Sika Thoroseal® Plus Concrete & Masonry Waterproofer

Founded more than a century ago in Switzerland, Sika has become a global leader in construction chemicals, operating in more than 100 countries. The company is recognized for its innovation and reliability in waterproofing, sealing, bonding, damping, reinforcing and protecting building materials. With a strong focus on sustainability and performance, Sika products are trusted by professionals across both residential and commercial construction sectors. 

Drawing from its deep expertise in moisture control, Sika delivers proven technology to the job site with Sika Thoroseal® Plus Concrete & Masonry Waterproofer. This cement-based formula creates a robust barrier against water intrusion, even under hydrostatic pressure. It’s ideal for concrete, brick, block and stone, performing reliably above or below grade, indoors or out. 

Application is straightforward: Just add water and mix. The first coat is brushed on to fill surface cracks; the second can be brushed or sprayed for complete coverage. The product adheres to damp surfaces, resists mold and acid rain and stands up to freeze-and-thaw cycles. One 35-pound pail covers up to 160 square feet with the first coat and 320 square feet with the second. Working time is about 30 to 40 minutes. Check out Sika’s how-to video for a quick product demo—click here to view it. 

We provided samples to a local homebuilder, who confirmed the product performed as expected and noted it is commonly used in the South. Retailers located in areas prone to heavy rainfall, high humidity or freeze-and-thaw conditions—such as the Southeast, Pacific Northwest and Midwest—should consider stocking it. With its ease of application and pro-grade performance, it’s a great fit for both contractors and DIYers.