178003A_BIDOW-MainHouseSLATEROOF5.15.2015.pdf

Cane River Creole National Historical Park Department of the Interior

National Park Service

Natchitoches Parish, LA

MAIN HOUSE

NEW SLATE ROOF

Oakland Plantation

(PMIS 178003A)

BID-ITEM DESCRIPTION OF WORK

Prepared by Eric Z. Ford

Date: 5/15/2015

This view of the Main House east elevation shows the uniquely different north and south sloped of the roof. This project has an asymmetric roof meaning all elevations have a different slope rise-to-run ratio. The roof and minor repairs in-situ occurred when the roof was rehabilitated in 2005 after the last occupants, who last modified the roof in the 1950’s, sold the property to the National Park Service in the 1990’s. Since reproduction of the existing roof shingle is not feasible, the house roof will return to an earlier material, slate, with the benefit of modern building codes and design to correct all deficiencies.

BID ITEM DESCRIPTION OF WORK CARI - 2

178003A – MAIN HOUSE NEW SLATE ROOF PROJECT

INTRODUCTION

LCS # 91620

STRUCTURE # HS-O-12

FMSS # 49129

ACCOUNT # PH.P0178003A.00.1

PMIS # 178003

PEPC # 44767

The Oakland Plantation Main House was completed in 1821 with the third (3rd) circa 1950’s asbestos roof in-situ that has reached the point where it is due for cyclic replacement. The roofing shingles continued to be displaced including the shingles reinstalled with clips during the 2005 rehabilitation of the house. The original fasteners are detaching from the shingles due to expanding nail holes and deteriorated nails. The roof decking requires close inspection, repairs, or replacement as the later c. 2005 repairs have not proven to be a long term solution.

Our Main House asbestos shingle roof, like many of our historic structures, has a vernacular and unique method of installation that exhibits a strong visible horizontal course when viewing the roof. The shingles butt ends are placed tightly together to make the vertical joint in every course appear almost invisible, which place more emphasis on the horizontal "thatch pattern" line. The existing shingles are believed to be Johns Manville production of J-M American Colonial Asbestos Shingles with an overall measurement taken, from shingles stored under the house, at 30” wide by 14” high by 5/32 thickness (not exposed) 3/32” thickness (weathered exposure).

The shingles have a wood grain (Cedargrain) surface pattern with remnants of a grey coating that was applied.

The shingles were both factory cut and likely field cut with a custom off-center taper to have a steeper pediment top, for installation to the steep roof elevations, and maintaining an equal height on the butt end, which varies with the cut. This steeper pediment field cut leaves evidence with broken edges while the factor cut shingles show not broken edges. This was observed from several samples stored under the house. The shingles provided an exposure of six inches (6”) in-situ; and the pediment cut prevented fasteners from penetrating the shingle course below, which is typical for roof installations.

The roof pitch of the Main House is different on all elevations, which may further explain the need for the custom taper cut of the shingles. The roof pitch rise/run, to be field verified, per elevation is as follows:

North Elevation Slope - 16.75/12 East Elevation Slope - 7.25/12 South Elevation Slope – 14.63/12 West Elevation Slope – 5.75/12

SUMMARY

The Bid Item Description of Work is a summary of the Scope of Work (SOW), which is included, for the replacement of the Main House asbestos roof shingles along with other repairs to provide a structurally sound and sustainable new slate roof. In summary, this phase of the SOW shall cover the specific listed items #2 thru #7 and other work that may be required upon execution. The work that is required and other reference information in the SOW is provided to give the scale and complexity of the roof project. The listed items represent the bid items for this contract, which this is the third and final contract:

BID Items Work Order # Description 0 9306963 P - Demo Shingle from Main House Roof 1 9307116 P – Structural Assessment and Upgrade 2 9309275 P - Disposal of Materials 3 9307116 P - Repair Roof Decking As Needed In-Kind

BID ITEM DESCRIPTION OF WORK CARI - 3

4 9307493 P - Correct Drainage around Roof Hatch at Other Penetrations 5 9307412 P - Install Underlayments (Felt, EPDM) and Related Work 6 9307027 P – Slate Purchase and Shipment to the Project Site 7 999097 P - Replace Existing Shingles with New Slate Roofing Shingles

The NPS attempts to coordinate this project with all three contractors (Asbestos Abatement Planner, Asbestos Remediation Contractor, and Slate Roofer Contractor) to make the process seamless and mutually beneficial.

PRESERVATION/WORK EXECUTION

Demo Roof Shingles/Salvage by Certified Contractor per State of Louisiana Requirements -Approximately 8,800 sqft. (88 squares)

NOT IN CONTRACT

Structural Assessment and Upgrade (BID ITEM #1) -Although the roof prior to the asbestos shingle was slate material 3/16-inch to 1/4-inch, and structural modification occurred to the foundation and attic framing a structural assessment is required.

-Provide structural assessment by a structural-preservation engineer as required per the SOW.

-Supplemental 2x6”framing and accessories between spans greater than 16” o.c. per the attached drawing. The engineer’s sensitive recommendations are the final treatment that must be implemented.

-Contractor shall price at a minimum the supplemental framing and accessories and the consultation costs.

Provide the consultation information as required stamped by the engineer.

Disposal of Materials (BID ITEM #2) -Dispose of approximately 8,800 sqft of felt paper. Shingles and original felt will be removed by an asbestos contractor under separate contract. Coordinate as to prevent redundancy of roof covering.

-Before the next phase (underlayment/roof finish) of work begins all required LDEQ inspections and LDEQ documentations shall be completed, received, and accepted by the Park.

-The next phase of work is not authorized to start until notified by the NPS or Park representative to proceed. Also this is the contractor lead time to procure and deliver slate to the job site.

-Dispose of all flashing deemed not acceptable and/or meeting the material type specified.

-Dispose or recycle construction related debris.

-Copies of all disposal manifestos must be submitted to the park providing all required info including the weight per each load removed, landfill location, etc.

Repair Roof Decking (sheathing boards) as Needed In-Kind (BID ITEM #3) -This phase of the roof work shall not commence until all requirements for the removal and disposal of the asbestos material is approved as satisfactory per LDEQ.

-The newly install #15 lb felt paper, temporary cover, should be maintained/replaced as needed to maintain a watertight system until the final roof covering system is ready for installation.

-Upon notice to proceed, ensure roof is protected at all times during work prohibiting water infiltration - utilizing tarp, etc.

-Remove the temporary felt paper and inspect the roof superstructure (decking, rafters, and sills).

-Replace and/or repair with epoxy any deteriorated roof spaced or tongue and groove sheathing boards - estimate 1,200 sqft. Field Verify. This include filling in voids/gaps larger than 1-1/2” as can be seen on the north/south sheathing.

-Replace all eave sheathing boards that are punkie to the touch or with slight pressure using a tool or that may presently be wet/damp.

BID ITEM DESCRIPTION OF WORK CARI - 4

-Apply the same type of finish (white) as removed boards utilizing Sherwin Williams “Duration” paint (3 coat application). Work with the Park on the specific finish type and color.

-Credit: If less than the material requiring replacement is warranted then a credit would be the wrap the eave boards, especially at the gutter between the Kitchen Ell and Main Roof. Other areas may need this treatment.

-The Contractor will document with the Park representative the areas that require repair or replacement.

-Some structural repairs may be required, especially at the ridges or at roof penetrations – estimate 600 sqft (chimney, etc.). Field Verify. The NPS representative will authorize any structural field-repairs recommended and approved them through the submittal process utilizing the NPS form CM-16.

-Replacement decking shall be in-kind having the same texture; thickness (4/4"); widths (1x6”, 1x7”, 1x8”, and 1x12”); cut pattern (square-edge boards or T&G); and species (cypress, field verify) or approved equal, Red Oak No. 1C or better. All new material shall be date stamped on the roof finish side (exterior) then inspected prior to installation. The date stamp shall be clearly written with a permanent marker at a height measuring two

(2) inches with the following information, 'CARI XXXX' where XXXX represents the year of installation.

-There shall be no nomenclature used for epoxy repairs.

Correct Drainage at Roof Hatch and at Other Roof Penetrations (BID ITEM #4) -The extant hatch is approximately two (2) to three (3) inches above the roof (field verify) and shall be raised higher above the roof but not to exceed six (6) inches to eight (8) inches in height. The height shall be determined to adequately shed water around the hatch opening during moderate to heavy rainfall. An upslope cricket flashing may not work for the extant hatch height.

-Install an upslope cricket or diverter with flashing from the hatch penetration towards the ridge, which shall provide better rain water distribution than what exist presently.

-The minimum treatment requires installation of an EPDM up sides and around the roof hatch and cricket once shingles are removed. Assume 10 sqft of roof system will be impacted by this activity. Field Verify.

-Install an upslope cricket with flashing to each of the three (3) chimneys.

-Utilized lead-coated cooper flashing unless directed to replace inadequate flashing. The base flashing shall be replaced or supplemented with new lead-coated cooper base flashing according to the new cricket height. Refer to ‘CARI 102 Section 07600 Specification. Field verify.

-Install underlayment including EPDM (full size) with proper overlap not less than (NLT) six (6) inches.

-The three (3) brick chimneys were partially repointed during the circa 2005 renovation of the Main House.

Inspect all chimneys with Park representative to make determination if repointing is required as the soft brick and mortar may be source of water infiltration.

-Repoint chimneys with approved lime-based mortars. Rake all existing mortar joints and tuck point (repointing) to match the historic configuration/profile.

Alternative: Apply a lime rendering or lime-based parging to surface of chimneys to address water infiltration through the brick masonry. No Sealer shall be used on this project.

- Use approved Park mortar/stucco mix - mixing will be in presence of Park representative to ensure lime-based mortar is used. Submit material for approval.

Install Roof Underlayments and Related Work (BID ITEM #5) -Install underlayments as follows covering the entire roof:

#30 felt paper medically attached to decking; Ethylene Propylene Diene Membrane (EPDM) adhered to the felt and possibly back nailed (follow manufactures recommendations); and Slip sheet (as needed).

-Replace approximately 8,800 sqft. (88 square) underlayment material with new #30 lb felt paper and install per manufacture’s recommendations.

-Install rosin paper (slip sheet) per manufacture’s recommendations according to the National Roofing Contractors Association (NRCA) standards.

BID ITEM DESCRIPTION OF WORK CARI - 5

-Replace flashing at gully, eaves, valley, gable louvers, chimneys, ridges, and other roof penetrations with lead-coated copper if not one of these two material types in-situ. All galvanized, aluminum, or other flashing shall be replaced.

-Install new lead coated copper flashing, correctly, over EPDM (final underlayment material). .

-Replace all half octagonal gutters and downspouts (this was specified in 2005) with lead-coated copper including new interior gutter strainers, gutter screen head, and accessories. Reinstall plastic leaders at bottom of gutters.

Alternative: Clean all galvanized gutters and downspouts. Repair gutters and remove c. 2005 delaminating interior gutter finish and reapply after treatment of oxidized areas. Sand oxidized surfaces, apply rust converter, and rust inhibitor primer before apply gutter coating system. -Replace any missing gutter strainers at each droplet for the downspouts.

-Remove and Prep the gable end louvers (north and south elevations) by wire brushing and sanding all oxidized surfaces. Apply rust converter and two (2) coats rust inhibitor primer; allow drying between coats. Paint with a galvanized paint finish – two (2) coats.

Alternative: Remove existing louvers for storage in the Park’s museum collections and replace in-kind with lead-coated cooper finish.

Slate Purchase and Shipments to the Site (BID ITEM #6) -The Contractor shall coordinate with the Park representative location and number of dumpsters to have on site as well as designated material staging area(s).

-Provide shipping manifesto for both asbestos disposal (abatement contractor) and new roofing materials noting the weight, etc.

-A. Coordinate and pay all costs to properly ship all asbestos containing material to designated landfill and/or recycling centers per LDEQ regulations.

-B. Coordinate and pay all costs for the shipping of the slate material to the project site. The Contractor’s price shall include two

(2) to three (3) full pallets of material representing each shingle type, to be given to the Park ONLY, and 10% additional material to accommodate for breakage during the execution of the roof work. Material, unbroken, left over from the job remains the property of the national park service.

Replace Existing Shingles with New Slate Roof Shingles (BID ITEM #7) -Replace approximately 8,800 sqft. (field verify) of existing asbestos shingles with new slate roof or other approved alternative roofing material as determined through the Choosing by Advantages (CBA) and Value Analysis (VA) process and compliance process.

-Prepare and submit shop drawings of each type and cut of shingles for review and approval prior to purchase of new material to include the roof shingles and dormer shingles. The dormer shingles shall be installed horizontally.

-Submit samples of the new replacement shingle material to the Park for review and approval.

-Submit MSDS sheets and warranty information.

-Install roof shingles with stainless steel nails.

-The hip ridges shall have a lead-coated copper material to match the metal ridges in the historic photo(s).

Figure 1: homebuilding.thefuntimesguide.com source

BID ITEM DESCRIPTION OF WORK CARI - 6

Other -Concluding all work, the site shall be restored to its pre-work condition. All fenced in areas are to be maintained weekly by the contractor per the Park's mowing/weeding requirement.

END BID ITEM DESCRIPTION OF WORK

REFERENCE NOTE – NO LONGER CONSIDERED:

Existing asbestos roof system is past its life cycle.

The initial planned material was the GAF Weatherside Shingles which match our shingle height. Our Johns Mansville Asbestos Roof Shingles are cut with a pitch from the top middle down to each side with equal heights.

This allow for an irregular pitch due to whether the thatch is protruding (down) or recess (up). Again, from the samples, the sides are equal heights regardless of the thatch pattern. However, our shingles are about 5" (4 13/16") longer than the replica material. Remember our roof character has a strong horizontal line presence with no emphasis on the butt joints just as it would be installed on wall. This installation method was based on the manufacturing of the material.

The manufacture would not guarantee the product warranty if used for a different application – as roof. The NPS considered a designed system to install this material but there would be not warranty if the product failed to perform as roofing shingles.

GAF website:

http://www.gaf-weatherside.com/index.html

Not a preferred alternative:

Reuse of existing shingles (exposure warned) presents a hazard and the NCPTT looked at samples under a microscope and observed the brushing the hand across the shingles released asbestos fibers. The decision was made to dispose of the shingles.

Asbestos information from LDEQ website:

http://www.deq.louisiana.gov/portal/DIVISIONS/PublicParticipationandPermitSupport/Asbestos.aspx http://www.gaf-weatherside.com/index.html http://www.deq.louisiana.gov/portal/DIVISIONS/PublicParticipationandPermitSupport/Asbestos.aspx