The GreenJacket material must be clean and dry. Reinforced tabs have a pressure sensitive adhesive backing. Pressure MUST be applied to secure them properly. Also if temperatures are 41°F or colder, you may need to warm up the adhesive backing to have them stick and secure properly. This can be done by the use of a hot air gun or by keeping the tabs in the cab of your truck warm until needed. Tabs are installed at MAXIMUM 4ft spacing around the perimeter edge of the cover. Do not place Reinforced Tabs and Nail stakes on a seam. If in a windy location you can increase tabs to every 2 feet for greater hold down. Since the GreenJacket comes new with the required amount based on every 4ft, you will need to order the additional amount for the windy location.