Archive Record
Images
Metadata
Collection |
Michael Fulp House |
Archive Number |
MFHFN4 |
Title |
Foundation perimeter drain plans |
Description |
The three images in this record are the as-built plans and detail sketches of the perimeter drains and related fittings, facilities, and waterproofing materials: [A] along the northern half of the east eaves wall, the north gable wall, and the two northern segments of the west eaves wall [Image #1] [B] along the southern half of the east eaves wall, the south gable wall, and the southern 10 foot segment of the west eaves wall [Image #2] and [C] The site plan [Image #3] showing the discharge pipe and its fittings; the Mouns Jones House and the alignment of the possible future feeder line to conduct the out-flow from Mouns Jones House foundation drain pipes through the wye at "D" into the discharge line{1}, which is protected from flood backflow by the "check" valve{2} at "B." A standpipe "Tee'd" into the 4-inch solid discharge line downstream from the wye at "D" will serve as a cleanout access to break-up blockages in either direction. The pitch in the 4-inch perforated PVC collection pipes [SDR35 gauge] along the foundation is minimal, less than 1/8 inch per foot [less than a 1% slope]. The pitch in the discharge pipe is 1/4 inch per foot, or slightly more, in order to facilitate rapid outflow from the collection system. This pitch produces a total vertical drop of 30-36 inches from the building to the outlet. The backfill material along the foundation was selected for permeability to accommodate drainage into the collection system through a full-wrap non-woven geo-textile filter fabric [4.5 oz. rating], downward through the Delta Drain "dimpled" waterproofing membrane, and percolating through a clean 2B stone bed into the perforated collection pipes. This system will divert, collect, and discharge close to 90% of the water which historically had saturated and degraded the foundation mortar joints{1} [see archive record MFR10PH3--1005.01.059, showing the mortar-less joints in the sub-grade foundation walls and detailing the remediation plan for the unstable foundation under most of the building]. The collection pipes in Image #2 are connected to the capped end of the pipe in the center of the east eaves wall. The south gable wall foundation base ["soffit"] is 6-8 inches shallower than the bearing plane of the east eaves wall foundation. The predetermined pitch of the perimeter piping produces flow through all segments around the full perimeter of the building into the solid discharge pipe. Piping beginning south of the door stoop provides a continuous counter-clockwise flow along the south gable wall, northward along the east eaves wall, then southward along the west eaves wall to the solid discharge pipe westward to the outlet. The short collection pipe between the cellar entry and the stoop on the west eaves wall flows southward into a solid pipe returning at a 45-degree angle and wyes into the westbound outlet pipe. FOOTNOTES {1} Assuming that the 4-inch pipe has adequate capacity to drain the combined discharge; if not, the water collected along the foundations of both buildings will be transported away at an marginally lower discharge rate, which will still be exponentially faster than the natural percolation through relatively impervious clay beds during the past 230 years. The frequently saturated sub-grade conditions, punctuated by periodic floods from the Schuylkill River, gradually degraded the bed and joint mortar in the foundations by dissolving the lime content, leaving a disintegrated residue of soils, gravel, and lime "chunks." This loose material contributed minimal bonding, stabilizing, or bearing benefit to the masonry structure. The destabilized foundation required prompt remedial attention once these defects were observed after excavation exposed the virtually mortar-less and displaced condition of much of the foundation. The remediation plan is detailed in archive record MFR10PH3--1005.01.059. {2} The backflow valve material is Schedule 40-gauge PVC, which is adapted to the thinner SDR35 pipe-wall thickness by a reducing-ring insert. Larry Ward |
Date |
10/20/2010 thru 11/24/2010 |
Object Name |
Field Notes |
Catalog Number |
1005.01.058 |
Search Terms |
MFKFN As-built Drain Pipe Drain Trough Drainage Board Drainage Plan Foundation Drain Foundation Waterproofing Geotextile Filter Fabric |
Creator |
Ward, Laurence |
People |
Michael Fulp |