Mastic

Mastic is a key part of any builder’s or DIYer’s toolkit when it comes to sealing and weatherproofing. Whether you’re filling gaps around windows and doors, sealing joints in panels, or pointing cracks, a good mastic keeps moisture, wind, and dirt out, helping your work last longer and look cleaner. It’s flexible, too, which means it can handle the usual expansion and movement that comes with building materials without cracking or losing its grip.