What is Tiledek?
Duradek Tiledek is a 60 mil thick, PVC roofing membrane similar to Duradek “Ultra”. It is designed to have outdoor porcelain tile or slate installed over top of it with a thinset mortar bond coat. Lightweight concrete or cementitious finishes can also be installed over it. From here on we will just refer to the overlay products as ’tile’.
A fabric has been laminated to the topside of the roofing membrane to provide for a strong physical “grab” by the thinset mortar. Tiledek is only available as a “professionally installed waterproofing system” through the network of trained Duradek applicating contractors all over North America.
Is an outdoor tile application waterproof by itself?
Absolutely not! It is absolutely certain that water will get under the tile. That is precisely why there are so many problems with outdoor tile decks. People THINK – and are even misled to believe – that a tile installation is waterproof and therefore they don’t pay too much attention to the proper waterproof treatment underneath.
The failures are often waterproofing failures where leaks that have been happening undiscovered for years eventually cause rot requiring major renovation work. In these situations, not only does the structure need replacement work, the tile application must be torn up to get at it. The water will most likely enter through cracked grout joints or on the perimeters. If the tile cracks, water will enter. If the deck is in a cold climate, the moisture freezes, expands, and may cause tiles to erupt.
With Tiledek, a failure at the tile surface doesn’t mean the waterproofing system has failed. If the membrane is intact and performing its function of keeping the water out, replacing a cracked or erupted tile or a cracked grout joint is relatively easy and inexpensive.
What are Tiledek’s credentials?
Tiledek is a variation of Duradek Ultra, the first PVC walking roof deck material on the market. Duradek Ultra has been installed for over 40 years and has proven itself in all climatic regions of North America. Tiledek has been evaluated and tested to industry standards and meets most North America Building Codes. For detailed information, please see the Tiledek Approvals page on our website.
How is tile usually installed on decks and balconies?
There are two distinct methods of installing tile in waterproof applications: thickset (using a 1-1/2 inch “dry mud bed”) and thinset (using a 1/4 inch acrylic modified mortar).
Thickset: Thickbed installations are based on the traditional method of packing a mortar bed over a surface before installing the tile. The tile is adhered to the mortar bed either while the mortar bed is green (just beginning to dry) or after the mortar bed has cured. The thickset method is more likely to be used where the tile is thick and irregular in order to achieve a flat walking surface.
Thinset: Thinset mortar is a blend of cement, very finely graded sand, and a water retention compound that allows the cement to properly hydrate. Tile set by the thinset method is adhered to the substrate with a thin layer of “thinset” mortar. This type of cement is designed to adhere well in a thin layer – typically not greater than 3/16th thick. Only “gauged” tiles (with similar thickness) should be used in thinset mortar applications. Medium-set: Medium-set mortars can be used to adjust for slightly larger variations in the substrate than can be accommodated with thinset mortar. They are also used with large, heavy, thick or “ungauged” (varying thickness) tiles, where a thicker setting bed and a coarser aggregate may be required to achieve a flat installation and to support the weight of the tile while the cement is curing.
What does Tiledek compete with?
The answer to this question depends upon the deck being over living space or not. Obviously if it is over living quarters, then the membrane must be a roofing membrane and more importantly, it must be installed with roofing principles in mind. Should the deck not be over living quarters, there might be no building code requirement that the membrane is a roofing product but the installation details should be no less stringent considering the consequences of leaks. Water intrusion can cause very expensive damage to the structure and we believe all waterproofing jobs demand the attention of a professional. For the purposes of this discussion, we will separately deal with roofing and non-roofing applications.
For Roofing Purposes: Torch applied or self-adhering modified bitumen roofing materials: Modified Bitumen (MB) is asphalt that has had modifiers added to it to give it plastic or rubber-like properties. The most common types of modifiers being used are APP (Atactic Polypropylene) and SBS (Styrene Butadiene Styrene). To the best of our knowledge, none of the manufacturers of Modified Bitumen materials supports tile installations over top of the roof membrane and therefore provide no promise that it works and certainly no guarantee. In addition, the asphalt in these products is not compatible with the mortar in the thinset or the grout lines and may bleed through causing a discoloration. More importantly, when the MB softens as it heats up it can be compressed and may allow the tile or the grouting to crack from the movement from traffic on top. Any product that is designed to have tile installed over top will have test results from the Robinson test (ASTM C627) to verify it is capable of supporting weight of people and equipment.
Note: In Canada, on wood framed structures (part 9 of the National Building Code) all decks and balconies are required to use an approved roofing membrane.
Non-Roofing Applications (referred to as “waterproofing” membranes): The first thing you will notice when researching the products that are available for waterproofing decks and balconies to which tile will be applied is the lack of the word “roofing”. Most manufacturers of these systems want nothing to do with the details, the headaches and the liabilities involved in roofing. You will notice details that we would not even consider using in a non-roofing application (such as finishing a membrane on the flat horizontal surface without turning it over the edge and then caulking the leading edge). Most of the details you see are for concrete decks and balconies, not for the wood frame construction.
Why is Tiledek superior to the alternatives?
As you can tell from the extensive list of other products that are available for “waterproof’ applications under tile, there are very few who claim to be roofing products. Most of the details on the websites of the products are meant for waterproofing concrete balconies and ARE NOT an “apples to apples” comparison to the kind of waterproofing we do with our materials. We treat each and every deck as if it was a roof and we detail accordingly. It doesn’t take much of a study to see how superior our details are. But the most significant reason why Tiledek is superior to all the other alternatives is the network of professional applicators that install the product.
Duradek (and therefore Tiledek) is only sold through a network of businesses that have been trained. There is no other way to get the product installed. That means huge protection for the building owner. THE MOST IMPORTANT PART OF THE PROCESS IS THE CONTRACTOR WHO CARES ABOUT DOING IT RIGHT. Our primary responsibility is to protect the building from water finding its way in. Regardless of the success or possible failure of the tile overlay, we can GUARANTEE our customers that their home will be protected from water damage.
How is Tiledek installed?
Tiledek is installed using almost identical techniques to the installation of Duradek. We use the same adhesives, heat welded seams, and waterproofing details. There are few finish details that differ due to the tile that will be installed after we are done. Here are the areas that require different techniques:
Outside Perimeters: As with regular Duradek, there are many ways to finish the outside perimeter of a tile deck. As waterproofers, we need to establish what “look” the owner wants to be able to advise them properly. You should consult with both the builder and the tile setter to discuss the perimeter finish details. Depending upon their desired finish, we can alter our detailing. This is an area where we can offer our customers excellent service and help them make good waterproofing decisions while taking all the future steps they will go through into consideration. Our attention to these details contributes to the overall success of the job.
Drains: Should drains be necessary, we cannot use our regular WDD1 system. We recommend a special cast drain with a square top to make it easier and more attractive for the tile applicator to finish to.
Rail Attachments: We strongly recommend attaching rails to the fascia instead of the surface of the deck. DO NOT INSTALL RAILS OVER TOP OF TILE AS IT WILL CAUSE THE OVERLAY TO CRACK. We have special details for surface mounted rails if there is no other alternative.
Inside Perimeter: If the owner wants the tile to return up the wall as part of their finished look, appropriate flashings are needed. If not, then consideration must be given to the visibility of the part of the membrane that returns up the wall and hiding the gap that must be left on the inside of the tile application.
Surface Preparation: Apart from a thorough inspection for a properly fastened substrate, there is little prep work necessary. A light sanding of the joints of the cement board or a scraping of the entire surface to take care of any bumps will suffice. No filling is required.
Who installs Tiledek?
Tiledek can only be installed by a qualified Duradek applicator who has gone through our training program and who works for an authorized Duradek applicating contractor. That is how we can give our customers superior protection in making sure it is done right.
How do you build a deck to make it ready for tile?
A major cause of failure of tile over decks and balconies is that the structure to which it is applied allows too much deflection. Tile has little tolerance for deflection. Cracking grout lines or tile is the result of deflection. Deflection (the spring or give of the deck surface) is a product of the joist spacing and thickness of the flooring materials.
The TTMAC specification for flooring under tile or slate is as follows: 3/4 inch plywood fastened with 2 inch #10 Exterior Wood Screws @ 6 inch oc @ perimeter and 8 inch oc @ joists covered with 1/2 inch cement board secured with thinset and fasteners. (The deck must have slope built in – suggested slope 1/4 inch per foot).
The use of a cement board overlay is required/recommended by tile associations and manufacturers. Cement board, unlike plywood, is not affected by varying levels of moisture. We strongly recommend that decks be built to this specification. For the money that is being invested in the whole system, it would seem unwise to scrimp on the subsurface. In case of a failure (cracking), the first thing anyone will look at (and blame it on) is whether the floor was strong enough and provided the necessary deflection resistance.
Concrete decks and balconies are suitable for tile application but still require proper waterproofing or roofing protection. We recommend you follow the local best practice guidelines as laid out by the Tile Contractors Association of TTMAC or the building code. There may be regional differences in the suggested use of cement board or a second layer of plywood. As with all the details involved with a tile deck over a wood structure, you should follow the tile and thinset mortar manufacturer’s specifications.
Can tile be applied over an existing deck?
Most existing deck surfaces (PVC membrane or liquid applied finishes) are applied to 5/8 inch or 3/4 inch plywood and therefore are not suitable for a tile overlay without some stiffening to reduce the deflection. The vinyl could be removed (possibly leaving the existing vinyl up the wall behind the siding and building paper), the floor stiffened with the appropriate thickness of cement board and the Tiledek installed over top.
There is another system that can be used to stiffen the existing structure. Schluter’s Ditra mat can be installed over top of Tiledek (with thinset) and then the tile can be installed over top of Ditra. The Ditra mat stiffens the floor system to an appropriate level to provide for residential use of tile. We have tested this system with the Robinson Floor test and achieved a “residential” result.
How do you clean Tiledek if necessary?
If Tiledek has been left exposed to traffic and construction debris prior to tiles being laid and needs to be cleaned, it can be cleaned easily and effectively. Pressure washing with a light (1500 psi) spray with the nozzle no closer than 6 inches from the surface will work well. The surface can also be washed and lightly scrubbed with a bristle broom and hosed off.
What is the warranty with Tiledek?
Tiledek is covered with the same waterproof warranty as Duradek Ultra – 10 years. See the full sample of the Tiledek warranty for the specific terms and conditions.
Does the surface need to be sloped?
Yes! Sound roofing/waterproofing practice needs to be employed even when tile is applied over top. We operate on the expectation of water getting through the tile installation. Our membrane will be applied to a surface sloped towards drains, scuppers or an outside edge which allows the water to escape. Moisture will still run downhill, even under tile applications. This can happen without negatively affecting the bond of the thinset mortar to the tile or the membrane. We recommend the seams of the Tiledek run parallel to the slope to avoid any water puddling up behind the bump.
Do we recommend tile installations in cold climates?
We do not profess to be tile experts. Manufacturers of the tile and the installation accessories must answer this question. We are waterproofing professionals. We can protect the structure from water damage no matter how hot or cold or wet the climate is. And we can provide a membrane to which thinset mortars will tenaciously adhere. We cannot (and do not) guarantee tiles will not erupt as a result of freezing temperatures but we can (and do) guarantee the water that gets under the tile will not get into the building. There are currently countless decks and balconies in cold climates being overlaid with tile. People like the look and are going to continue to use it regardless of if it is a good idea. Our part is to make sure they don’t suffer water damage.
Is Tiledek an anti-fracture membrane?
Tiledek will add a very small amount of fracture resistance to the system but should not be purchased as an anti-fracture membrane. Because it is glued to the subsurface, movement beneath the Tiledek membrane may transfer through into the tile.
Does Tiledek pass the Robinson Floor test?
We had our material tested to ASTM C627 (the Robinson Floor Test) to see how suitable our system was for application under tile. Tile has very little tolerance for any deflection or movement of the surface to which it is installed. Too much deflection or if the membrane beneath is too soft may cause cracking of the gout lines or the tile. Tested over 3/4 inch plywood and 1/2 cement board, porcelain tile on Tiledek achieved a “heavy” rating with no cracking of tile or grout lines after 9000 revolutions with 600 pounds on steel wheels (on the twelfth cycle). This is much more than would ever be necessary for residential traffic on a roof deck.
On the same subsurface assembly, we achieved a “residential” rating on slate. There were no signs of cracking on the slate or the grout line. The failure was in the slate itself which showed signs of the surface deteriorating where the steel wheels made contact. On 3/4 inch plywood covered with Tiledek plus a layer of Schluter’s Ditra mat, we achieved a “residential” rating.