UF Homepage

Home>>Past>>Deconstruction>>Building Deconstruction: Reuse and Recycling of Building Materials (page 1)

Page 1 | Page 2 | Page 3 | Page 4 | Page 5
 
Building Deconstruction: Reuse and Recycling of Building Materials

Prepared by:

Powell Center for Construction and Environment, University of Florida

PO Box 115703, Gainesvil\-le, Florida USA 32611-5703, Tel: (352)-392-7502

On behalf of:

Alachua County Solid Waste Management Innovative Recycling Project, August, 2000

Acknowledgements

The Construction Site Supervisor for this project was Mr. Kevin Ratkus. Data Collection was performed by Mr. Sean McLendon and Mr. Bradley Guy. The Principal Author of this report was Mr. Bradley Guy, including materials prepared by Mr. Sean McLendon.

ABSTRACT

The PCCE deconstructed six (6) houses during 1999-2000 to examine the cost-effectiveness of deconstruction and salvage when compared to traditional demolition. This research was funded through the Florida Department of Environmental Protection (FDEP) Innovative Recycling Projects grant program through Alachua County. The one and two-story houses that were deconstructed represent typical Southeastern US wood-framed residential construction from 1900 to 1950. Regulatory issues included the costs and   implementation of environmental, demolition, and historic permitting practices in the Gainesville / Alachua County, Florida region, and handling of lead-based paint (LBP) materials, and asbestos containing materials (ACM). Worker safety issues and technical issues included protection from environmental and site hazards and a case-by-case materials management process for each building. Reuse and materials redistribution scenarios include on-site and off-site redistribution and associated costs and benefits. Over 500 pieces of salvaged lumber were visually graded by the Southern Pine Inspection   Bureau, to understand the damage of use and the deconstruction process on salvaged lumber in reducing use in structural applications.

KEYWORDS: deconstruction, selective dismantling, C&D wastes management, building salvage, building materials reuse.

Project Background

From August, 1999 to May, 2000 the Powell Center for Construction and Environment, University of Florida, with funding from Alachua County Public Works Division and the Florida Department of Environmental Protection (FDEP) deconstructed six (6) wood-framed residential structures in Gainesville, Florida. University students provided labor on the first three buildings and Americorps*NCCC members worked on the second three. Houses were acquired mainly through word of mouth. Permitting processes included issues of historic preservation, demolition delay requirements, licensed contractor requirements and environmental, safety and health certifications for hazardous materials management, utility disconnections, and septic tank removals. Each house was tested for lead-based paint (LBP) and asbestos containing material (ACM). All structures were completely removed from the site, comparable to a total demolition. Time and activity data was collected for each worker and all associated costs and estimated revenues from salvaged materials were calculated. Each building was also estimated for demolition in order to make a comparison with deconstruction and salvage. There was considerable variety in the buildings’ conditions, the location of the buildings, and the efficiency of each deconstruction.

Buildings Summary

The structures ranged from approximately 1000 to 2000 SF and were both single and two-story. The oldest structure was built in 1900 and the youngest built in 1950. The typical construction was a raised wood floor structure on brick and/or concrete piers, light wood wall-framing, roof rafters, and interior and exterior wood cladding and sheathing. Two structures had plaster and lathe interior wall finishes. In one case gypsum wallboard was applied directly over the wood beadboard interior wall finish. One structure also had two roof finishes, metal over asphalt shingles, and two floor finishes, an oak floor laid directly on top of a pine floor. All of the structures had rot from water damage principally in kitchen or bath floor areas, but also including wall areas at leaks from the roof.

Table One - Summary of Buildings

Building address #

2930

711

14

2812

901

3650

Built

1915

1945

1900

1900

1920’s

1950

Stories

1

2

2

1

1

1

Light framed wood construct.

Y / CMU

Y

Y

Y

Y

Y

Size (SF)

2,014

1,436

2,059

1,238

992

1,118

Urban or rural-sized parcel

Rural

Urban

Urban

Rural

Rural

Rural

Additions

Y

Y

Y

Y

Y

Y

# of additions

3

1

1

2

3

1

Internal renovations

Y

N

Y

N

Y

N

Inhabitable

Y

N

Y

N

Y

Y

Require major repair

N

Y

N

Y

N

N

Asbestos    

Exterior wall finish

Y

N

N

N

N

N

Roofing

N

N

Y

N

N

N

Insulation

N

N

Y

N

N

N

Floor tile

Y

N

Y

N

N

Y

Drywall

N

N

Y

N

N

N

Abatement

Y

N

Y

N

N

Y

Lead-based paint    

Interior trim

N

N

Y

Y

N

N

Exterior trim

Y

Y

N

Y

N

Y

Interior surfaces

N

Y

N

N

Y

N

Exterior surfaces

N

Y

Y

N

Y

Y

Reason for removal    

Redevelopment site

Y

Y

Y

Y

 

Taxes / expense

 

Y

Safety / disuse

Y

   

Homeless / fire hazard

Y

   

 

All of the structures had additions, and these were typically for; 1) adding enclosed living space, 2) adding kitchen and bathroom facilities on older structures, 3) enclosing an existing open porch area. Four (4) out of six (6) could be made habitable, and three (3) of six (6) had been recently occupied prior to the building’s removal. One (1) house had been occupied by homeless persons without heating, kitchen, or bathroom facilities. Three (3) of the six (6) structures were found to have asbestos containing materials (ACM) requiring abatement. Two  (2) of the structures contained only non-friable asbestos which could have been “wet demolished” by mechanical means but would have required the entire demolition wastes load to be disposed off in a hazardous materials landfill. Only one building had LBP only on the inside, typically LBP was found on exterior window and door trim, where it was used in gloss and semi-gloss paint for durability.

 

Two (2) of the six (6) buildings were on property slated for immediate commercial or multi-family redevelopment, two (2) were on property slated for long-term redevelopment, and two (2) buildings were on land not slated for redevelopment. The latter two (2) structures may have been left vacant for an indeterminate length of time if they had not been used for this project. During the course of the project, one building verbally committed to the deconstruction project, on a site slated for commercial redevelopment, was demolished. In addition, two candidate buildings, on sites slated for redevelopment, were moved. One structure that was considered for the project was considered too dilapidated for a reasonable deconstruction and another was passed over due to scheduling conflicts and was subsequently partially renovated by the owner. The average size of the six structures was 1,476 SF.

 

Based upon literature review and anecdotal information, this sample of structures would appear to be representative of residential demolitions in the United States. Also, approximately 94% of all residential buildings built each year in the US are light wood-framed construction (NAHB, 1994).

 

Data Collection

On-site labor was documented by recording each worker’s activities on a 15-minute time increment.  There have been several well-documented deconstruction pilot projects in the US with this detail of data collection, most notably the Fort Ord Pilot Deconstruction project conducted by the Fort Ord Reuse Authority  (Cook, 1997) and the Riverdale Pilot Deconstruction Project conducted by the National Association of Home Builders Research Center  (NAHBRC, 1997). These projects provided models for creating the data collection process. Data is divided into two categories; the deconstruction of the structure and the processing of the salvaged materials. The cost of a traditional demolition was calculated for each structure, including disposal costs. Salvage revenues were estimated using a percentage (25-50%) of retail prices from local building materials suppliers and the experience of a former used building materials store owner/operator in Gainesville, Florida. Disposal costs were estimated by weight and costs data provided by the wastes haulers for the project.

Worker labor activities were sub-divided into categories by the location in, or component of, the building in order to calculate the costs of deconstructing a particular component of the building, and the costs to salvage a unit of a particular material. The latter information was used to assign a unit cost of extraction and processing that could be compared to the pricing units for materials, i.e. number, linear feet, or board foot of material. Labor productivity data was collected in the following task categories:

(S) upervision 

Directing and planning the flow of work on the job site.

(Decon) struction

Labor involved in the initial removal of materials from the structure. Any manual or mechanical procedure required to remove materials for salvage, either the direct handling of a material or removing other materials to gain aPCCEss to the salvage material.

(Demo) lition

The hand or mechanical removal of building materials for direct disposal.

(P) rocessing

Preparing materials for redistribution in reusable form.  Denailing is the most typical processing activity.

(N) on-production

No work is being performed. Includes breaks and the unloading and clean-up of daily tools, but excludes lunch.

(C) lean-up / (Dis) posal

Sweeping and/or removing debris or demolition materials from a work area and/or disposal into a roll-off container. 

L) oading/unloading

Loading or unloading materials from the site onto a truck for transport and at the final storage area.

The largest percentage of time on any deconstruction was the deconstruction activity, an average of 26% of total time. The next greatest percentage of time was spent in processing materials at an average of 21%.  Disposal and cleaning required an average of 17% of total time. Demolition required an average of ~12% of total time. The house with the largest percentage of time spent for deconstruction was the house at 901 SR 301 (47.8%). This house was being removed for redevelopment and had a very short time frame for the deconstruction. It was also located on a major highway in the corner of a shopping center site, and materials were redistributed by placing them neatly in separate piles at the site and posting “Free Materials” signs to encourage passersby to remove the materials themselves. All of the materials were removed within one day after the completion of the deconstruction.

 

Table Two - Sample Data Sheet

Location:

 

 

 

Completed by:

 

Date:

Worker

#1

#2

#3

#4

#5

#6

#7

7:30

 

 

 

 

 

 

 

Activity

 

 

 

 

 

 

 

Room

 

 

 

 

 

 

 

Location

 

 

 

 

 

 

 

Material

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Activity

Supervise

Decon

Process

Demo

 

 

 

 

S

Dec

P

Dem

 

 

 

 

Clean/Disposal

Non-Prod

Load

 

 

 

 

C/Dis

 

N

L