Commercial Contractors Serving the Mid-Atlantic Region

Projects & Photos

The Smithsonian National Museum of African American History and Culture is a place where all Americans can learn about the richness and diversity of the African American Experience. During Construction of this museum, water began leaking through the foundation walls and floor. SGS stopped these leaks by means of urethane injection, drilling and installing injection ports around cracks in the walls and floor showing evidence of protruding water. SGS then injected urethane gel into the concrete, stopping all leaks to date. SGS drilled and installed injection ports around various cracks in the walls and floors that showed evidence of protruding water. SGS then injected urethane gel grout into the concrete and stopped all leaks to date.

Urethane Injection

Smithsonian National Museum of African American History
 and Culture
 1400 Constitution Ave., NW Washington DC


This job needed service from SGS to increase the strength of the 1st floor support columns in this high rise building. After metal jackets were installed around the 87 concrete columns, SGS pumped non-shrink, high strength grout between the columns and jackets in order to increase each column’s overall strength.

Jacket Grouting

Hoffman Town Center - Structural Group
 2034 Eisenhower Avenue, Alexandria, VA


SGS was proud to partner up with Manhattan Construction to perform this historic façade restoration and waterproofing of the Ryan and Mulledy Hall buildings at Georgetown University. This challenging project included a full tuckpoint of all existing masonry, stone repair, exterior and interior waterproofing, new masonry construction, structural repairs, and full exterior cleaning.

Full Façade Restoration and Waterproofing

Manhatten Construction tuckpointing and waterproofing
 Georgetown University
 Washington D.C.


Formerly the Lorton Prison, this historic structure has been restored to art galleries and studios and also hosts live performances. Due to the fact that the underground utility tunnels were aging and contaminated with asbestos, SGS filled all underground utility tunnels to the ceiling with approximately 2,500 cubic yards of grout.

Asbestos Abatement, Void Filling, Tunnel Grouting

Lorton Workhouse Arts Center - HITT Contracting
 9520 Workhouse Road Lorton, VA


SGS mobilized to complete multiple repair and new construction scope items in order to help our client complete this challenging, fast-paced project.

Tasks on this project included installing new concrete, concrete repair, steel column base grouting, slab jacking, storm water tank remediation, water filter installation, and concrete slab overlayment.

Concrete, Slabjacking, Grouting

Barry Farms Recreation Center / Whiting-Turner Contracting
 1230 Sumner Road SE
 Washington D.C.


SGS replaced an old waterproofing system with a new waterproofing membrane and drain tile. SGS removed the old membrane, cleaned and prepared the wall, and placed new sheet membrane. SGS also installed drain board prior to backfilling to existing grade

Exterior Waterproofing Membrane with Drain Tile

Patuxent Wildlife Research Center - U.S. Geological Survey
 1200 Beech Forest Rd Laurel, MD


Sculptor Alexander Calder created “Gwenfritz,” a 35 ton sculpture reaching skyward with its jagged angles and rich matte paint. It was relocated to its original location in 2014 with a reflection pool built around the perimeter. SGS installed a waterproofing membrane to keep the reflection pool from leaking. In order to do this, SGS constructed a decorative vinyl chip flooring system with moisture mitigation.

Waterproofing Membrane

Smithsonian Calder Relocation Project - Grunley Construction
 Company, Inc.
 14th Street and Constitution Ave, NW, Washington, DC


With water leaking through the cracks in the ceiling of this parking garage, SGS sealed 81 linear feet of cracks in the ceiling. Our team drilled holes on both sides of the cracked concrete, installing injection ports and pumping urethane waterproofing gel grout into each of the ports.

Urethane Injection

Petworth Safeway – Duball, LLC.
 3830 Georgia Avenue,
 NW Washington, DC


The corrugated metal storm water management pipes had rusted through the bottom and sides of the pipes causing erosion and washout underneath the headwall. SGS placed and filled grout bags under the headwall to fill the 3 foot voids and stabilize the soil beneath. Additionally, our crew filled the voids behind the wall and in between the grout bags for maximum stabilization.

Storm Water Infrastructure Erosion Repair with Grout Bags

Storm Drain Outfall Restoration Strohecker
 Brockbridge Rd., Laurel, MD


SGS placed and filled grout bags to promote the stabilization of the soil while also preventing erosion under the bridge.

Soil Stabilization of Stream Bed Under Bridge

Grout Bags Strohecker
 Harwood Road Bridge
 Annapolis MD


SGS stabilized a storm water management pipe that had completely fractured in half. Our team stabilized the pipe and the surrounding eroded areas with grout bags as well as filling the voids behind the bags with grout.

Storm Water Infrastructure Erosion Repair with Grout Bags

Culvert Restoration Project -
 Strohecker
 528 Saltworks Ct. Annapolis, MD


The concrete slab supporting the trash compactors had sunk about 4 inches because of voids below the surface. SGS raised the concrete slab to its original height so that it would lie flush with the adjacent concrete slab and retaining wall. Our crew pumped grout into various holes, filling the underground voids and raising the concrete slab to its original elevation.

Slab Jacking

Cordoza High School - GCS Inc. 1200 Clifton Street NW Washington, DC


SGS grouted the soil behind the gabion walls around the entire perimeter of the storm water management ponds to prevent water leakage. SGS drove 140 2” caissons around the perimeter of the two storm water management ponds. Our team then pumped grout in each caisson to fill the voids and create a solid foundation in which a new sidewalk was to be installed. Additionally, this process sealed the leaks in the ponds.

Soil Grouting

National Memorial Park -
 Total Development Solutions
 7482 Lee Highway, Falls Church, VA


The Pepco conduits that pass through the switchgear were leaking. SGS sealed the conduits to keep the water out. Our team placed the injection and vent tubes into the leaking conduits and sealed them with a cement cap. We then injected waterproofing gel grout into the tubing to create a slug inside the conduit. Once the conduits were filled, the tubes were cut and sealed with hydraulic cement.

Acrylamide Grouting, Conduit Sealing

UMUC Academic Center at Largo - PEPCO
 1616 McCormick Drive Largo, MD


The Woodrow Wilson Memorial Bridge spans the Potomac River between Alexandria, VA. and Oxon Hill, MD. SGS was originally hired by Potomac Crossing Consultants in 2004 during the replacement project. Once on site, several other companies hired SGS for the project in the ensuing years. Initially, SGS completed epoxy injections into cracks in the precast structures being manufactured on site using man lifts and barges. Later in the project, SGS injected voids around the anchor heads of the post-tension cables. Finally, SGS designed a camera and remote packer system to seal the leaking joints in the post-tension conduits that were placed in the foundation below the water table.

Epoxy Injection
 and Waterproofing

The Woodrow Wilson Memorial Bridge


The historic restoration and renovation of St. Elizabeths Hospital called for the masonry chases to be filled with low strength grout in order to stabilize the façade for repairs. Our team pumped approximately 300 cubic yards of grout into the voids strengthening the building’s structure.

Void Grouting in Masonry

St. Elizabeths Hospital
 1100 Alabama Ave SE
  Washington DC