Serving Western Washington Since 1979.
Planning and Preparation
Before you begin your project, it is important to properly plan and prepare. Proper planning will save time in the end, and helps to assure your satisfaction with the product. If you are unsure of how much concrete you need or if the area is suitable for concrete, give Cascade Mobile Mix Concrete & Line Pumping a call today at 253-847-9119. Our staff is experienced in all types of concrete pouring situations and will answer all of your questions.
For common household projects - driveways, walkways, and patios – 4 inches thick should do the trick. Thicker concrete (i.e. 6" is recommended for heavy-duty use or heavy vehicles) It is recommended to use a ¾ minus crushed gravel compacted base. You can get a compactor from a rental equipment store. Drainage industry standard calls for a slope of ¼ inch per foot away from structures. Some projects may be able to use ⅛ inch slope.
While taking care to only dig as deep as necessary (keeping an eye out for power lines; if you are unsure where lines are, call your utilities for a locator), ensure you remove tree roots, leaves, wood and any other organic matter in the desired area.
Install expansion joint material anywhere concrete will come into contact with existing slabs, steps or buildings. The expansion joint should reach the bottom of the slab; this ensures the new slab will be separated from existing structures.
Now that you have your planning down, we suggest you review our Concrete Calculator to determine your exact needs.
Specifying the correct mix for your job can be the difference between long-term satisfaction and disaster. Concrete specifications consist of strength (PSI), slump (thickness) and chemical additives.
Concrete Exposed to freezing and thawing temperatures should have a compression strength of 3000 psi and have at least 5% entrained air (+/- 1.5%). Air entrainment allows for the expanded water when frozen to travel into the air voids created by the air additive. Without the air, concrete is at risk for cracking.
For our environment, we recommend a slump of 4 inches (+/- 1"). Note: a slump greater than 4" may prolong the time you have to wait before finishing, particularly in cool weather. It will also increase the tendency for shrinkage cracking.
Will ensure your slab won't settle or vary in thickness, make sure to compact the soil/gravel base in the desired area.
Take care to stake your forms securely to the ground, while paying close attention to the slope (for proper drainage). 2x4s are perfectly adequate for use as forms; though make sure you have the desired thickness (usually 4") available at the edges.
In addition to air entraining admixtures, chemical additives may be used to accelerate or retard setting, reduce water or plasticize the concrete.
Cascade Mobile Mix Concrete & Line Pumping's concrete is a high-quality concrete and we run a plasticizer in our concrete unless requested not too.