SHOWER BACKER BOARD FREQUENTLY ASKED QUESTIONS

GOBOARD® BACKER BOARD QUESTIONS

WHAT IS GOBOARD®?

GoBoard® is an ultra-lightweight yet durable, waterproof alternative to cement and other heavy tile backer boards and is manufactured by Johns Manville, a Berkshire Hathaway company.

WHY DO I HAVE TO USE TILE BACKER BOARD?

Tile backer boards provide a stable surface upon which to bond tile. GoBoard® offers the advantages of being ultra-lightweight, easy to cut, handle and install. And, best of all, it has waterproofing already built-in.

WHAT GOBOARD® SIZES ARE AVAILABLE?

GoBoard® is available in 2 kits:
- 6 Sheets 3' x 5' x 1/2" Shower Wall Board with 2 lb. of screws, & 4 tubes of ShowerSeal® Polyurethane sealant (covers 90 square feet total) View ▸
- 8 Sheets 3' x 5' x 1/2" Shower Wall Board with 2 lb. of screws, & 6 tubes of ShowerSeal® Polyurethane sealant (covers 120 square feet total) View ▸

HOW MUCH DOES GOBOARD® WEIGH?

Our 1/2" GoBoard® weighs 7.5 pounds, up to 80% lighter than cement and other heavy boards.

WHAT MATERIALS ARE USED TO MANUFACTURE GOBOARD®? HOW CAN IT BE LIGHTWEIGHT AND STRONG AT THE SAME TIME?

GoBoard® exterior faces are comprised of proprietary coated fiber glass mats that provide excellent bonding and stiffness. The core is made from high density polyisocyanurate (“polyiso”) closed-cell foam, providing strength, durability and waterproofness. Polyiso is a frequently used building material for insulation, roofing and other applications.

WILL GOBOARD® BREAK BECAUSE IT IS SO LIGHT? IS IT STRONG ENOUGH FOR MY TILE INSTALLATION?

GoBoard® high density polyiso core leads to product compressive strengths of >250 psi (4"), >200 psi (2"), and >200 psi (s"), resulting in Robinson Floor Test (ASTM C627) ratings of Light Commercial for both the 4" and 2" sizes.

GOBOARD® IS "WATERPROOF" AND OTHER TILE BACKER BOARDS ARE "WATER RESISTANT" - WHAT IS THE DIFFERENCE?

GoBoard® core is waterproof, passing ASTM D4068 testing. Water will not pass through the board like it will with cement boards, which require separate waterproofing over the entire board. Seal only the board joints and fastener locations for a waterproof tile assembly (board joints and fastener locations require a waterproof sealant per GoBoard® installation instructions).

GOBOARD® IS MORE EXPENSIVE. WHY SHOULD I USE IT?

Despite having a higher purchase price than other heavy tile backer boards, GoBoard® has a lower installed material cost because the installer avoids much of the expense of waterproofing the entire board. GoBoard® saves time due to it being easy to transport, carry and maneuver into fastening position. It can be cut right where it’s installed with a basic utility knife without crumbling or disintegrating. This also helps the installer avoid the mess of cutting cement and other heavy boards.

CAN GOBOARD® BE USED IN WET AREAS?

Yes! Because it is waterproof, GoBoard® is an excellent tile backer board for wet areas.

CAN GOBOARD® BE INSTALLED OVER CONCRETE FLOORS?

Yes, the concrete floor must be clean and fully cured, and surface imperfections must be pre-filled with mortar prior to GoBoard® installation. Laminate GoBoard® to a concrete floor by fully embedding it in mortar.

HOW DO YOU CUT GOBOARD®?

For linear cuts, lightly score GoBoard® on one side with a basic utility knife, then quickly snap to desired size. For radius and interior cuts (pipe, sink, drain cutouts, etc.), cut through GoBoard® with a utility knife and then pop the cut-out piece out with your fist, hammer, etc.

DOES GOBOARD® HAVE A TOP OR BOTTOM?

Because the core is waterproof, either side can be installed face up. However, we have provided marks every 8" on the printed side to serve as a guide to help with fastening.

HOW IS GOBOARD® FASTENED?

Use GoBoard® Fasteners (14" long), backer board screws (14" long), galvanized roofing nails (1 1/2" long) or 16 gage galvanized staples (1" x 1") to fasten GoBoard®. For walls and ceilings, fasten GoBoard® to the studs with GoBoard® Fasteners flush to the surface of the board at a maximum spacing of 8" and within 1" of the perimeter edges. For wood floors and countertops, first laminate GoBoard® with mortar to subfloor or countertop plywood base, fasten GoBoard® with GoBoard® Fasteners flush to the surface of the board at a maximum spacing of 8" and within 1" of the perimeter edges (fastening is not required for concrete floors), and then embed fiber glass mesh tape in mortar at the joints.

HOW IS GOBOARD® BONDED TO FLOORS?

Use a dry set mortar compliant with ANSI A118.1 standard or Polymer modified thin-set mortar compliant with ANSI A118.4 standard. (Bonding is required for both concrete and wood floors).

HOW DO I SEAL TO ENSURE A WATERPROOF INSTALLATION?

GoBoard® itself is waterproof. To ensure a waterproof tile assembly, all fastener locations and joints (between boards, at corners and for other changes of plane) must be sealed completely with GoBoard® Sealant or a waterproof sealant (see www.jm.com/goboard for approved alternative sealants). To ensure good mortar adherence and a durable installation, use a polyurethane (not silicone) caulk. For faster and easier sealing of wall joints, liberally apply a continuous bead of sealant (caulk) to the board edge, gently butt boards together squeezing the caulk out leaving a 8" gap, finally spreading the excess caulk across the joint with a putty knife at least 1" on either side of the joint to form a waterproof seal. Alternatively (and for floors and countertops), leave a 8" gap between boards, fill all joint gaps with mortar, place 2" fiber glass mesh tape on the joints and embed with mortar (ensuring tape is fully covered), then seal all joints and fastener locations with two coats of liquid waterproofing membrane.

WHY DO I HAVE TO SEAL THE SEAMS AND FASTENER LOCATIONS? HOW MUCH SEALANT SHOULD I USE?

When GoBoard® is penetrated with fasteners, channels are created through which water can pass. Similarly, the joints between boards and all changes of plane also serve as channels. For walls, use a liberal amount of caulk between each board so that the excess squeezes out. Spread the excess caulk with a putty knife at least 1" on either side of the joint to form a waterproof seal. Alternatively (and for floors and countertops), fill the joints with mortar, embed fiber glass mesh tape and then seal the joints and fastener locations with two coats of liquid waterproofing membrane making sure to extend the liquid proofing membrane at least 1" beyond mortar.

IS GOBOARD® HAZARDOUS?

GoBoard® is non-hazardous. We recommend wearing gloves, safety glasses, long sleeve shirts and pants and following good safety practices when installing GoBoard®. Temporary mechanical abrasion (itching) of skin, eyes and respiratory tract may occur upon exposure to fibers or dust during handling. GoBoard® contains no cement.

IS GOBOARD® FLAMMABLE? DOES IT HAVE A FIRE RATING?

GoBoard® passes ASTM E-84 testing per IBC requirements. If a 1-hour fire rating is required, GoBoard® should be installed over materials that provide this rating.

IS A VAPOR MEMBRANE REQUIRED FOR WET AREA WALL APPLICATIONS?

GoBoard® does not require a vapor barrier for wall applications unless required by local building codes or when installed in steam shower applications.

K-BOARD BACKER BOARD QUESTIONS

WHAT IS K-BOARD?

The K-Board, or KBRS Backer Board is a lightweight, waterproof and vapor-retardant backer board that consists of a extruded polystyrene rigid foam core. The rigid foam is reinforced with glass fiber mesh (with alkali-resistant finish) on both sides and coated with a polymer-modified cement.

WHY DO I HAVE TO USE TILE BACKER BOARD?

Using KBRS Backer Board to build walls over stud framing in wet areas is an efficient alternative to using gypsum board. While cement backer boards are moisture-resistant, they are not waterproof. Thus, additional measures must be taken to protect wall cavities from water and vapor penetration.

WHAT K-BOARD SIZES ARE AVAILABLE?

K-Board is available in 2 kits:
- 6 Sheets 3' x 5' x 1/2" Shower Wall Board with 200 Washers, 200 Screws, & 4 tubes of ShowerSeal® Polyurethane sealant (covers 90 square feet total) View ▸
- 8 Sheets 3' x 5' x 1/2" Shower Wall Board with 200 Washers, 200 Screws, & 6 tubes of ShowerSeal® Polyurethane sealant (covers 120 square feet total) View ▸

HOW DO I INSTALL KBRS BACKER BOARD (K-BOARD)?

XPS Foam Backer Board can be installed over wood and metal studded walls horizontally or vertically by using the Galvanized Screws & Washers. All vertical joints must be supported by suitable, load-bearing framing.

Maximum spacing of studs is 16 inches on center.

STEP 1:
Place screws & washers 12 inches apart vertically and 16 inches apart horizontally. It is best when applying the screws to create a slight depression in the board to reduce any buildup at the screw. Vertical seams must be staggered.

STEP 2:
Seam Waterproofing

Method 1 (KBRS ShowerSeal® Polyurethane Sealant)
Cover all seams and screw/washer dents with polyurethane adhesive. Flatten the excess adhesive with a spackle knife. Make sure all seams are fully covered for a watertight seal.

Method 2 (Seam Tape)
Cover all seams and screw/washer dents with thin-set and seam tape. Make sure all seams and screws/washers are fully covered with a minimum 2 inch overlap (approximately a 4.5” patch to cover washers). Use a grout float to remove any excess thin-set and air pockets.

GENERAL QUESTIONS

WHAT IS THE KBRS RETURN POLICY?

Standard or stock items may be returned within 30 days of purchase if purchased directly from KBRS, Inc - by internet, phone or fax. Standard or stock item(s) may be returned for credit or refund of the purchase price paid, less a 15% restocking fee. Custom product(s) or special orders are NOT eligible for return, credit or refund at any time; unless the product is received defective or the return is a direct result of a KBRS, Inc. error. To return an item you must first contact us via phone (866) 912-3211, or email returns@kbrsinc.com to obtain an RMA number. Item(s) must be returned in original packaging and return shipping must be paid by you, it is strongly recommended you insure your return package as KBRS will not be able to refund an item that arrives damaged and is not in re-stockable condition.
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DOES KBRS PROVIDE RETURN SHIPPING LABELS

Currently we do not provide shipping labels to have our products returned to us. Customers are required to return their products with the shipper of their choice. It is also recommended you insure your returned items, to protect form damages that may occur from shipping. KBRS will not be able to offer refunds on products that are returned damaged. All returns must be sent back to the warehouse in re-stockable conditions.

IF ALL MY PACKAGES DO NOT ARRIVE WHAT SHOULD I DO?

Since all of your products are packaged separately, it is common for items to get separated in the shipping process. Usually the missing product will arrive the next business day. If the product does not arrive by the end of the next business day, please contact us for a complete resolution.