Lead Lined Plywood: MarShield™ Building Products

Purpose: MarShield’s plywood is laminated with sheet lead that is designed to cover necessary surfaces or walls in a room requiring radiation shielding. It is affixed to surfaces or walls ensuring a continuous layer of sheet lead, under the plywood, to a specified height. It is used in new construction or shielding upgrade/renovations for P.E.T and other types of diagnostic imaging rooms and to fill the void between lead-lined drywall and interlocking lead bricks

Product Details: MarShield starts with a piece of sheet lead meeting or exceeding Federal Specifications QQ-L-201F, Grade C, ASTM B-749-03 Standard Specification for lead and lead alloy strip, sheet, and plate products. The lead sheet is 99.9% Pure or better of un-pierced virgin lead, free of dross, oxide inclusions, scale, laminations, blisters and cracks and is factory laminated to plywood panels. The Plywood is available in 5/8” to 3/4” in thickness with a lead thickness of 1/16” no less to 1/2" maximum thickness. The Fire-Retardant Plywood conforms to AWPA C27 type A. – Sanded and good one side.

Lead laminated to plywood is applied in 48” widths on equal plywood widths up to 96” lengths. 2” wide batten strips can be supplied to cover all joints where applicable. Lead lined plywood is typically recommended for heavier lead shielding requirements, usually when the lead shielding exceeds 1/8” thick.  Lead lined plywood at these thicknesses becomes very heavy to handle in full sheet form (4’ x 8’).  We recommend having us cut the lead lined plywood into widths that equal your on-center stud dimensions (e.g. 12” or 16”).  This will make the lead lined plywood much more manageable for the installer.

Example:

1 sheet of 3/4 ” x 4’ x 8’ plywood with 1/4 ” lead lining to 7’ weighs approx 505 lbs.
1 sheet of 3/4 ” x 16” x 8’ plywood with 1/4 ” lead lining to 7’ weighs approx 168 lbs

Smaller panels will require more batten strips but the ease of handling these lighter panels will be offset in the extra cost and labor during the installation process. Similar to leaded drywall, the installer will need to take into account the loss of shielding in all penetrations, seams and cut outs in the leaded plywood. Shielding will need to be added to all receptacle switches, fasteners penetrations and seams created when applying the leaded plywood. In the majority of installation jobs the leaded plywood panels can be mounted directly to the metal studs with standard drywall screws. Leaded plywood panels may be used in the ceiling but may required addition support of fasteners to hold the panels to the ceiling.

Installation: It is important to ensure the installation is done in accordance to local state or provincial standards and code regulations as outlined for each municipality. All panels will be affixed to heavy gauge metal studs sufficient to support the leaded plywood. Screw or fasten lead-lined panels 8 inches on center at panel edges and 12 inches on center to intermediate framing members.   Erect all panels in a vertical position where possible or horizontally where required by local codes.

Sample Leaded Plywood Weights

Plywood 5/8” thick with 1/16” thick lead    =        5.703  pounds per square foot

Plywood 5/8” thick with 1/8” thick lead      =        9.453  pounds per square foot

Plywood 5/8” thick with 3/16” thick lead    =        13.203 pounds per square foot

Plywood 5/8” thick with 1/4” thick lead      =        16.953 pounds per square foot

Plywood 5/8” thick with 1/2” thick lead      =        31.953 pounds per square foot

Plywood 3/4” thick with 1/4” thick lead      =        505 pounds per square foot


If you have a recent project that incorporated our products, we’d like to see it. Please send us photos and descriptions showing our products; your work could be featured as a case study on our website or in our newsletter. Send any materials to sales@marsmetal.com

DIAGNOSTIC RADIATION SHIELDING CONSIDERATIONS


All Lead Radiation Shielding requirements should be calculated and determined by a certified professional radiation health physicist based on the following information.

ENERGY: The end user must determine the output of the X-Ray machine. (KvP). Usually, the higher the output of the machine, the higher the lead shielding requirement.

EXPOSURE:   The end-user must determine the exposure per hour, day, week and year and the maximum patient exposure accumulated and projected from radiation exposure, as radiation is cumulative and unnecessary extra exposure can cause biological damage on the cellular level. Each state or province has its own maximum permissible exposure level in addition to natural radiation exposure an average person is exposed to through environmental factors like ultra violet solar, radon gas and atmospheric radiation. Ensure you check with local governing health and safety laws and codes for current compliance requirements.

ORIENTATION/DIRECTION: All wall sections shall be calculated by your physicists in relation to the direction of the primary beam target. (Direction where it is aimed) and scatter or secondary radiation of the x-ray machine, as well as the floor or wall.

DISTANCE: Radiation dissipates as the distance increases; usually the closer a partition is to the radiation / x-ray source, the higher the lead shielding needed.