Treating Static vs Dynamic Joints

 

The difference between static & dynamic joints

Static cracks and control joints are non-moving parts, which makes them easier to work with during installation. Dynamic cracks and expansion joints, however, are moving parts and need much more attention. Let’s take a look at some of the differences between static joints and dynamic joints.

Start with thorough preparation

Of course, all substrates must be structurally sound and free from any contaminants that may inhibit bond, including oil, grease, dust, paint, sealers, floor finishes, curing compounds, adhesives, etc. For the specific treatment of joints, follow the appropriate industry standards and the flooring manufacturer’s recommendations. The first step, regardless of whether it’s a static or dynamic joint, is to remove any dirt, debris or existing sealant. 

Apply the filler

Once the cracks or joints have been thoroughly cleaned, apply TEC^® Joint/Crack Filler. Follow product data sheet instructions for proper installation. Joint/Crack Filler works on cracks up to 2” deep and 2” wide. Once the product loses tack and is shaved, it is ready for further surface prep or adhesives.

Be especially aware of dynamic joints

Expansion joints and dynamic cracks are treated differently. Coat the cavity with LiquiDam™ using a paint brush and allow it to cure.. Then, fill the joints with sand or a backer rod while leaving the top of the joint open for proper treatment with a sealant. 

Remember that expansion joints are going to move since they’re designed to expand and contract with the concrete. You cannot pour a self-leveling underlayment directly over one. You also can’t tile or apply patch directly over an expansion joint because sooner or later that crack will go through to the surface. 

 

This is an example of what can happen when you don’t honor the movement joints.

 

Once you’ve treated the dynamic joint, you’ll need to add the same soft joint throughout the entire installation. You can either line up the grout joint lines or cut the tile to fit the expansion joint through the entire tile installation. However you choose to do it, dynamic and expansion joints demand your attention to avoid future problems.

Crack isolation membrane over saw cut and static joints

One other option to consider for static and saw cut joints is to apply a crack isolation membrane, HydraFlex™. Without this membrane, any tile installed over saw-cut joints is normally at risk because eventually it will lead to a crack. HydraFlex provides assurance and flexibility for architects, contractors and customers to be less concerned that saw cut joints or static cracks will transfer through the tile. 

Need some technical advice or product information? Contact our Technical Services Team for answers. You can also call 1-800-832-9023, Mon-Fri 7 a.m. - 6 p.m. CST.