There’s a foam called expansion joint foam – we typically buy it from our local concrete company – they should carry it near you as well. It’s about 1/2″ thick and 4″ tall – has a removable top piece, about 1″ to create the gap where you put the SikaFlex Self Leveling Sealant you can purchase at Home Depot for the waterproofing of the joint.[amazon_link asins=’B000KKOO5M,B004WAPFS6′ template=’ProductCarousel’ store=’asthpogu-20′ marketplace=’US’ link_id=’ecf518cc-74d9-4b4c-8f34-666a54df1e87′]