Historic Preservation - Technical Procedures
Removing And Replacing Built-Up Roofing Using Cold-Applied Mastics
Federal Bldg & Uspo/Spokane, Wa - Gsa/Pbs
Thermal And Moisture Protection
Cold Applied Bituminous Roofing
Removing And Replacing Built-Up Roofing Using Cold-Applied Mastics
REMOVING & REPLACING BUILT-UP ROOFING USING COLD-APPLIED MASTICS
A. This procedure provides guidance on removing and
installing a cold process built-up roof. This includes
work for the following:
1. Removing an existing built-up roof, insulation,
cants and flashings to the deck or substrate.
2. Priming concrete decks where applicable.
3. Loose laying vapor barrier on new metal decks where
4. Installing cricketing and field-tapered insulation
as required, except where no rigid insulation is to
5. As applicable, mechanically fastening new
insulation at metal decks, or priming deck and hot
mopping at concrete deck areas.
6. Installing specified cold process roof system over
substrate as required.
7. Installing pitch pockets as required.
8. Installing sheet lead at all drains (4 lb. lead
9. Installing new lead vent stack flashings (materials
furnished by others but installed herein).
10. Installing base flashings at all walls and
11. Installing traffic topping at areas where required.
12. Installing a surface mounted reglet flashing as
B. 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 Precautions
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. Cold-process membrane assembly shall be evaluated under
the following applicable standards of the American
Society for Testing and Materials (ASTM), 100 Barr Drive,
West Conshohocken, PA 19428, (610) 832-9585 or FAX (610)
1. ASTM D2523 load-strain properties of roofing
1.03 SYSTEM DESCRIPTION
A. Roof surfaces shall be sound, clean and dry, reasonably
smooth and free from loose and foreign material and from
depressions that would interfere with proper drainage.
A. Product Data: Prior to the application of any roofing
materials, the roofing contractor shall submit to the
Government the materials manufacturer's literature and
descriptive information applying to the materials
proposed for this project. A letter shall be furnished
from the material manufacturer indicating that all
materials used on this project conform to their
respective ASTM specification. A conformation letter
from a supplier will NOT be acceptable. Under no
circumstances shall the contractor start work prior to
1.05 QUALITY ASSURANCE
1. The roofing contractor shall be certified bondable
or guaranteeable by the roofing manufacturer. The
applicators shall have at least three years
experience in applying the specified system.
2. Applicator shall be qualified under the
manufacturer's guaranteed roof systems program.
3. Manufacturer Representative's Responsibilities
a. Rendering any inspection services the RHPO or
designated representative may request.
b. Calling to the attention of the contractor
those matters observed which he considers to
be in violation of the contract requirements.
c. Reporting to the RHPO or designated
representative in writing any failure or
refusal of the contractor to correct
unacceptable practices called to his
d. Confirming, after completion of the work and
based on his observations and test, that he
has observed no application and procedures in
conflict with the specifications, other than
those that may have been previously reported.
Final payment will not be released until this
confirmation has been received by the RHPO.
e. The presence and activities of the material
manufacturer's field representative shall in
no way relieve the contractor of his
contractual responsibilities. In the event of
a dispute, the RHPO or designated
representative shall have final authority.
4. Bidders are required to visit the site to ascertain
the local conditions readily determined by field
inspection and inquire such as location,
contractor's access area, general character of the
site, and compare the plans and specifications with
the field conditions. Failure to visit the site
will in no way relieve the contractor from
furnishing any materials or performing any work
required to complete the project in accordance with
the specifications without any additional cost to
the Federal Government.
B. Regulatory Requirements: Comply with fire, safety and
environmental protection regulations.
C. Pre-installation Conference: A preconstruction
conference will be held at which time the contractor will
be given notice to proceed. At this time the contractor
shall submit all literature and samples required
throughout the specifications for the installation of the
vapor retarder, roof insulation, and roofing system. The
contractor and the job site superintendent shall attend
1.06 DELIVERY, STORAGE AND HANDLING
A. Packing and Shipping:
1. Deliver material in manufacturer's original,
unopened containers with manufacturer's labels
intact and legible.
2. Deliver enough material to allow continuous work.
B. Acceptance at Site: Immediately remove and dispose of
C. Storage and Protection:
1. Store rolls of felt, cartons of asphalt and cans
and drums of cements, primers and coatings on end.
2. Store materials on clean, raised platforms.
3. Store and handle materials to protect them from:
a. Moisture, whether due to rain, snow or
b. Damage by construction traffic.
c. Direct sunlight.
d. Mud, dust, sand, oil, grease and dirt.
4. Select and operate material handling equipment and
store materials to keep from damaging existing
construction or applied roofing.
1.07 PROJECT/SITE CONDITIONS
A. Environmental requirements:
1. Apply all roofing in dry weather.
2. Do not apply roofing when ambient temperature is
below 40 degrees F. or when wind speed is over 30
1. Avoid heavy traffic on the work during all phases
2. Replace or restore to original condition any
materials or work damaged during construction.
3. Protect paving and building walls adjacent to
hoists, kettles and dumpsters.
4. Lap protective material at least 6".
5. Vent plastic sheets, if used, to keep moisture from
condensing and collecting on covered surfaces.
6. Secure protective coverings against wind.
7. Leave protective covering in place until roofing
work is complete.
8. Protect existing rooftop equipment against dust and
debris entry. Coordinate shutdown with RHPO.
A. Work as specified under this specification shall be
covered under the manufacturer's five (5) year guarantee
3735 Green Road
Beachwood, OH 44122
A. General: Roofing components including, but not limited
to, cold process adhesives, elastomeric flashings,
reinforcement fabrics, felts, and mats, mastics, and
sealants shall originate from single-source manufacturer
consistent with the manufacturer's warranty requirements.
Roofing ply sheets, rigid insulation, cover board, and
roofing asphalt (for required hot mopping) meeting
criteria specified herein may originate from any source.
B. Asbestos: Products containing asbestos are prohibited on
the project. All roofing materials shall be completely
C. Cold process roof system materials that may be
incorporated in the work include, but are not limited to
1. Tremco Burmastic Adhesive, or approved equal.
2. Tremco Tremlastic, or approved equal.
3. Tremco Double Duty Aluminum, or approved equal.
4. Tremco ELS Mastic, or approved equal.
5. Tremco Polyroof Elastomer, or approved equal.
6. Tremco 6" Burmesh, or approved equal.
7. Reglet Joint Sealant, as approved by system
8. Tremco TremPrime Q.D. Roof Primer, or approved
9. Tremco Tremply Hypalon Base Flashing, or approved
10. Tremco Sheeting Bond, or approved equal.
11. Traffic Topping: Rubberized material approved by
system manufacturer for heavy foot traffic.
12. Non-Shrink Grout, as approved by system
13. Reglet Primer, as approved by system manufacturer.
14. Reglet Cleaner, as approved by system manufacturer.
15. Sealant Tape, as approved by system manufacturer.
D. Ply Felts
1. Buildex Roofgrip with 3" plate
2. Dekfast with 3" plate
3. Fabco with 3" plate
F. Vapor Retarder for New Metal Decking: Laminated foil
scrim, poly sheet with a maximum flame spread rating of
5 (both surfaces) by U.L. classification. Perm rating
shall be .02 or less. Provide accessory tape with same
flame spread for joints.
G. Thermal Insulation: Polyisocyanurate Foam Board
Insulation: Rigid boards of minimum 2.0 lb./cu. ft.
density polyisocyanurate based foam core, permanently
bonded to roofing felt facer sheets. Provide in 3"
thickness, with minimum aged K-value of 0.17.
H. Cover Board: 1/2" thick six-side asphalt coated fiber
I. Cants: Fiber type, 3" minimum vertical rise.
J. Cricketing Material: Perlite Board Roof Insulation:
Rigid, noncombustible, perlite/fiber boards of
thicknesses indicated, with k-value of 0.36 at 75 degrees
F. (24 degrees C.), integrally skinned surfaces,
complying with ASTM C 728. Provide in manufacturer's
standard sizes. Note: at contractor option, factory
tapered perlite board may be furnished.
K. Coating at Existing Sheet Metal Roofs:
1. Tremco Tremlastic, or approved equal.
2. Primer: as approved by manufacturer for coating
A. Protection: A skilled, experienced foreman will be on
the job at all times during the installation of the
1. The roofing contractor shall remove the existing
roofing through the use of enclosed trash chutes or
large bucket type containers. No debris or trash
shall be thrown from the roof edge. Any damage
resulting to exterior walls as result of the
roofing operation shall be fully repaired to the
satisfaction of the Government Representative.
2. The contractor shall NOT remove more roofing than
can be adequately covered and waterproofed on the
same day. It is the contractors responsibility to
keep the roof in a waterproof condition at all
times throughout the life of this contract.
3. The contractor shall NOT pile or store debris on
the roof surface. All removed roofing shall be
discarded on a daily basis.
4. Every precaution shall be taken to keep moisture
out of the roofing during its application. Felts,
insulation and gravel shall be completely dry when
laid. No part of the roofing materials shall be
applied or laid during damp or rainy weather, or
while moisture of any kind is present in visible
amounts on the surface to be covered. Roof
insulation or roofing felts that become wet from
any cause during the progress of the work shall be
removed from the job site in its entirety.
B. Surface Preparation:
1. Apply temporary waterstops consisting of two plies
of felts and moppings of asphalt at the end of each
days work over the exposed edges of insulation and
2. Remove these temporary measures prior to the
resumption of any additional work.
3. The contractor shall notify the Contracting Officer
seven working days before any demolition on roofing
work is started. Roofing shall not be placed until
such work has been inspected and permission given
by the Government Representative. The Government
Representative shall inspect all roofing as it is
3.02 ERECTION, INSTALLATION, APPLICATION
NOTE: ROOFING TO BE LAID IN STRICT ACCORDANCE WITH
MANUFACTURER'S CURRENT PUBLISHED SPECIFICATIONS FOR ROOF
DECKING MATERIALS INDICATED, AND ROOF DECK MUST BE DRY, SMOOTH
A. Phased application of the roofing materials (layer by
layer, over several days) SHALL NOT BE DONE. Work only
on an area which can be completely roofed (up to
protective coating) in a single working day. At edges of
new work, each successive layer shall leave some of the
previous layer exposed for covering the next day. Before
the next day's work is begun, all dust, debris, bird
droppings and moisture which has accumulated during the
night shall be completely removed from the exposed edges
before new material is added.
B. Tear Off and Removal:
1. Progressively remove the existing built-up roof
membrane and insulation down to the deck by the use
of hand tools or other means approved by
authorities having jurisdiction for removal of
existing materials containing asbestos fibers.
Verify and comply with requirements imposed by
regulatory agencies. Transfer all debris off site
to an appropriate landfill. Pay all landfill
2. Similarly remove base flashings from all perimeter
vertical surfaces. Leave all such surfaces
sufficiently smooth to receive new base flashings,
fully and adequately bonded. DO NOT use
sandblasting or other abrasive means to remove
3. Where indicated to remain unreplaced, remove and
clean all drainage fittings, clamp rings, sumps and
etc., on drains and store for later reinstallation.
Plug drains to prevent debris entry. Discard old
4. Where necessary for proper installation of base
flashings and equipment curbs, slit the corners of
the sheet metal covers and vents and bend up sides
which counterflash roof base flashings sufficiently
to allow for the roofing work.
C. Decking: After all the built-up roofing, insulation,
etc. has been removed, the deck shall be thoroughly
inspected for traces of deterioration. If deck damage is
present, repair or replace with the RHPO's approval
before proceeding. (Cost of deck repair will be paid on
a change order basis as a concealed condition).
D. Vapor Retarder (at new metal decks only): Install loose
laid on deck just ahead of insulation. Lap all joints 2"
minimum and tape joints with flame spread rated accessory
foil scrim tape. Extend to top of cants. Cover retarder
with insulation board or cricketing layer(s) and
mechanically fasten board as specified elsewhere.
Install mechanical fasteners in insulation board or
cricketing layer(s) having minimum 1-1/2" thickness.
E. Wood Nailers:
1. Install treated wood nailers at all perimeter metal
edge flashings, metal flanges of roof top
equipment, pitch pockets, vent stack leads and
equipment support legs.
2. Nailer should be equal in thickness to the
1. Installation at Metal Decks:
a. Mechanically fasten the approved insulation to
the deck utilizing one of the approved fasteners.
b. Fasteners shall be installed at a rate of one
per every two (2) square feet of board.
2. Installation at Concrete Decks:
a. Prime concrete deck with one gallon primer per
100 sq. ft.
b. Install the approved insulation to the deck in
a uniform application of Type III hot asphalt
at a rate of 30 lbs. per 100 sq. ft.
c. "Walking in" the insulation boards is required
to assure good contact and uniform adhesion.
3. Cover Board: Install over insulation as top layer.
Use mechanical fasteners at metal deck. Hot mop
with Type III hot asphalt, 30 lbs. per 100 sq. ft.,
at concrete decks.
4. Insulation General:
a. The insulation should be tightly butted
together with the joints staggered. Offset
joints from any substrate plywood joints.
b. Installed insulation shall not be left exposed
to the weather. It shall be covered and
waterproofed at once. All exposed edges left
at the end of the day's work shall be
temporarily sealed. Remove the cut-offs as
5. Crickets and Tapered Insulation:
a. At the areas indicated, install new crickets
to facilitate positive drainage.
b. Crickets shall be constructed of layers of
perlite set in Type III hot asphalt.
c. Prior to installing the approved insulation,
prime the cricket with manufacturer's
recommended primer at a rate of one gallon per
100 sq. ft., then set insulation board in Type
III hot asphalt at a rate of 40 lbs. per 100
G. Cold Process Built-Up Roof Insulation:
1. All felts shall be rolled onto the roof surface,
cut in 18' lengths and allowed to relax in the hot
sun a minimum of 30 minutes. (Felts shall be
allowed to relax for longer periods of time on
2. Starting at the point of the roof, apply over the
insulation a uniform coating of cold process
adhesive at a rate of 3 gallons per 100 sq. ft.
3. Embed into the cold process adhesive a 12", 24" and
36" wide strip of roofing felt. Overlap the 12"
wide felt completely with the 24" and overlap this
with the 36" wide roofing felt. Continue to
install full widths of felt, overlapping the
preceding felt by 25" in shingle fashion.
4. Over all end laps, fully embed into the cold
process adhesive one full ply of roofing felt, to
hold down end curls, running perpendicular to the
5. Felts will be extended their full length and lapped
4" creating a continuous joint at the felt ends.
6. Each ply of felt including the starting felt shall
be solidly coated the full width with at least
three gallons per square and nowhere shall felt
touch felt. The felt shall be broomed to assure
complete contact without wrinkles, fishmouths or
7. Extend all plies to the edge of the roof or to the
top of cant strips and cut off evenly.
8. Temporary water stops shall be installed at the
completion of the day's work and removed before
starting installation of the membrane the following
work day. No unfinished roofing shall be left
9. Prior to the application of the top coating, all
fishmouths shall be cut and reinforced with roofing
felt and cold process adhesive. All ridges shall
be cut and repaired with a 12", 24" and 36" ply of
H. Base Flashings:
1. Extend all roofing plies over the cant strip and
cut off evenly.
2. Apply sheeting bond 1/8" thick to the entire wall,
cant strip, and onto the roof surface 6".
3. Install hypalon base flashing.
4. Sheeting shall be of sufficient width to cover the
wall and extend onto the roof 4" beyond the lower
edge of the cant except where reglet conditions are
5. Secure the hypalon sheeting to the outside edge of
the wood nailers (when provided) on the parapet
walls and the top of the equipment curbs 8" on
center with Simplex 1" square head roofing nails.
6. Install metal copings, surface mounted reglets and
counterflashings at the areas indicated to cover
and secure all exposed fasteners.
7. Seal all exposed vertical edges of base flashing
with a 1/8" x 1" galvanized closure bar. Apply
tape to wall; apply hypalon to tape; apply another
layer of tape; apply closure bar to tape and fasten
with fasteners at 6" on center.
8. Seal the lower edge of the hypalon sheet with a
three course application of Polyroof and 6"
9. Splice all hypalon laps with sheeting bond and
three course with Polyroof and Burmesh.
I. Metal Roof Flanges - perimeter metal edge, vent stacks,
equipment pitch pockets, etc.
1. Under all metal roof flanges install wood nailers
of equal thickness to the insulation.
2. Set all roof flanges on top of the roofing plies
and in a bed of ELS mastic.
3. Apply Polyroof between all metal edge lap joints.
4. Nail the flange to the wood nailers with large head
roofing nails 3" on center maximum.
5. Prime with approved primer.
6. Seal all flanges with a 5 course application of ELS
mastic and 4" and 6" Burmesh.
J. Pitch Pockets:
1. Pitch pockets shall be 24 gauge galvanized steel 3"
high with a 4" roof flange.
2. Pitch pockets shall allow for 2" of clearance
between the penetration and the pitch pocket wall.
3. Fabricate the top edge of the opening with a 1/4"-
1/2" hem bent to the outside.
4. Solder closed all four corners.
5. If the pitch pocket is used around an existing
penetration and cannot be slipped over, then make
it soldered or pop riveted.
6. The pitch pocket is installed over the roofing
plies and set in a bed of ELS mastic nailed
securely to the wood nailer which is under the
flange, using large head roofing nails 3" on
7. Prime flanges with approved primer.
8. The roof flange is 5 coursed with ELS mastic and 4"
and 6" Burmesh.
9. Fill the pitch pocket 2" with non-shrink grout.
10. Fill the pitch pocket with Polyroof so that the
water will shed off the top.
11. Clean the pitch pocket interior with primer.
K. Drains (both new and re-used existing drains):
1. Remove and lift drainage fitting clamps, rings,
etc. on drains. Clean and store for later
2. Taper insulation to create a 48" x 48" sump around
3. Plug drains to prevent debris entry.
4. Apply two layers of 1" caulking tape to the drain
5. Install all roofing plies into the drain bowl.
6. Discard existing lead sheets and replace with
minimum 30" square, 4 lb. lead.
7. Embed new lead in Polyroof and install on top of
plies of built-up roofing system. Extend lead 1"
beyond the clamping ring and bend down into the
8. Flash edges of lead with a 5 course of Polyroof and
L. Lead Vent Pipe Flashings: Install over the completed
plies bedded in with ELS mastic, nailed maximum 3" on
center into wood nailers which are installed under the
plies, the 5 coursed with ELS mastic and 4" and 6"
Burmesh (Burmesh is covered with 1/8" of ELS mastic to
cover green mesh).
M. Miscellaneous Flashing and Roof Top Equipment:
1. Reinstall pipe and conduit flashings, reset
ventilators on curbs and secure to match existing.
2. Where corner metal flashings were or are opened and
side of flashings bent up to allow space for
working, bend flashings back down to the original
position and fasten a prefabricated 24 gauge
a. Insert prefabricated sheet metal corners,
lapped under a minimum 2" at sides and top,
under all corners. Secure the position using
a minimum of 4 pop rivets or self-tapping
sheet metal screws.
3. Any existing flashings, drainage fittings and wood
blocks, which are damaged shall be replaced to
match the existing as part of this work.
N. Cold Process System Protective Coating:
1. Apply protective coating after all phases of the
cold process roof have been completed leaving a
watertight system with a solid smooth built-up roof
2. Allow the cold process system to cure a minimum of
3. Prior to the application of protective coating,
wash down the entire surface and allow to dry.
4. Apply coating to the roof surface and base
flashings at the rate of 4-1/2 gallons per 100 sq.
ft. Care must be taken to assure uniform coverage
and appearance. Excess piles and accumulation will
not be accepted and must be brushed out.
O. Aluminum Reflective Coating:
1. Allow the protective coating to cure a minimum of
2. Wash the roof surface and allow it to completely
3. Apply aluminum reflective coating to the roof
surface and base flashings at a rate of 150 sq. ft.
per gallon. Aluminum may be sprayed, rolled or
P. Traffic Toppings:
1. Install traffic topping at the areas indicated.
2. TremTreds (or approved other) are to be installed
in a full liberal application of roof mastic.
END OF SECTION