® composite media per minute at 40 to 50 psi.

Containment:

The Blast-n-Vac eliminated the need for dust containment. However, a floor-to-ceiling clear plastic curtain was used primarily to prevent people from tripping over the equipment.

Results/Benefits Summary:

The customer, City of Seattle Housing Authority, was quite pleased with the speed and results of the work. The agency also liked the fact that the residents of this high rise – many of whom are elderly or disabled—were not exposed to noxious fumes or dangerous chemicals.