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