Boiler Room / Basement

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
Rule Type: 
Board Approval: 

Boiler room renovation only.

Prince George's County: 

Permit required.

City of Greenbelt: 

Permit required.