12 years minimum, preferably 15 years+. Full time, not part time. Minimum 70,000 feet per year. Ask for company photos, not franchise photos, installation, addresses, and referrals. All work should be completed by the company you sign with. Never accept subcontractor work.
Trench should be dug 1 1/2 inch depth by 10 inch wide. Great care must be taken to eliminate bumps and fill in low areas. Finished base should be uniform and consistent to produce a finished curb with a consistent height. You should be able to mow on curb without having to trim. This should be part of the guarantee.
Design is crucial and should compliment your existing or new landscaping. A professional design should flow elegantly and gracefully accenting existing and new planting areas. Ideas and expert consultation should be given, not just an estimate form filled out! Ask for photos of different designs and installations.
Straight Areas: Straight areas should be just that… STRAIGHT. No wavy lines. Even with a high quality curb machine, proper training and experience is needed to produce straight lines.
Curves and Contours: Design and creative ability is crucial. Be cautious of quick, wavy turns that are not contoured correctly, and a busy “snake-like” look. Only simple, precise contours should be done. Look at photos and see jobs.
Quality Product Specifications
Cement: Type 1A or 2A Portland cement should only be used. Must be air entrained if using straight Portland.
Sand: Fine washed sand is best.
Reinforcement: Polypropylene fibers are added at the ratio of 1.6 pounds per cubic yard and 1/8″ steel cable should be run through the entire curb during the extrusion process to minimize shifting and/or separation.
Mix: The mix should consist of 4 parts washed mason sand to 1 part cement. Fibers added during the mixing process. If color is desired, it is also added during the mixing process.
Control Joints: 2 to 2-1/2 feet apart. Joints should be scored half through the concrete. Straight bladed tool should be used. Width of joint shall not exceed 1/8 inch.
Strength: 3500 pounds per square inch.
Should be patented and made in the United States. Some companies use machines not patented in the U.S. and actually are imitations of the originals. A high powered gas machine is better for compassion and produces as stronger curb.
Curb should be extruded extremely close to lawn side of trench. There should be no large gaps between lawn and curb. Homeowner should not have to fill in dirt or put sod back in. Curb should match existing lawn elevation creating easy mowing and maintenance.
Integral, (base color) should be mixed thoroughly into the concrete. The base color should always be measured to produce consistent color batches. No colored sealants, paints or slurry coats should be used to just “cover up” the gray concrete. Only a well-known company, that documents all the steps in the manufacturing process to ensure the pigment will be the most consistent in quality and color, should be used. The base color should be complimentary in color to the surrounding aesthetics and be natural in appearance.
Stamping and Texturing
All companies should offer this. Experience and craftsmanship is the key in making this process look great. To produce a realistic, natural appearance, release, or accent colors should be cast on the curb and then rolled and stamped onto the curb. Choosing complimentary colors to accent landscaping, bricks, pavers, walls, and your home’s exterior is the key ingredient in producing a natural, marbled, antique look. Various rollers, textures, and stamps are used to produce just the right look for your application. A solvent-based sealant will be applied once the concrete has had time to cure properly.
All starts, stops and tie-ins must be professionally done. They should not stick up or look unsightly. All tie-ins must be clean, flared in, and aesthetically pleasing.
Excess concrete deposited along curb machine mold should be picked up so your lawn can grow to edge. All pieces of concrete dropped on lawn or other areas in the yard should be picked up. Driveways and sidewalks should be swept and hosed off as needed. A large tarp should be laid down when mixing to prevent any mess on the street. Yard should be left as they found it. Unsightly concrete waste makes your curb look inferior.
Plain and simple… a warranty is only as good as the company backing it up. Don’t be fooled by a company that offers an extended warranty without thoroughly explaining what they will cover. A 2-year materials and workmanship warranty should be standard. A reputable company should fix or replace anything under the warranty… no questions asked!