Sloping a concrete patio or walkway is critical to provide the drainage it needs. Concrete that is not sloped properly will not drain. This is great news for mosquitos, who will use pooling water as a breeding ground. And concrete that slopes toward your home, instead of away, can lead to rot and mold. The lesson: Before beginning a new project, make sure to account for proper drainage.
The standard slope for proper concrete drainage is a one-quarter inch drop for every foot of length. So, to calculate the difference in height between one end of a patio or walkway and another, simply multiply the length by one-quarter. This means the end of a patio protruding 10-feet from a home will drop two and a half inches from the starting point.
Oftentimes, a walkway will naturally tilt away from a home or other structure. But if it doesn’t, you need to account for proper slope to avoid water damage. A 4-foot wide concrete walkway that runs parallel to a house should drop one inch away from the home. If it’s running perpendicular to a structure, follow the one-quarter inch pitch for every foot of length rule. This will ensure water isn’t an unwelcome guest at your front door.
Now, a caveat: One-quarter inch drop per foot is the standard measurement for concrete drainage. Depending on the surrounding conditions and the expected amount of precipitation, the slope can range from one-eighth to three-eighths per foot. In a drier climate? You can likely get by with one-eighth. Really wet climates may call for three-eighths per foot for proper drainage.
The surface’s exposure to sunlight and heat can impact the amount of slope as well. A sunbathed patio on the south or west side of your home will, of course, dry faster than a shaded concrete surface.
Alright, so there are a few conditions to consider when planning for concrete drainage. But—in addition to the amount of slope required for proper concrete drainage—there is the way in which a patio slopes to consider. Existing conditions like landscaping and neighboring properties will, in large part, dictate the direction in which a patio needs to slope for proper drainage (other than away from any structures). The goal is to ensure water sheds away from buildings or toward any drains.
The takeaway? Carefully consider the expected precipitation, existing conditions and surrounding properties in order to ensure a finished concrete patio drains properly. Your efforts will not be in vain. A thoughtfully constructed patio or walkway that sheds concrete-corroding water will last for years.
In order to properly slope a concrete patio or walkway, simply pitch the forming according to the above calculations. Done and done . . .
This is all fine if you are planning a new project, but what if you’re stuck with a patio or walkway that doesn’t slope, or cants the wrong way? Unfortunately, the best solution to this problem is to remove and redo the concrete.
The good news? Intermountain Concrete Specialties has the knowledge, products and equipment needed to help with any of your DIY project needs. And with seven locations from St. George to Idaho Falls, help is never far away.
Tilt-up concrete construction has become the building method of choice for large-scale projects such as retail stores, schools, apartment and office buildings, warehouses, commercial structures, and even residential homes. Used since the early 20th century, tilt-up is a construction method where huge concrete panels are cast on site and then lifted up into position—think barn raising but with concrete instead of wood. Today, tilt-up concrete construction is used on virtually every type of large building project, due to reasonable cost, durability, and construction speed.
Much of the effort happens up front during planning, site layout and evaluation. This helps ensure that proper procedures and methods are followed, and that a safety perimeter is established for the actual lift. A flat work site is best (although not always possible) as the huge concrete panels are cast on site. Typically, wall forming occurs while laid out on the foundation of the building or on a temporary casting slab.
It’s not uncommon to lay the exterior façade, such as brick, on the cast concrete panels before tilt up occurs. If no façade is laid, a release agent is applied to the slab after proper curing. This helps the panels lift easier without breaking.
Steel reinforcements are installed in a grid pattern to add structural integrity to the concrete panels. Lifting/bracing sensors are secured to the reinforcements. A vibrator ensures even concrete placement throughout the panel. Contractors use laser screeds to improve the quality of casting slabs, and ride-on trowels to give the surface a smooth finish. Tilt-up forms are then laid out and measured precisely with laser technology. Engineering inspections occur at every step of the process.
Upon curing, formwork is stripped from the panels and prepared for tilt up with appropriate lifting mechanisms, clutches and cables. Safety briefings are critical prior to lift, and one person is usually assigned to communicate with the crane operator. After an engineering inspection, the tilt-up crew guides the concrete panel into position and adds structural shims after precise measurements and placement are confirmed. Temporary braces hold each panel in place as others are raised.
Once all of the concrete panels have been lifted and secured, the project engineer inspects and signs off on the tilt-up construction so the building exterior and interior can be completed.
Product and Equipment Innovations
The growth of the concrete tilt-up construction industry has led to many product, method and equipment innovations. Lifting inserts, braces, brace anchors, aluminum strong backs, rear supports, dobie, bolsters and spacers, bondbreakers, ground release and gyro tilt systems are just a few of the products available to ensure safe, efficient lifting and placement of the massive concrete panels.
As experts in tilt-up concrete construction, we offer tens of thousands of products, vast project knowledge, and a continuous history of construction innovation. No job is too large or too small. Call Intermountain Concrete Specialties today at 801.486.5311 for the products and support you need for your next tilt-up concrete construction project.