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FREQUENTLY ASKED QUESTIONS ON wedi BUILDING PANELS & wedi FUNDO SHOWER SYSTEMS



What is the wedi building panel?

What is it made of?

Who produces it?

Why is the wedi Building Panel waterproof as opposed to “water resistant” backerboards?

What sizes are available?

How much do the wedi building panels weigh?

Does the wedi building panel have an R-Value?

Does the wedi building panel have a fire rating?

Does the wedi Building Panel have sound deadening qualities?

Can it be used on floors?

On the floor should I leave room for expansion joints between wedi Building Panels?

Should I stagger my joints?

Can the wedi Building Panel be installed on walls?

Can I install the wedi Building Panel directly to the studs?

Can I install the wedi Building Panel over green board/drywall?

Can I use the wedi Building Panel in an exterior application?

How is the wedi Building Panel cut?

Do the seams in an installation have to be taped?

Is the wedi Building Panel strong enough for my ceramic tile installation?

In wet areas does one have to use the wedi Waterproof Sealing Tape or wedi Joint Sealant?

How is the joint tape applied?

The wedi Building Panel can be dented when pressure is applied, will this cause problems after ceramic tile is adhered over these dents?

Is the wedi Building Panel's foam toxic?

The wedi Building Panel is more expensive than the other tile backerboards. Why should I use this product?

What is the wedi Fundo Shower Pan?

Which wedi Fundo Shower Pan sizes are available?

Can I cut the wedi Fundo Shower Pan to size?

Can I extend the wedi Fundo Shower Pans?

Do local building codes allow the wedi Fundo Shower Pan system to be used instead of a conventional shower pan liner and mortar bed construction?

How much time does it take to install the wedi Fundo Shower Pan?

Why is a wedi Fundo Shower Pan installation less expensive than traditional shower pan liner-mortar bed construction?

Which ceramic tile sizes can be used with the wedi Fundo Shower Pan?

Why is the wedi Fundo Shower Pan so much safer than a conventional concrete shower pan?

Can I use the wedi Fundo Shower Pan with any other ceramic tile backerboard other than the Wedi building panel?

How do I instruct the plumber to setup the drain system before installing the wedi Fundo Shower Pan and pressure fit drain assembly?

What is the height of the wedi Fundo Shower Pan?


FAQ


What is the wedi building panel?

The wedi Building Panel is a waterproof tile underlayment for walls and floors, manufactured by wedi GmbH in Emsdetten, Germany. It consists of an extruded, polystyrene core and is covered in a fiberglass mesh and polymermodified cement coating.
The blue foam core is closed cell, extruded polystyrene that does not allow the transfer of water and retards water vapor transmission.
The glass mesh adds strength and rigidity to the building panels. The cement coating allows for adhesion as a bonding surface. The board is engineered to be used in interior applications for the installation of ceramic tile on walls, floors and countertops.
The wedi Building Panel is available in 2'x 4 ', 3'x 5' and 2'x 8' sheets in various thicknesses 1/8", 1/4", 1/2", 5/8", 1", 1 1/2" and 2".


What is it made of?

The wedi Building Panel is made up of three components: foam, mesh, and mortar. The blue foam is extruded polystyrene (Styrofoam). It is inherently waterproof as it provides a closed cell matrix.
This is due to the process under which the foam is created. The foam is extruded under enormous pressure, creating a dense mass of tiny, closed cells so tightly packed together that water cannot penetrate the insulation, nor can the insulating air escape from the cells.
The single foam cells share the surrounding cell foam walls with the neighbor cells so that no room is left open in between the single cells in the matrix. The foam is then covered with a glass mesh to add strength and rigidity, which in turn is coated with a polymer-modified cement coating.




Who produces it?

It is manufactured in Emsdetten, Germany by wedi GmbH, which has been producing the Building Panels since 1982. Why is the wedi Building Panel waterproof as opposed to "water resistant" backerboards?
The wedi Building Panel is 100% waterproof because of the material it is made of. The extruded polystyrene core is different than more common compressed expanded Styrofoam. For example, the foam used to make a standard white coffee cup is highly compressed expanded Styrofoam. Little balls of foam are compressed tightly together to hinder the passage of liquid through the independent pieces of foam. However, compressed foam will allow for liquid to move around the units of which it is made. This is why a liquid stain can often be found beneath a Styrofoam cup sitting on a cold granite countertop after it has allowed vapor transfer created by hot coffee or tea.
The foam that wedi Building Panels consist of is extruded foam; this means that the foam is created through a process of infusing a styrene resin with a blowing agent. This results in a foam matrix that is honeycomb in nature. It is a single piece of foam with air pockets within. The extrusion process creates foam that is closed cell; it is lacks voids through which water can migrate.




Why is the wedi Building Panel waterproof as opposed to “water resistant” backerboards?

The wedi Building Panel is 100% waterproof because of the material it is made of For example, the foam used to make a standard white coffee cup is highly compressed expanded Styrofoam However, compressed foam will allow for liquid to move around the units of which it is made. The foam that wedi Building Panels consist of is extruded foam; this means that the foam is created through a process of infusing a styrene resin with a blowing agent. It is a single piece of foam with air pockets within.
The extruded polystyrene core is different than more common compressed expanded Styrofoam Little balls of foam are compressed tightly together to hinder the passage of liquid through the independent pieces of foam This is why a liquid stain can often be found beneath a Styrofoam cup sitting on a cold granite countertop after it has allowed vapor transfer created by hot coffee or tea. This results in a foam matrix that is honeycomb in nature. The extrusion process creates foam that is closed cell; it is lacks voids through which water can migrate.



What sizes are available?

The wedi Building Panel is available in 2'x 4', 3'x 5'and 2'x 8' sheets in various thicknesses 1/8", 1/4", 1/2", 5/8", 1", 1 1/2" and 2".



How much do the wedi building panels weigh?

The wedi Building Panels vary in weight depending upon the thickness of the board. In the 3 x 5 ft. size 1/4" is 8.07 lb, 1/2" is 8.67 lb, 5/8" is 8.97 lb and the 1" is 11.4 lb.




Does the wedi building panel have an R-Value?

Yes. The R-value varies depending upon building panel thickness at a rate of 4.3 per one (1) inch.




Does the wedi building panel have a fire rating?

The wedi Building Panel will not provide a thermal barrier. It will not add anything to a fire, as the cells of the foam will collapse due to extreme temperatures above 175°F. Where a one-hour firewall is required, the wedi building panel should be applied over a surface that can provide such a rating.




Does the wedi Building Panel have sound deadening qualities?

The wedi Building Panel is not engineered to be used as a sound deadening underlayment.



Can it be used on floors?

The wedi Building Panel functions as an excellent substrate for most flooring applications. Wedi Building Panel has been rated for heavy-duty commercial use by the Tile Council of North America (TCNA) using the industry standard known as the Robinson Floor Test.
It can be applied over a wooden or concrete subfloor. When applied over plywood, the recommended joist spacing is 16" on center, 5/8" or greater plywood with no deflection in the subfloor greater than L/360 as outlined by the TCNA, following local building codes or the IRC. If applied over a cement subfloor the slab should be fully cured and free of debris. The board will function as a crack bridging membrane because cracks in the cement subfloor will not transfer through the foam as easily as through other inelastic tile backerboards.




On the floor should I leave room for expansion joints between wedi Building Panels?

No, the wedi Building Panel is inert and will not shrink or expand over time. All wedi Building Panels should be butted together. An expansion joint around the perimeter of the floor should beconsidered, leaving a gap of 1/8" to the surrounding walls to better resist structural movement.




Should I stagger my joints?

Yes, the wedi Building Panels should be staggered to minimize the length of breaks in the substrate.



Can the wedi Building Panel be installed on walls?

The wedi Building Panel can be applied directly to wood or metal studs, over gypsum board (green board or drywall), masonry walls and existing ceramic tile. The recommended thickness for a wall application is 1/2", 5/8", or 1".
The particular thickness is dependent solely upon the desired effect that the contractor wants to achieve. If a contractor is applying wedi Building Panels over a gypsum product, the 1/2" board will most likely be used as this will allow for the trim pieces of ceramic tile to cap where the wedi Building Panels end.




Can I install the wedi Building Panel directly to the studs?

1/2", 5/8" and 1" wedi Building Panels can be fastened directly to wood or metal studs with only a few fasteners per sheet {one (1) wedi Fastener per one (1) ft. of stud}. When the board is applied directly to studs the 5/8" material can be used if the ceramic tile to be applied will have a flush or surface finish. The 1" board can be applied directly to studs if a "floated" look is desired.




Can I install the wedi Building Panel over green board/drywall?

Because the wedi Building Panel is 100% waterproof, it is not necessary to use green board/drywall behind the installation. However, it is common for this material to be applied in wet areas and it has no detrimental effects on the installation if waterproofed with the wedi Building Panel.
Can I use the wedi Building Panel in an exterior application? The wedi Building Panel is not recommended for use in a horizontal exterior application. On a vertical surface, the wedi Building Panel can be used in certain instances. Please contact wedi Technical Service when planning this type of installation.




Can I use the wedi Building Panel in an exterior application?

The wedi Building Panel is not recommended for use in a horizontal exterior application. Please contact wedi Technical Service when planning this type of installation.
On a vertical surface, the wedi Building Panel can be used in certain instances.



How is the wedi Building Panel cut?

The wedi Building Panel is cut with a utility knife, scoring is unnecessary as the blade will be able to penetrate through the board. Mechanical saws and handsaws can also be used.




Do the seams in an installation have to be taped?

Yes, all seams should be taped with a standard fiberglass mesh tape using latex modified thinset mortar to provide a continuous bonding surface. In wet areas wedi Waterproof Sealing Tape or wedi Joint Sealant must be applied. If the sealant is used, no glass mesh tape is needed.




Is the wedi Building Panel strong enough for my ceramic tile installation?

The wedi Building Panel has been rated for heavy-duty commercial use by the Tile Council of North America (TCNA). This means that wedi Building Panels can serve as an underlayment on floors in a residential application such as kitchen or living room floors, in bathrooms or stairways, as well as spaces such as office buildings, breweries or anywhere that there is heavy duty use. When installed on walls, wedi Building Panels can support any standard ceramic tile or natural stone (up to 23 pounds / sqft) . The board will not fail under normal conditions, including moderate impact, such as the weight of an adult person or the blow of a wayward refrigerator.




In wet areas does one have to use the wedi Waterproof Sealing Tape or wedi Joint Sealant?

In wet areas wedi Waterproof Sealing Tape or alternatively wedi Joint Sealant must be applied. Regular silicone caulks must not be used, as mortar will not bond to silicone and these may provide a food source for bacterial growth.




How is the joint tape applied?

All joint tapes should be applied using latex modified thinset mortar.



The wedi Building Panel can be dented when pressure is applied, will this cause problems after ceramic tile is adhered over these dents?

No, once the cells in the foam are broken they will not reinflate. When thinset mortar is spread over these indentations the voids are filled and will set as such.
As long as the wedi Building Panel is not punctured all the way through the foam, the waterproof qualities of the board will remain. In situations where this is unavoidable (such as at the attachment points where nails or screws are used) wedi Waterproof Sealing Tape or wedi Joint Sealant must be applied.




Is the wedi Building Panel's foam toxic?

No, the foam is inert and inorganic. It will not produce carcinogens when handled or cut. It is produced utilizing a CFC-free blowing agent.



The wedi Building Panel is more expensive than the other tile backerboards. Why should I use this product?

In comparing square foot pricing, the wedi Building Panel is more expensive than cement backerboards and fiber-cement boards. However, in comparing value, wedi Building Panel saves extensive labor, provides a waterproof substrate, is less likely to create an environment for mold, is a crack suppressor and weighs 75% less than the other products mentioned. Total job costs are reduced when using wedi Building Panel. Time of installation is faster and easier because it is lightweight, cuts with a utility knife and needs only 1 fastener per square foot. The end result is a waterproof surface.
To achieve a waterproof substrate with cement backerboard or fiber-cement board, a waterproof membrane must be used. The membrane installation costs almost as much as the wedi Building Panels.




What is the wedi Fundo Shower Pan?

The wedi Fundo Shower Pan is a prefabricated, tile ready pan that is installed on a wooden or concrete subfloor using latex modified thinset mortar (1/2" thick). It does not require a shower pan liner underneath the system nor any waterproofing on top. It is already presloped and includes a pressure fitting drain system with no weep holes necessary. It is made of extruded polystyrene foam and is 100% waterproof.




Which wedi Fundo Shower Pan sizes are available?

The wedi Fundo Shower Pan comes in 3'x 3', 3'x 4', 3'x 5', 3'x 6' (offset drain), 4'x 4', 4'x 5', 4'x 6', 4' x 7', 5'x 5', 5'x 6' and 5'x 7' sizes.



Can I cut the wedi Fundo Shower Pan to size?

Yes, using a circular or table saw, the wedi Fundo Shower Pan can be cut to size. The drain is centered so in order to maintain a proper slope layout, the pan should be cut equally on at least two sides. The 1/2" x 1/2" channel along the pan's perimeter always needs to be remade so that the 1/2" wedi Building Panels will fit properly.




Can I extend the wedi Fundo Shower Pans?

Yes, using wedi BALCO Presloped Extension Panels. These panels always need to be connected to the wedi Fundo Shower Pan using a shiplap notch. All wedi shower floor joints have to be prepared with shiplap connections and the wedi Joint Sealant needs to be applied inside the shiplap joint and an additional bead is applied on top of the joints (use a putty knife to smooth the sealant over the joints).




Do local building codes allow the wedi Fundo Shower Pan system to be used instead of a conventional shower pan liner and mortar bed construction?

Yes, your inspection department will recognize: the wedi Fundo Shower Pan system is rated as waterproof per ANSI 118.10 and is certified with IAMPO (File # 4953) and therefore meets all UPC requirements.




How much time does it take to install the wedi Fundo Shower Pan?

A standard size installation, for instance 3' x 5', takes approximately 30 minutes to install. The wedi Fundo Shower Pan is tile ready after being installed on a wooden or concrete subfloor.




Why is a wedi Fundo Shower Pan installation less expensive than traditional shower pan liner-mortar bed construction?

If done properly, the traditional method includes a pre slope, shower pan liner and mortar bed, which easily takes 8 man hours to install, compared to approximately 30 minutes for the wedi Fundo Shower Pan. Depending upon the mortar bed thickness, 2-3 days drying time is often required before installing ceramic tile. The wedi Fundo Shower Pan is tile ready immediately after installation.




Which ceramic tile sizes can be used with the wedi Fundo Shower Pan?

2" x 2" or larger sizes can be installed with modified thinset mortar and cementitious grout. All ceramic tiles less than 2" should be grouted with an epoxy joint filler compound. For commercial applications or where wheelchair use is expected, please contact wedi Technical Service for the appropriate tile formats and setting material recommendations.





Why is the wedi Fundo Shower Pan so much safer than a conventional concrete shower pan?

The only way to safely install a conventional concrete shower pan is to apply waterproofing on top of the pan (liquid membranes on concrete bases often crack). However, a preslope is typically installed underneath the shower pan bed and pan liner, which allows water to run towards the weep hole drain. This process is unpredictable and water may simply remain sitting in the porous concrete weep holes clogged) and cause mold growth.
Mortar bed shower pans often fail since the pan liner is sandwiched between the layers of concrete which can result in tears that cannot be seen or easily repaired (tears often occur especially where the pan liner is tightly installed over the curb and applied in a multi-corner fashion). Another concern is the watertight installation of the pan liner toward the drain flange. Since the pan liner is nailed directly to the studs, leaks can occur if the fasteners penetrate it. The wedi Fundo Shower Pan does not absorb any water like concrete and completely protects any substrates from water exposure.




Can I use the wedi Fundo Shower Pan with any other ceramic tile backerboard other than the wedi Building Panel?

No, the wedi Fundo Shower Pan is part of a complete system. Building codes require a waterproof membrane-pan liner to protect the shower wall including curb 4" to 6" high. Although a pan liner is not needed underneath the wedi Fundo Shower Pan, waterproofing is necessary in order to meet the 4"- 6" wall requirement. This is done by using the waterproof wedi Building Panel with all seams being sealed with wedi Joint Sealant in between the board joints and the channel connection of the wedi Fundo Shower Pan, Building Panels and Curb.




How do I instruct the plumber to setup the drain system before installing the wedi Fundo Shower Pan and pressure fit drain assembly?

A 2" ABS or PVC pipe (per ASTM standards) needs to be installed where the drain is located. The 2" pipe is cut flush to the surface of the subfloor. The trap is securely mounted underneath the subfloor so that the pipe and trap can carry water without moving. A hole 5" in diameter must then be cut around the 2" pipe to allow for installation of the wedi Fundo Shower Pan-drain assembly. The plumbercould also install a 2" pipe after the wedi installation if access is available from below. If a Cast Iron drain is existing, please contact wedi for a fitting sealing gasket which we will provide.




What is the height of the wedi Fundo Shower Pan?

The height at the exterior edge is between 1 1/2" and 1 3/4".