C05a RFI QA 1240BH26Q0029.docx

FOR OFFICIAL USE ONLY

REQUEST FOR INFORMATION (RFI) FORM

1240BH26Q0029

GAOA Mesa Falls Rec Area Retaining Wall Caribou-Targhee National Forest

RFI #1- How are the 4x4 curb and 4x10 stringers accounted for in the schedule of items?

Board feet for 4x4 curb and 4x10 stringers are included in Item Number 061533 3"x6" Pressure-Treated Wood Decking.

RFI #2 – Will the site be closed during construction.

Project site will be closed to the public. Contractors should leave the trail passing the site open.

RFI #3 – Can you quantify the amount of “Pinning” required?

Pinning refers to stone pinning. There are 20-30 small to medium sized holes in the wall that will need to be pinned with appropriately sized stones (5-60 lbs). Contactors should field verify quantities prior to bidding.

RFI #4 – Can you drive a vehicle down to the project site.

Full sized vehicles will not be allowed down the trail. A trail size ATV/UTV with a small trailer would be allowed.

RFI #5 - The specifications require historic preservation work to be performed by, or under the direct supervision of, someone meeting the Secretary of the Interior's Professional Qualification Standards for Historic Architecture and separately define a Historic Treatment Specialist as a firm with experienced personnel and a demonstrated record of similar rehabilitation work. Which standard governs the masonry restoration itself?

The Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring & Reconstructing Historic Buildings.

RFI #6 - Site inspection of the riverside face found numerous voids and gaps between stones without mortar, some appearing original to the historic construction and others where stone has clearly shifted or is missing, and the talus slope the wall is built into continues below and beyond the wall's constructed height. Sheet C2 directs replacement of missing or shifted pinning stone but does not define what constitutes a void requiring pinning or how far down the back face that requirement extends. Is pinning required only where stone has visibly shifted or is structurally loose, and does the required scope end at the wall's structural face or continue into the surrounding natural slope?

Pinning is required only where stone has visibly shifted or is structurally loose. The required scope ends at the wall's structural face.

RFI #7 - Fabrication of the basalt wall cap requires splitting individual stones by hand, with no saw or grinder marks permitted in the finished work, to a specified thickness of 4 to 6 inches. Site inspection found the on-site talus consists of large, irregular columnar basalt chunks that do not split to a predictable, uniform plane. Will occasional pieces that fall slightly outside the specified thickness range, but are otherwise sound and consistent with the surrounding cap, be accepted, or must every piece be reworked by hand until it falls within 4 to 6 inches?

Stone should be worked to fall within the specified 4-6” range.

RFI #8 - The site plan shows a paved path connecting the parking lot to the existing rock wall, with no route or width shown for vehicle or equipment access. May a vehicle be driven from the parking area to the work site, and if so, along what route?

See RFI #4.

RFI #9 - Closing the overlook to public access during construction, while keeping the adjacent path open, was discussed at the site visit. Please confirm in writing that the contractor may close the overlook itself to the public for the duration of the work, provided the adjacent path remains open.

See RFI #2.

RFI #10 - Site inspection on August 20, 2026 found significant public and tourist traffic at the overlook, and working the wall face with the public present during active construction is not workable from a safety standpoint. Combined with the 60 calendar day performance period and Section 013591's restriction on exterior wet work below 40 degrees Fahrenheit and cleaning below 45 degrees Fahrenheit, what notice to proceed window is anticipated?

We anticipate work starting mid-September. If weather prevents the work from being completed we will go into winter exclusion and complete the work next spring/summer.

RFI #11 – Existing Wall Material: Can you briefly describe the existing retaining wall material (e.g., concrete block, stone masonry, poured concrete) to assist in sub-selection and pricing?

As shown in the pictures and described in the plans and specifications, the wall is constructed in the random rubble style of stone masonry, using two types of stone: lava rubble (volcanic tuff) and columnar basalt.