Historic Preservation - Technical Procedures
Removing And Replacing A Built-Up Asphalt Roof
Federal Bldg/Us Courthouse, Eau Claire, Wi - Chicago, Il
Thermal And Moisture Protection
Built-Up Asphalt Roofing System
Removing And Replacing A Built-Up Asphalt Roof
REMOVING AND REPLACING A BUILT-UP AS= PHALT ROOF
A. This procedure includes guidance on the removal of
deteriorated built-up roofing, insulatio= n, flashings,
wood blocking and equipment pads, and replacing with new
B. For additional guidance on inspecting and repairing flat
roof systems, see 07500-01-S, 07500-02-S, 07510-01-S and
C. Safety: The employer is expected to work in accord= ance
with OSHA standard.
D. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precaution= s
4. Quality Assurance
5. Delivery, Storage and Handling=
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).
A. American Society for Testing and Materials (ASTM), 100
Barr Drive, West Conshohocken, PA 19428, (610) 832-9585
or FAX (610) 832-9555.
A. Roofing System: An assembly of related compo= nents
consisting of the following:
1. Preformed above deck roof insulation.
2. Built-up bituminous roofing.
3. Built-up base flashings and seals.
B. Non-Nailable Substrate: Any substrate for built-up
roofing which is not intended to receive and hold
mechanical fasteners such as cast-in-pla= ce concrete,
precast concrete, block or board insulat= ion, or
lightweight insulating roof fill.
C. Bitumen: Coal-tar pitch or asphalt.
D. Built-Up Flashing: Any non-metallic bitumino= us flashing,
including fabric and felt, applied with hot-mopped
asphalt or cold process bituminous plast= ic flashing
A. Product Data: Submit manufacturer's technical product
data, installation instructions and recommendations for
each type of roofing product required. Include data
substantiating that materials comply with requirements.
1. For asphalt bitumen, provide label on each
container or certification with each load of bulk
bitumen, indicating flash point (FP), finished
blowing temperature (FBT), softening point (SP) and
equiviscous temperature (EVT).
B. Shop Drawings - Tapered Insulation: Submit shop drawings
for the tapered insulation system. Shop drawing shall
include plan layouts having high point and low point
dimensions. Details shall be provided which show
clearances at base flashings, counterfla= shings, fascias,
copings, curbs, etc.
C. Samples - Aggregate Surfacing: Submit 3-lb. Samples of
aggregate surfacing material, flashings, insulation,
fasteners, roofing cement and roofing membrane.
D. Design Data/Test Reports/Certificates:
1. List of Materials: Furni= sh, with the certificates,
a list of materials propo= sed for use in the roof
system, including name of manufacturer, for
2. Certificates for Bituminous Materials: Furnish the
following certification, in triplicate, endorsed by
the built-up bituminous roofing materials
a. That all materi= als in the roofing system are
chemi= cally and physically compatible.
b. That the materi= als meet all the specified
requi= rements, referenced specifications,
stand= ards and tests.
3. Certificates for Insulation: Furnish the following
certifications, in tripli= cate, from the
manufacturer of the roof insulation:
a. Certificates, signed by the Contractor and the
insul= ation manufacturer, stating that
insul= ation, including cant strips, conform to
speci= fied requirements, the thickness for the
speci= fied "U" factor, and that the materials
are proper for use on this project and in
conju= nction with the specified roof system.
4. Certificates for Materials Over Different Deck
Types: Furnish evidence of approved laboratory
labeling, listing or certificates attesting that
materials and method of installation over various
deck types meet specified test procedures and
E. Manufacturer's Instructions/Field Reports: Submit daily
softening point test reports on samples of asphalt used
on project, taken at beginning of each day's work and at
2-hour intervals during course of the work thereafter.
Test by Ring and Ball Test, ASTM D2398, or similar
recognized test method. Submit samples to independent
laboratory for testing or perform tests in field, at
F. Warranty - Manufacturer's Certification, Bulk Bitumen:
Submit manufacturer's certification indicating that bulk
bituminous materials (if any) delivered to project comply
with required standards. Include quantit= y, statistical
and descriptive date for each product. Submit certificate
with each load before it is used.
1. Include continuous log showing time and temperature
for each load of bulk bitumen, indicating date
obtained from manufacture= r, where held and how
transported prior to final heating and application
1.05 QUALITY ASSURANCE
A. Manufacturer Qualifications: Provide primary produ= cts,
including each type of roofing sheet (felt), bitumen,
composition flashings and vapor retarder, produced by a
single manufacturer, which has produced that type product
successfully for not less than 3 years. Provide secondary
products only as recommended by manufact= urer of primary
products for use with roofing system specified.
B. Installer Qualifications: A single Installer (&quo= t;Roofer")
shall perform the work of this section; and shall be a
firm with not less than 5 years of succe= ssful experience
in installation of built-up roofing systems similar to
those required for this project and which is acceptable
to or licensed by the manufacturer of primary roofing
1. Installer Certification: Obtain written
certification from manufa= cturer of built-up roofing
system certifying that installer is approved by
manufacturer for installa= tion of specified roofing
system. Provide copy of certification to
Contracting Officer prior to award of roofing work.
2. Installer's Field Supervision: Installer must
maintain full-time superv= isor/foreperson on jobsite
during times that roofing work is in progress.
Supervisor must have minimum of 5 years experience
in roofing work similar to nature and scope of
C. Pre-Application Roofing Conference: Approximately two
weeks prior to scheduled commencement of built-up roofing
installation and associated work, meet at project site
with Installer, installer of each compon= ent of associated
work. Lifters of roof-top units and other work in and
around roofing which must precede or follow roofing work
(including mechanical work), the Contrac= ting Officer,
Government, roofing system manufacturer's representative,
and other representatives directly conce= rned with
performance of the work including (where applicable)
Government's insurers, test agencies, and governing
authorities. Record (Contractor) discuss= ions of
conference and decisions and agreements (or
disagreements) reached, and furnish copy of record to
each party attending. Review foreseeable methods and
procedures related to roofing work, including but not
necessarily limited to the following:
1. Tour representative areas of roofing substrates
(decks), inspect and discuss condition of
substrate, roof drains, curbs, penetrations and
other preparatory work performed by other trades.
2. Review roofing system requirem= ents (drawings,
specifications and other contract documents).
3. Review required submittals, both completed and yet
to be completed.
4. Review and finalize constructi= on schedule related
to roofing work and verify availability of
materials, Installer's personnel, equipment and
facilities needed to make progress and avoid
5. Review required inspection, testing, certifying and
materials usage accounting procedures.
6. Review weather and forecasted weather conditions,
and procedures for coping with unfavorable
conditions, including possibility of temporary
roofing (if not a mandato= ry requirement).
D. Compatibility: All materials provided shall be
compatible with each specified component of the built-up
roofing system. All materials shall be approved by the
manufacturer of the roofing materials for use with this
E. UL Listing: Provide built-up roofing system and component
materials which have been tested for application and
slopes indicated and are listed by Under= writers'
Laboratories, Inc. (UL) for Class A external fire
1. Provide roof covering materials bearing
Classification Marking (UL) on bundle, package or
container indicting that materials have been
produced under UL's Class= ification and Follow-up
E. FM Listing: Provide built-up roofing system and component
materials which have been evaluated by Factory Mutual
System for fire spread, wind-uplift, and hail damage and
are listed in "Factory Mutual Appro= val Guide" for Class
1. Provide roof covering materials bearing FM approval
marking on bundle, package or container, indicating
that material has been subjected to FM's
examination and follow-up inspection service.
F. Condition of Surfaces: Decks to which roofing system is
to be applied shall be sound, dry, inclu= ding flute
openings of metal decks, clean, smooth, and free from
projections. Application of roof system components shall
not progress when there is ice, frost, surface moisture,
or dampness visible on the roof deck. The Contractor
shall be responsible for damage to the deck or structure
due to his trafficking across same, or to loads imposed
by him in any form. Evidence shall be submitted that
roof deck surfaces, and all slopes to roof drains and
outlets have been checked, and are appro= ved, for
installation of the roof system before installation of
any roofing is started. Joints in deck shall be sealed
as necessary to prevent drippage of bitumen into the
building or down exterior walls.
1.06 DELIVERY, STORAGE AND HANDLING
A. Packing and Shipping: Roofing materials shall be
delivered with manufacturer's labels and seals intact and
legible. Materials delivered in bulk shall be
accompanied by a certificate from the manufacturer,
stating that the material complies with the specified
B. Storage and Protection:
1. Store and handle roofing sheets in a manner which
will ensure that there is no possibility of
significant moisture pickups. Store in a dry, well
ventilated, weather-tight place. Unless protected
from weather or other moisture sources, do not
leave unused felts on the roof overnight or when
roofing work is not in progress. Store rolls of
felt and other sheet materials on end on pallets or
other raised surface. Handle and store materials or
equipment in a manner to avoid significant or
permanent deflection of deck.
2. Use forklift cradle to lift insulation pallets to
roof deck; do not use sling. No more insulation
shall be stored on the roof than can be used in one
3. Felt rolls and insulation piles which are stored on
roof overnight shall be covered with tarpaulins,
not plastic. Coverage shall be complete, with
tarpaulins extending to bottom to prevent exposure
in wind. Material shall be stored in such a manner
so as not to exceed 20 PSF loading on roof.
C. Mineral Aggregate: The aggregate shall be delivered in
dry condition. If yard gravel is wet, it may be oven
dried at an asphaltic batching plant. Aggregate piles at
site shall be completely covered with tarpaulins.
1.07 PROJECT/SITE CONDITIONS
A. Environmental Requirements:
1. Proceed with roofing work only when existing and
forecasted weather condit= ions will permit work to
be performed in accordance with manufacturer's
recommendations and warra= nty requirements.
2. Roofing system materials shall not be applied
during rain or snow. Applications may be continued
in cold weather subject to the following
a. Comply with all provisions of these and the
manuf= acturer's specifications.
b. Do not overheat bitumen to compensate for
c. When temperature drops below 40 degrees F.,
use insulated buckets to carry hot bitumen;
mop manually no further than 5 feet in front
of felt rolls and immediately unroll felt over
bitum= en; immediately apply top pour of bitumen
and aggregate before stored head dissipates in
B. Temporary Protection: Contractor shall be responsi= ble for
protection of spaces and contents below roof deck from
water leakage. Roof deck shall never be left exposed
overnight or during inclement weather.
C. The contractor shall be responsible for protection of
spaces and contents below roof deck from water leakage.
Roof decks or insulation shall never be left exposed
overnight or during inclement weather. Temporary
membranes with open seams, such as plast= ic or loose
roofing felts, shall not be used to provide protection.
A. Special Project Warrantee: Submit 2 executed copies of
standard 2 year "Roofing Guarantee&= quot; on form included at
end of this section, covering work of this section
including roofing membrane, composition flashing, roof
insulation, vapor barriers (if any), and roofing
accessories, signed and countersigned by Installer
(Roofer) and Contractor.
B. Manufacturer's Warranty: Submit executed copy of roofing
manufacturer's standard "Limited Service Warranty"
agreement including flashing endorsement, signed by an
authorized representative of built-up roofing system
manufacturer, or on form which was publi= shed with product
literature as of date of contract docume= nts, for the
period of 10 years after date of substan= tial completion.
C. Defects: Conditions which may be detrimental to
completion or performance of specified work shall be
reported in writing to the Contracting Officer prior to
commencing such work and such work shall not start until
defects have been corrected. No claim by the Contractor
concerning defects will be allowed if made after starting
A. Insurance and Code Requirements: Provide materials=
complying with governing regulations, and which can be
installed to comply with the following:<= br>
1. Factory Mutual requirements for "Class I" or
"Noncombustible,&quo= t; including zoned wind resistance.
2. Underwriter's Laboratories "Fire Classified" and
"Class 60" wind uplift resistance.
B. All material used shall be asbestos free.
C. Temporary Roofing Membrane: 2 plies perforated No. 15
asphalt saturated organic felt complying with ASTM D226,
Type I, set in and glaze-coated with hot mopping of ASTM
D312, Type III asphalt.
D. Vapor Barrier (Retarder):
1. Bituminous Vapor Barrier (Reta= rder): 2 plies
perforated No. 15 asphalt saturated organic felt
complying with ASTM D226, Type I, 1st layer nailed,
2nd layer set in and glaze-coated with ASTM D312,
Type III Asphalt.
E. Roof Insulation:
1. Tapered Rigid Board Insulation: Boards shall be 24"
wide, the tapering system composed of boards having
a slope of =AC" and =AB" per foot. Installation shall
be in accordance with manufacturer's
specifications, using type III asphalt. Junctures
at valleys shall be mitred (not laced). Contractor
shall furnish roof plan drawings showing all slopes
and valleys details. Otherwise same as paragraph
2. Glass-Fiber Board Roof Insulat= ion: Rigid glass-
fiber boards of thickness= es indicated, with k-value
of 0.27 at 75 F (24 C), with integrally bonded top
covering of asphalt-impre= gnated felt or Kraft
paper; comply with ASTM C726; manufacturer's
standard sizes except as otherwise indicated.
Provide for flat and tapered installation.
F. Built-Up Roof Membrane System:
1. Nailable-Deck Asphalt/Glass-Fi= ber/Aggregate Roofing
(NAGA-BUR): Provide built= -up, aggregate-surfaced
roof system with asphalt bitumen and glass fiber
ply felts for lay-up as indicated:
a. Sheathing Paper: Single-ply of 5-pound rosin-
sized sheathing paper.
b. Ply Felts: 4 plies of asphalt-impregnated
glass= -fiber felts, complying with ASTM D2178,
c. Interply Bitume= n: Roofing asphalt, complying
with ASTM D312, Type III.
d. Comply with NRCA Roofing and Waterproofing
Manua= l, Specification Plate No. 32 - NAGA,
Diagr= am A.
2. Insulated-Deck Asphalt/Glass-F= iber/Aggregate
a. General: Provide built-up aggregate-surfaced
roof system with asphalt bitumen, and plies
glass= -fiber mats for lay-up as indicated.
b. Primer: asphalt cut-back primer, complying
with ASTM D41.
c. Ply Felts: 4 plies of asphalt-impregnated
glass= -fiber mats, complying with ASTM D2178,
d. Bitumen: Roofing asphalt, complying with ASTM
D312, Type III.
e. Comply with NRCA Roofing and Waterproofing
Manua= l, Specification Plat-#42- IAGA, Diagram
G. BUR Edge/Penetration Materials:
1. Roofing Cement: Asphaltic cement; comply with ASTM
D2822. Asphaltic cement shall be reinforced with
non-asbestos fibers, imparting positive properties
equal to the asbestos fibers. The Contractor shall
submit to the Contracting Office the following
information from the roofing cement manufacturer:
Reports of laboratory performed weatherometer
tests, indicating an expected life span for the
fibrous, non-asbestos cement equal to the span for
ASTM conforming asbestos fiber cement similarly
tested; in No case shall it be less than a 15 year
span. Roof work shall not proceed until such Test
Reports are submitted.
2. Glass Fiber Fabric: 1.5-lb. (min.) sheet, of woven
glass fiber, impregnated with asphalt (ASTM D1668).
3. Coated Felt: 26-lb. Sheet, of asphalt-organic felt
coated with asphalt both faces, "No. 30 Coated
4. Lead Flashing: 4-lb. Sheet of common desilverized
5. Modified Bitumen shall be modified by the addition
of styrene-butadiene-styr= ene (SBS), reinforced. It
shall be mopped on.
H. Miscellaneous Materials:
1. Surfacing Aggregate: Clean, water-worn opaque
gravel complying with ASTM D1863.
a. Where ASTM D1863 aggregate is not available,
provi= de aggregate complying with gradation
sizes 6, 7, and 67 of ASTM D448, provided that
moist= ure content by weight is 3% or less and
aggre= gate meets other requirements of ASTM
2. Wood Member's Units: Provide wood pressure treated
with water-borne preserva= tives for above ground use
3. Insulation Joint Tape: 6" or 8" wide coated glass
4. Mastic Sealant: Polysiobutylene (plain or
bituminous modified), nonhardening, nonmigrating,
nonskinning and nondrying= .
5. Asphaltic Primer: Comply with ASTM D41.
6. Fasteners: Provide industry-st= andard types of
mechanical fasteners for BUR system work, tested by
manufacturer for required pull-out strength where
applicable and compatible with deck type and
roofing products used. Provide either 1" diameter
nail heads or 1-3/8" diameter x 30-gauge sheet
metal caps for nails used to secure base sheets,
felts, or insulation boards of roofing system.
Material shall be galvani= zed or stainless steel.
2.03 FABRICATION OF SHEET METAL ACCESSORIES:
A. SMACNA and NRCA Details: Conform work with details shown,
and with applicable fabrication requirem= ents of
"Architectural Sheet Metal Manual&q= uot; by SMACNA. Comply with
installation details of "Roofing and Waterproofing
Manual" by NRCA and Section 07600.<= br>
B. Prefabricate units as indicated, or provide standa= rd
manufactured units complying with requir= ements; fabricate
from sheet metal indicated or, if not otherwise
indicated, from copper.
C. Provide 4" wide flanges for setting on BUR membrane with
concealment by composition stripping as per General Notes
on the Drawings.
D. Fabricate work with stitch riveted soldered joints and
seams; except where joint movement is necessary, provide
1-inch-deep interlocking hooked flanged filled with
E. Fabricate gravel "rings" and aggregate divider strips
with 1" high standing leg of folded sheet metal, notched
form top with 5/8" V notches. Space notches 3" o.c. where
strip intersects flow of water on roof. Fabricate rings
to sizes and shaped indicated (but not less than 36"
F. Fabricate penetration sleeves with minimum 8" high stack,
of diameter 1" larger than penetrat= ing element. Counter
flashing is specified as work of another section of these
A. Verification of Conditions:
1. Examine substrate surfaces to receive built-up
roofing system and associ= ated work and conditions
under which roofing will be installed. Do not
proceed with roofing until unsatisfactory
conditions have been corrected in a manner
acceptable to Installer.<= br>
2. Verify that deck is securely fastened with No
projecting fasteners and with No adjacent units in
excess of 1/16" out of plane.
B. Condition of Surfaces: Decks to which roofing system is
to be applied shall be sound and dry, clean, smooth and
free from projections. Application of roof system
components shall not progress when there is ice, frost,
surface moisture, or dampness, visible on the roof deck.
Joints in deck shall be sealed as necess= ary to prevent
drippage of bitumen into the building or down the
exterior walls. Deck shall be thoroughly broomed clean,
including within flutes.
A. General: This work includes, without limitat= ion, removal
of existing roofing, insulation, flashin= gs, wood blocking
and equipment pads in areas shown on the drawings.
1. Any exposed surface of the precast concrete units
shall be dried of water and cleaned of loose
2. Any disintegrating, wet or failed material shall be
3. Any cracks, minor holes, or other surface
imperfections of the precast concrete units
supporting surface shall be repaired as per
Drawings General Notes.
4. Removed roofing, insulation, and flashing will be
removed from the roof immediately without allowing
accumulation of piles of trash. Tossing of any
trash, tools or any objec= ts from roof to any areas
below, including from one roof level to another, is
5. Removed materials shall become the property of
Contractor and shall be removed from the site.
Debris and scrap shall be removed from the work
B. Protection: Protect other work from spillage of built-up
roofing materials, and prevent liquid materials from
entering or clogging drains and conducto= rs.
Replace/restore other work damaged by installation of
built-up roofing system work.
C. Surface Preparation: Before any tearoff of the existing
BUR systems, remove all gravel with a mechanical broom
and a mechanical vacuum.
3.03 ERECTION, INSTALLATION, APPLICATION
A. Fire and Wind Resistance Compliance: Install BUR system
for compliance with the following:
1. Factory Mutual requirements for "Class I" or
"Noncombustible,&quo= t; including zoned wind resistance
as specified by FM.
2. Underwriter's Laboratories "Fire Classified" and
"Class 60" wind uplift resistance.
B. Coordinate the installation of insulation, roofing=
sheets, flashings, stripping, coatings and surfacings, so
that insulation and felts are not exposed to
precipitation nor exposed overnight. Provide cut-offs at
end of each day's work. To cover exposed felts and
insulation with a course of coated felt with joints and
edges sealed with roofing cement. Remove cut-offs
immediately before resuming work. Glaze coat installed
ply-sheet courses at end of each day's work where final
surfacing has not been installed.
C. Asphalt Bitumen Heating: Heat and apply bitumen in
accordance with equiviscous temperature method ("EVT
Method") as recommended by NRCA. Do not raise temperature
above minimum normal fluid-holding tempe= rature necessary
to attain EVT (+25 F or 40 C at point of application)
more than one hour prior to time of application. Discard
bitumen which has been held at temperatu= re exceeding
finished blowing temperature (FBT)for a period exceeding
three hours. Determine flash point, finished blowing
temperature and EVT of bitumen, either by information
from bitumen producer or by suitable tests, and determine
maximum fire-safe handling temperature and do not exceed
that temperature in heating bitumen; but in No case heat
bitumen to a temperature higher than 25 F (14 C) below
flash point. For aggregate-surfaced pour coats of
bitumen, limit application temperature to minimum
required for proper embedment of aggrega= te and maximum
which will permit retention of a coating of weight
required (depends on slope of surface). Keep kettle lid
closed except when adding bitumen.
1. Contractor shall maintain not less than 2 testing
thermometers similar to Aeroil dip bimetallic type
with a dome faced gauge registering 50 F at the
kettle site at all times. Built-in asphalt heating
plant thermometers shall not be used in lieu of
2. Heating of Bitumen:
a. Solid bitumen shall be broken open on a clean