Supplemental Guidelnes For Repairing & Replacing Slate Roofs
- Procedure code:
- Federal Building/Us Courthouse, Eau Claire, Wi
- Thermal And Moisture Protection
- Slate Shingles
- Last Modified:
SUPPLEMENTAL GUIDELINES FOR REPAIRING AND REPLACING SLATE ROOFS
A. This procedure provides supplemental guidelines to be
used when specifying repair or replacement work on slate
roofs. Guidelines for qualification, materials,
fabrication and general guidelines for installation are
included. This procedure should be used to supplement
07315-01-R and 07315-03-R.
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.
Submit three samples of slates. Submit samples of nails,
rag felt and plastic cement.
1.03 QUALITY ASSURANCE
A. Manufacturer Qualifications: Provide primary products,
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
manufacturer of primary products for use with roofing
B. Installer Qualifications: A single Installer ("Roofer")
shall perform the work of this section; and shall be a
firm with not less than 5 years of successful experience
in installation of slate shingle roofs similar to those
required for this project and which is acceptable to or
licensed by the manufacturer of primary roofing material.
1. Installer Certification: Obtain written
certification from manufacturer certifying that
installer is approved by manufacturer for
installation 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 supervisor/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
3. Provide detailed written resume of slate
installer's qualifications including at least 5
examples of quality slate installations.
C. Pre-Application Roofing Conference: Approximately two
weeks prior to scheduled commencement of slate shingle
installation and associated work, meet at project site
with Installer, installer of each component of associated
work, other work in and around roofing which must precede
or follow roofing work, the Contracting Officer,
Government, roofing system manufacturer's representative,
and other representatives directly concerned with
performance of the work including (where applicable)
Government's insurers, test agencies, and governing
authorities. Record (Contractor) discussions 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 requirements (drawings,
specifications and other contract documents).
3. Review required submittals, both completed and yet
to be completed.
4. Review and finalize construction 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 mandatory requirement).
1.04 DELIVERY, STORAGE AND HANDLING
A. 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
B. Felt rolls and shingles 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.
1.05 PROJECT/SITE CONDITIONS
A. Weather Condition Limitations: Proceed with roofing work
only when existing and forecasted weather conditions will
permit work to be performed in accordance with
manufacturer's recommendations and warranty requirements.
B. Temporary Protection: Contractor shall be responsible 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.
A. Contractor shall submit, before installation,
certification from the producer of slate shingles that
the Contractor has undergone training in the application
of these shingles by the producer.
B. The Contractor shall provide a two-year warranty against
leaks, faulty material and workmanship.
A. Procedure 07315-02-S contains an extensive list of slate
roofing manufacturers for reference.
Reference: ASTM C406/C406M -10 Standard Specification of Roofing Slate
NOTE: See 07315-01-R or 07315-03-R for specific materials and
equipment required for slate repair and replacement. Other
general requirements relating to materials are listed below.
A. Material and Workmanship: Slate shall conform to the
1. Unless otherwise specified, surfaces shall be of
reasonably smooth cleavage.
2. Slate shall be free from knots or knurls that would
lessen the durability or weather tightness of the
3. Unless otherwise specified, slate shall be
rectangular, with straight cut edges.
4. Unless otherwise specified, corners shall be
reasonably full on exposed edges, with no broken
corners on covered ends that would diminish the
nailing strength or weather tightness.
5. Unless otherwise specified, the thickness shall be
approximately three-eighth inch.
6. Flatness - The maximum bend shall not exceed one-
eighth inch in 12 inches.
7. Unless otherwise specified, holes shall be machine-
punched for 3-inch double lap.
B. General Requirements:
1. Slate shall be whole and clean. Not more than 2
percent of broken slate will be accepted.
2. All slate shall be hard, dense, sound rock, punched
for two nails each. No cracked slate shall be used.
All exposed corners shall be practically full. No
broken corners on covered ends which sacrifice
nailing strength or the laying of a water-tight
roof will be allowed.
C. Detail Requirements:
1. Color: To match existing or original and as
approved by RHPO.
2. Strength: The average modulus of rupture across
the grain shall not be lower than 9,000 pounds per
3. Absorption: The maximum absorption shall be - ASTM Grade S1--0.08%
4. Acid Resistance: The slate shall, under the acid
test, show no softening to an average depth greater
than - ASTM Grade S1 -- 0.002 inch.
D. Methods of Sampling, Inspection and Tests:
1. The inspection of the slate may be made at the
discretion of the Government either before or after
2. Samples for test, when required, shall be selected
by the Inspector and shall be representative of the
material. At least one sample of slate shall be
selected from each carload or fraction thereof.
Additional samples may be taken for test at any
time or place at the discretion of the Government.
3. Absorption Test: The specimen shall consist of a
square or rectangular slab not less than 4 inches
on any side, cut from the slate shingle so that the
saw cut is nowhere nearer than 1 inch to the
A. Examine substrate surfaces to receive slate shingles and
associated 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.
1. Verify that flatness and fastening of wood roof
decks are securely fastened with no projecting
fasteners and with no adjacent units in excess of
1/16-inch out of plane. Pull out or drive home
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.
Deck shall be thoroughly broomed clean, including within
C. Replace any boards of the wood roof deck if shown to be
weak structurally, rotted, splintered or broken with
A. Roof removal is to commence in the center of areas to be
removed and to proceed outward to the edge of the areas
to be removed.
B. Any disintegrating, wet or failed material shall be
removed and replaced.
C. Removed roofing, insulation, flashing and masonry will be
removed from the roof immediately without allowing
accumulation of piles of trash. Tossing of any trash,
tools or any objects from roof to any areas below,
including from one roof level to another, is expressly
D. Removed materials shall become the property of Contractor
and shall be removed from the site. Debris and scrap
shall be removed from the work area daily.
E. Temporary Roof Installation:
1. If adverse weather conditions require protection of
exposed deck, install 6 mil polyethylene sheets
horizontally, shingling, from top to bottom. Staple
and tape all joints and edges.
2. Remove temporary roof completely prior to
installation of permanent roofing system.
END OF SECTION