top of page


High Density Mortar and Grout 

NSS never uses any lead in our high density, heavyweight concrete shielding products. Our products are all completely non-toxic and environmentally safe.

NSS high density (heavyweight) Grout (ShieldGROUT®) is designed as a complement to the NSS High Density ShieldBLOCK® pre-fabricated modular radiation shielding units. Specially formulated to match the required density of the ShieldBLOCK®, ShieldGROUT® is used to fill in areas, as needed, to achieve a homogenous shielding barrier.


ShieldGROUT® workability can be adjusted for use as a mortar for structures consisting of solid ShieldBLOCK® rectangular units or for use as grout for filling the cells for 2-core ShieldBLOCK® installation projects.


ShieldGROUT® is also commonly used in leveling and tie-back layers when laying interlocking ShieldBLOCK® units.

ShieldGROUT® can also be used as an individual shielding material when space is limited for or other shielding applications such as Linac Vaults.

ShieldBLOCK® pre-fabricated modular radiation shielding units offer factory controlled quality and the ability to be installed virtually anywhere at any time.  ShieldBLOCK® pre-engineered kits come complete with everything you need, to shield your linear accelerator vault or treatment room, including installation. 


NSS will custom formulate the most affordable solution for you using our wide selection of minerals. ShieldGROUT® high-density (heavyweight) mortar and grout is an equivalent density complement to ShieldBLOCK® systems.

NSS high density (heavyweight) ShieldBLOCK® and ShieldGROUT® are commonly used for linear accelerator vault upgrades or additions where a higher energy machine is replacing an older unit or where a new machine in being installed in an unshielded or under-shielded room. Depending on the situation, we manufacture and carry a space-saving block type and density for any circumstance.

Chevron-type high density (heavyweight) ShieldBLOCK® interlock with each other on all four sides, preventing radiation from streaming through. They are popular for their ease of installation and for the fact that they are assets which may be depreciated, moved, and reused if necessary.

Solid rectangular high density (heavyweight) ShieldBLOCK® and equivalent density ShieldBLOCK® can be installed by local masons using standard masonry techniques.


2-core high density (heavyweight)  CMU ShieldBLOCK® provide structural value in construction when used with sufficient rebar and equivalent density ShieldGROUT® to fill the cores. They provide the same structural benefits as poured or pumped high density concrete for supporting loads and resisting forces.

NSS High Density (Heavyweight) ShieldBLOCK® are Available in Various Profiles and Sizes

Interlocking, chevron-type high density (heavyweight) Blocks

  • 4" x 6" x 17"

  • 6" x 6" x 12"

Solid, rectangular high density (heavyweight) blocks with equivalent density ShieldGROUT™ as needed

  • 4" x 4" x 16"

  • 4" x 8" x 16"

2-Core high density (heavyweight) CMUs with equivalent density ShieldGROUT®  for filling the cores

  • 6" x 4" x 16"

Each of these profiles are stocked in both 250 pcf (4.01 g/cc) and 300 pcf (4.81 g/cc) densities.


Compared to a conventional concrete treatment room, the increased density can eliminate up to half your shielding thickness and save valuable space.


You benefit from this recovered floor space with increased treatment areas and/or decreased overall footprint (and associated costs) of the treatment room, excavation, foundations, finishes, etc.

bottom of page