Sidewalks Give Life to Portland
When you think about public spaces, parks and squares are the first ones to come to mind. In the past, our children would play in the streets, people would meet and conduct everyday business on them. After the car, we were relegated to more private spaces. Sidewalks remain a proud testament to community life and how people interact with their city. From the beautiful brick sidewalks in downtown Portland, to the sturdy concrete sidewalks in the suburbs, the flavor of these public areas speaks not only of the property owner, but of all of us as Portlanders.
Getting It Right from the Start
When it comes to sidewalk construction, the most important factor is ground preparation. When the ground loses water it tends to shrink, which can cause the slabs to crack or sink. An uneven surface will give irregular support to the sidewalk and there is a good chance of problems down the line. A properly constructed sidewalk should last from 20 to 40 years! However, it is common to see cracked and “hugged” sidewalks as a result of substandard preparation.
The subgrade is the original ground where the sidewalk will be constructed. The subgrade should be compacted and graded to give it a regular surface. The sub-base is a layer, usually of sand or gravel, that allows good drainage, does not shrink, and can be easily compacted. The use of a sub-base can dramatically increase the life of a sidewalk.
Forms ― the wooden structures that will hold the concrete ―, need to be measured twice, as the saying goes. Form regularity is critical to ensure a quality result. Uneven and crooked sidewalks are not only an eyesore, but are prone to cracking.
As with any other large concrete project, control joints should be cut regularly. Large concrete areas will expand and contract over time: joints prevent cracking. The same principle applies to where the sidewalk will adjoin other concrete surfaces.
To get the best results, the surface of any sidewalk should never be glass-smooth. Sidewalks are for pedestrians, you wouldn’t want to make them slippery, especially in the rain. Ask your contractor about clever design solutions to this problem.
Cracked sidewalks are common. Superficial defects, such as fissures or chips can be repaired with masonry cements. Small holes can be patched with ease. Take into consideration that achieving a perfect finish is very difficult, because the materials are bound to have different colors and textures. To achieve the best result, contact your contractor and he will guide you through the process.
If the damage is more severe, often the best solution is to remove the damaged concrete and start anew. If that is the case, the challenge is to achieve regularity between the damaged part and the rest of the sidewalk. In these cases, to get the best result, it is better to call a professional.