Interior Finishing of Underground Areas
Article Type:
GHI Homes Category:
Updated:
Thursday, January 26, 2006
Summary & Standards
last revised Jan 27, 2006
| Underground Finishing | Summary below provided for general information purposes; current GHI rules supercede any abbreviated guidelines | |
| GHI | rules | §X.B.7 |
| permit request | type I, II | |
| neighbor consent | not required | |
| Board approval | boiler room renovation only | |
| Prince George's Cty City of Greenbelt |
permit | required direct egress to exterior is required |
Interior finishing of underground areas (boiler rooms, townhouse basements, masonry basements) requires careful consideration of construction details, to avoid future problems with water infiltration, fungal growth, and indoor air quality. This plan relies upon an interior perimeter drain and sump pump to eliminate infiltrating groundwater by drawing the level down to the perimeter drain, and minimizing moisture migration through living space walls by waterproofing from the exterior. The following details are required based upon use of the area:
| Boiler room living space | Townhouse, masonry basement | ||
|---|---|---|---|
| detail | above grade | below grade | below grade |
| 6 mil polyethylene vapor barrier lapped 6" min at all seams and onto vertical walls, leakproof basement access door | required | required | |
| perimeter drain at the designated elevation, forming a complete circuit inside the exterior walls, draining into a sump pit; sump pump expels water to exterior | required just below the vapor barrier | required just below the bottom of the floor support structure | required below level of basement slab |
| venting for area below living space | per code if crawl space, powered ventilation if storage | ||
| waterproof exterior walls | required down to elevation of perimeter drain | required down to elevation of perimeter drain | |
