1、Printed in U.S.A. Copyright Gypsum Association 2000. All rights reserved.GYPSUM ASSOCIATION810 FIRST STREET NE, #510 WASHINGTON, DC 20002REPAIR OF GYPSUM BOARDJOINT RIDGING(GA-221-2000)Joint ridging, also called beading, is auniform, fine line deformation occurring atgypsum board joints. It is usual
2、ly caused bycompression of the edges or ends of the finishedand decorated gypsum board resulting from theedges or ends being forced together fromexposure to alternating periods of high and lowtemperature and humidity extremes due tothermal or hygrometric expansion.In order to permit the gypsum board
3、 systemto stabilize, it is recommended that repairs notbegin until the affected building has gonethrough at least one complete heating/coolingcycle. Repairs should only be undertaken in awarm, dry environment.Lightly sand the ridge down taking care notto damage the embedded joint reinforcing tape.Ty
4、pical Joint Before RidgingTypical Joint After RidgingTypical Ridging at Taper-to-Butt JointFill the surface over the joint with topping orall purpose compound, feathering as wide asnecessary to create an essentially flat surface.Allow compound to dry for at least 24 hoursbefore proceeding. After the
5、 compound is dry, itmay be lightly sanded to feather the edges andremove any remaining trowel marks. Examinethe sanded joint to determine whether or not theridge has been eliminated. If the examinationindicates that the ridge has not been adequatelyconcealed, additional feathering coats of jointcomp
6、ound may be required. Allow each coat ofjoint compound to dry at least 24 hours beforesanding.The repaired joint should be painted with acoat of drywall primer and allowed to drythoroughly prior to the application of finaldecoration.Typical Ridge From Misaligned FramingMEMBER COMPANY LIST2001AMERICA
7、N GYPSUMBPB AMERICA, INCCONTINENTAL GYPSUM COMPANYG-P GYPSUM CORPORATIONJAMES HARDIE GYPSUMLAFARGE GYPSUMNATIONAL GYPSUM COMPANYPABCO GYPSUMA Division of Pacific Coast Building Products, Inc.TEMPLE-INLAND FOREST PRODUCTS CORPORATIONUNITED STATES GYPSUM COMPANYWESTROC INC.GYPSUM ASSOCIATION810 First Street NE, #510Washington, DC 20002202-289-5440Fax: 202-289-3707www.gypsum.org
