Asphalt expands and contracts. Cracks are at their widest in the winter months. To prevent water, subsequent freezing and deterioration of your asphalt surface, keep a bottle of pourable crack filler on hand and drizzle the crackfiller into the cracks periodically as you see them separate. Pourable Crack Filler is available for about $18 at local hardware stores. Lauer & Sons recommends SealMaster products and can supply pourable crack filler (1 gallon) at cost as part of our driveway maintenance service.