Things to Avoid When Using SBS-Modified Products

Things to avoid When Using SBS-Modified Products

There are a lot of do’s and dont’s when it comes to using self-adhering waterproofing membranes that utilize an SBS-modified adhesive system. Failure to adhere to these general rules can potentially lead to a huge problem for you, your reputation, and cost to correct the problem.

General Rules to Avoid:

  • Roof work is dangerous - always follow strict safety protocols when working or walking a self-adhered underlayment - film surface underlayments pose the most risk for slippage when wet or covered with dew.

  • DO NOT install over PVC, TPO or EPDM roofing materials - these roofing materials contain plasticizers which, when in contact with the asphalt adhesive, will dissolve the mastic and cause it to liquefy - not only does it degrade the waterproofing properties of the mastic, but it has the potential to leak out onto the structure.

  • DO NOT install over silicone caulking, or uncured solvents or sealants - again, the plasticizers will liquefy the mastic leading to a mess

  • DO NOT install on plank or tongue-and-groove boards that are not cured - uncured wood contains tree resins which have the potential to also liquefy the mastic causing run-out.

  • SBS membranes are vapor barriers - always ensure proper ventilation to avoid moisture build-up within attics, wall cavities, etc., leading to hazardous mold growth.

  • MFM products list UV Ratings - when a product is left exposed to the elements for longer than the UV rating, the membrane will lose its waterproofing properties - ensure that the product is covered well within the published time.

  • Minimum Installation Temperature - all of our products list a minimum installation temperature - this means the surface, air and membrane temperature - installing below this minimum can lead to adhesion problems - there are special steps that can be used as outlined on our website for cold weather installations.

  • DO NOT pull or twist the membrane - during installation, it is important not to pull, stretch or twist the membrane into place - this has the potential for the membrane to form “mole runs” or sections where the membrane is not secured to the substrate - mole runs can lead to water leaks.

By following these simple guidelines, you should avoid any disastrous situations when working and installing self-adhered SBS-modified waterproofing membranes. If you have any questions, please contact:

MFM Technical Services
800-882-7663
info@mfmbp.com