Frequently asked questions - lead drywall
Q: My walls will be 8 or 10 feet high, why is the lead only up to 7 feet?
A: Federal regulations require the lead shielding to go to a minimum of 7 feet because very few people are taller than 7 feet. Radiation is linear so it can not go up over a wall and then come back down, it continues to travel in a straight line. However, if there is occupancy above the imaging room (more rooms on an upper level), then lead shielding will be required to the full wall height AND on the ceiling.
Q: When is lead shielding required on the ceiling or floor?
A: Ceiling and floor lead is typically only required if there is occupancy above of below the imaging room. If the imaging room has rooms below it, floor lead will be required, if there are rooms above it, ceiling lead is required. Anytime a shielding report states that ceiling or floor lead is required, it must be followed, even if there is no occupancy above or below.
Q: Do I need to cover the screwheads with lead discs and batten strips at every joint?
A: We provide 50 lead discs and one batten strips per sheet, while others charge extra for these products. The discs are not always required, but a batten strip is always required at every joint. Per NRCP report 147: "For typical shielding applications, a lead sheet is glued to a sheet of gypsum wallboard and installed lead inward with nails or screws on wooden or metal studs. X-ray images of wall segments show that insertion of the nails or screws does not result in significant radiation leaks. In fact, the steel nails or screws generally attenuate radiation equally, or more effectively, than the lead displaced by the nails. Therefore, steel nails or screws used to secure lead barriers need not be covered with lead discs or supplementary lead. However, where the edges of two lead sheets meet, the continuity of shielding shall be ensured at the joints"
Q: Is there a standard lead thickness for x-ray rooms?
A: There isn't a standard lead thickness required for radiation imaging rooms. Each room has many factors that contribute to the lead shielding requirements. Some of these factors are: the energy level of the machine (how much radiation it produces and which direction it is pointed), work load (how often the machine is used), the existing construction of the room (drywall and stud walls require more shielding than concrete walls), surrounding rooms (walls shared with a children's care unit will require much more shielding than walls shared with a storage closet), and other variables are taken into consideration when a physicist is calculating the lead shielding requirement. See next question for more info.
Q: What is a shielding report? How do I find out the lead equivalency required?
A: A radiation shielding report is a document written by a radiation physicist. It describes the lead thickness or lead equivalency required on each wall of your imaging room. Federal law stipulates that every facility must have a shielding evaluation done for every imaging room. They are also required if something changes in the room, like replacement of an imaging machine. In some areas, this can be handled by your county health department. Sometimes, the company you bought the x-ray machine from can acquire one for you. Due to a perceived conflict of interest, we cannot be involved in the shielding report acquisition. But if you have a shielding report and don't know how to decipher it, you can email it to us with your quote request and will we quote the proper products.