Driveways
Concrete
Concrete produces a nice, hard, clean surface to walk and park upon.
Construction
Most exterior slab systems are a standard 4” thick. A base of 4-6” of compacted crushed gravel supports the slab. Installers strengthen the slabs with wire or rebar in order to support heavier loads. Producing concrete flatwork with a nice-looking surface finish requires experience and high levels of skill. Installers only get one shot at doing it right and failures can be extremely time consuming and expensive to correct. Bravo to the professional men and women who do this work.
Drainage
Good drainage helps to protect your home’s concrete flatwork. Concrete floors, porches, patios, driveways, garage floors, and sidewalks all depend on good drainage for durability. Concrete will move and crack in response to expansion and contraction of the soils under the slab system. This movement is minimized by preventing moisture from reaching the soils around and under the slab system.
NOTE It is a good idea to avoid washing exterior slabs with cold water when temperatures are high with direct sun on the concrete. The abrupt change in temperature can sometimes damage the surface of the concrete. It also wastes water. Washing of slabs can also increase soil movement by allowing water to penetrate any existing cracks and find its way to the underlying soil. I recommend sweeping or blowing to keep exterior concrete clean. If washing is necessary, do this when temperatures are moderate.
Cracking
The nature of concrete is it cracks. Concrete slabs shrink about ½ inch every 10 feet or so as it cures. Some of this shrinkage shows up as cracks. Cracking of concrete flatwork also results from temperature changes that cause expansion and contraction. As cracks occur, it is good to seal exterior slabs with a waterproof concrete caulk (available at hardware or home improvement stores) to prevent moisture from penetrating to the soil beneath. For indoor slabs that do not get rained upon this is less important. Do not permit extremely heavy vehicles such as moving vans or large trucks to drive on your concrete flatwork.
Care
Driving or parking on slabs with snow creates ice. So it is advisable to remove snow promptly before it has a chance to become compacted ice. De-icing agents, such as road salt and other chemical agents can affect the surface. Pet urine, fertilizers and radiator coolant overflows are all things that can damage or cause spalling of concrete. Concrete sealers are available at paint or hardware stores and can be applied prior to the winter months. Sealers will help protect your outside and garage concrete flatwork from the damaging effects of rain and road salt. Garage slabs can be coated in pleasing ways but the preparation and application of the coatings are critical for a good result. Concrete slabs vary in color due to color differences of the concrete from one truck to the next overtime the sun will bleach the concrete to a consistent color.
Asphalt
An asphalt driveway is a petroleum-based product made with aggregates and sand. Asphalt is hot, soft and pliable when first installed. It hardens when rolled with a heavy machine and as it cools. Fresh installations require protection from things that might damage it (scraping, gouging, scuffing) until the material is cured .
Spills
Over time, the effects of weather and earth movements can cause minor settling and cracking . Chemical spills on asphalt must be avoided. Gasoline, diesel, oil, turpentine, and various other solvents can dissolve or damage the surface. Absorb such spills quickly with litter the wash with soap and water. Rinse it afterward thoroughly with plain water.
Heavy loads
Avoid any concentrated or prolonged loads on your asphalt, particularly in hot weather. Turning front wheels or “peeling out” will permanently scuff hot asphalt. High- heeled shoes, motorcycle or bicycle kickstands and trailers jacks can cause damage. Even cars left in the same spot for long periods can create tire depressions in asphalt. Avoid heavy, industrial type heavy trucks on your driveway because it was likely designed for lighter use only.
Aging
Exposure to sunlight and other weather conditions will fade your driveway and make the surface gravel material more visible. Over time, your asphalt driveway may begin cracking. Cracks allow water to penetrate and assault the driveway base. You should seal any cracks before they have a chance to worsen and cause permanent damage. For sealing asphalt driveways, use a dilute asphalt emulsion, rather than the more common coal tar sealant. Sections with cracks that exceed 1/2inch in width should be removed, patched and repaired.
Pavers
Think cobblestones from medieval times and you basically have the idea.
Description
Cobblestone type pavers come in a wide variety of shapes, colors and sizes. Pavers are from 3”-6” thick and require varying amounts of base (similar to concrete) depending on the load they will be required to support. Pavers have lots of joints, so porosity and small movements do not cause cracking problems and are of no concern.
Installation
Proper preparation of the underlying soil, as well as the installation of base layers and the final paver material is critical for a quality result. Establishing solid outside borders is critical. An even compaction of the base material is also extremely important. Erosion of the base can cause pavers to lift, loosen and settle lifetime installation. Check out just about any old town in Europe for proof.
