Why do sidewalks have expansion joints

So, spacing of control joints is critical. The number of expansion joints necessary in a driveway depends on its length. Size and thickness of your expansion joints depend upon the thickness of your driveway or sidewalk concrete. Materials used for expansion joints must be tolerable to extreme weather and temperature conditions. Expansion joints in the driveways of older homes are often filled with weeds as the result of a wooden driveway expansion joint used by building contractors in years past.

When the wood rots, all that remains is a crack as wide as the board that originally filled it. The space quickly fills with dirt, rocks and weeds and becomes an eyesore. Call Cracking occurs because concrete naturally expands and contracts with temperature and moisture changes. Experienced concrete installers like those at Custom Concrete Contracting use control joints to prevent random and unplanned cracks.

What these joints do, essentially, is ensure that most cracks will occur at the location of the joint and not elsewhere in the concrete slab. Contraction joints are cut or tooled into the concrete surface and actually serve to weaken the concrete along that line, so that when the concrete contracts, it will separate slightly at that spot. These joint are placed where a slab meets a building, where a slab meets another slab, and where a pool deck meets the coping.

A pliable material is used asphalt coated, cork, plastic to construct these types of joints. The material should extend the depth of the slab and extend the full width of the slab.

Ideally, for expansion joints on the exterior of a structure, sealing these joint is preferable. Using a high-quality urethane caulk Vulkem will help prevent precipitation from entering the joint and freezing. With a little planning prior to pouring, utilizing control joints and expansion joints will help minimize cracking and extend the life of the concrete. If your existing concrete driveway, sidewalk, or patio happens to crack over time, there are several things you can do to prolong the life of the pour.

There are adhesive caulks available that can be applied to seal the cracks to prevent water from getting in and freezing. These caulks are available in different colors.