Each sealant has its own specific properties and limits that need to be known to avoid failures or overloading.

When deciding which sealant to use, we need to know whether it adheres to the material we want to seal, what the requirements are in terms of elasticity, tensile strength, temperature resistance, whether it is the right colour or whether it is paintable. Finally, of course, price is important.

If the 8-step rule is followed, the joint will be well sealed and the watertight.

First, we need to check that we have all the materials we need to do the job well:

Step 1

The surface of the joint must be hard, clean, dust and fat free. Some sealants need to be applied to a dry surface. Remove any chipped or poorly bonded components. 

Step 2

Insert a backfilling tape of the appropriate diameter into the joint to achieve the optimum elastic properties of the sealant. The backfilling tape allows the sealant to adhere only to the sides of the joint and to correctly size the joint. The diameter of the backfilling tape must be equal to or larger than the joint. It is inserted at a suitable depth with a blunt object to avoid damage the cells. This results in a correctly dimensioned joint.

A correctly dimensioned joint is made in the following ratio:
joint width : joint depth = 2 : 1, maximum 1 : 1.

The minimum width of the joint is 6 mm, the maximum 20 mm.

Step 3

If you want neatly made joints, tape the edges of the joints with self-adhesive protective tape. For better adhesion to porous substrates, we recommend using a primer. The instructions in the datasheet must be followed.

Step 4

Cut off the cartridge at the top of the thread. Be careful not to cut too much thread. Screw on a tip which is cut diagonally to the width of the joint, slightly less than the width of the joint.
Insert the cartridge into a manual or pneumatic gun. 

Step 5

Apply the sealant as evenly as possible. When interrupting work or replacing the cartridge, loosen the handle on the manual gun and pull the piston back.

Step 6

Moisten the sealant and the smoothing tool TKK SEAL SMOOTHING TOOL with smoothing agent TKK SEAL SMOOTHING AGENT. Straighten and remove excess sealant before the skin is made. It is very important to press the sealant well on the surface to be sealed. By smoothing, we improve the adhesion of the sealant to the surface by 50%.

Step 7

Immediately remove the protective tape before the sealant begins to harden. If the mass has moved away from the edge of the joint, it can still be smoothed.

Step 8

The fresh compound and the tool are cleaned with TKK CLEAN PROTECT ACTIVE CLEANER, while the hardened mass can only be removed mechanically.

To facilitate the calculation of the sealant consumption according to the width and depth of the joint, we have prepared the table below:

Example of appropriate selection of elastic sealant TKK for expansion joints of dimensions from 6 mm to 20 mm:

Facade joints
Sealant: TKK SEAL FLEXIBLE JOINTS WALL,
primer TKK SEAL SILICONE & HYBRID PRIMER,
appropriate dimension TKK SEAL BACKFILLING TAPE.

Loaded floor joints
Sealant: TKK SEAL FLEXIBLE SEAL & BOND,
primer TKK SEAL SILICONE & HYBRID PRIMER,
appropriate dimension TKK SEAL BACKFILLING TAPE.

Terraces, balconies
Sealant TKK SEAL FLEXIBLE SEAL & BOND or TKK SEAL ALL PURPOSE SILICONE EXTRA,
primer TKK SEAL SILICONE & HYBRID PRIMER,
appropriate dimension TKK SEAL BACKFILLING TAPE.