Our Installation Standards

Here is some really good technical information from Unilock, which is also a technical guide when looking for a good landscape contractor. These installation standards is what our company follows and what should be followed by any good landscape contractor.

Paving Stone Installation – the visual signs of quality workmanship

When you contact the contractor’s references you should make an attempt to see the contractor’s work. This is the best indicator of what the contractor’s work is like. If the job is three or more years old, you can also see how the job is holding up.

Design

Does the design have flair and does it give you a sense of flow and organization? Are the colors complementary to the house? Did the contractor employ borders and accents with a combination of unique textures, styles and patterns? Is it a pleasing combination? Was the project nicely finished off with trees and plants?

Grading

Is the paver surface properly graded to divert water away from any buildings? In difficult drainage situations, has a drain been installed to handle rain water? Do any of the patio grades exceed a 2% slope (2” drop over a distance of 100”)? If so, why? Anything over a 2% slope will make any patio furniture seem like it is leaning. On the other hand, anything less than 1.5% will not give you adequate drainage.

Base

Unless the job is several years old, you will never really know how well the base was prepared. With a poor base installation, problems generally arise in the first two years. If there is any sign of rutting, ponding or settling near the edges, it indicates one of four things. 1. Incorrect base material and water absorption (one of the reasons that copious amounts of screenings should not be used as a bedding course). 2. Insufficient base for the application. If you do not have enough base for a driveway, it will not support the load that will repeatedly travel over it. 3. Poor compaction by the contractor, which is usually caused by using equipment too light for the job. 4. Absence of any edge restraint. If there is no edge restraint then the edge pavers can move laterally into adjacent gardens or grass, creating unsightly gaps between the pavers at the edge.

In any case, if there is rutting it’s usually a result of the contractor’s poor installation methods. There are sometimes extenuating circumstances with respect to the failure of a job and this usually relates back to existing site soil conditions that the contractor was not made aware of or that were beyond his control. Below is a chart showing what is recommended for a base for your project. A knowledgeable contractor may recognize a site’s potential base problem and recommend an alternative base thickness.

Cutting

Where pavers have been cut, look for the quality of the cutting. Are cuts clean and straight and do they align with adjacent cuts? Gaps greater than ¼” are generally unacceptable unless the project or product is designed to create a larger joint for aesthetic purposes.

Landscaping and Finishing

How well was the final project finished off? Is it neat and tidy? Are the planting areas graded in such a way that there will be no wash-out onto the paving stone surface? Even if there was no landscaping involved, examine how well the sod was restored around the edges and if it is properly graded away from the paving stone surface.

Retaining Wall Installation – the visual signs of quality workmanship

Design

Is the design pleasing and does it fit the architecture of the home? Is the design a practical use of space and will it function as it was intended? Did the contractor employ borders and accents with a combination of unique textures, styles and patterns? This is important so that the job takes on uniqueness and a creative signature all its own. On a structural note, walls over 31/2’ should be engineered by a registered engineer (consult local building codes).

Quality of workmanship can sometimes be a little more difficult to ascertain because of the varying projects that are constructed with modular retaining wall products. Most retaining wall products can be adapted to create not only walls but also steps, planters, pillars, seatwalls, outdoor grills, fences, mailboxes, fireplaces and fire-pits. Each item has its own installation specifications and requirements. But once again, the base is critical for each of these elements, as is the drainage below or behind the wall.

Grading

Much like bricks and mortar on a building, retaining walls and related elements such as planters, steps and pillars should always be constructed level, or in the case of pillars, plumb. Walls should not be constructed on an angle. It is unattractive, impractical and structurally unsound, especially if there are curves or corners, which can be problematic if the wall is not installed level. When dealing with slopes, the top of the wall as well as the base of the wall should be stepped to accommodate the grade.

If steps were constructed using wall units and coping units, take a test walk up and down the steps to see if they feel safe and comfortable. Retaining walls are usually constructed to level off an area or to change the grade in order to accommodate part of the landscape, such as a patio. It is imperative that the area behind the wall be well drained with a proper drainage layer of gravel so that frost will not push the wall over.

Landscaping and Finishing

As with a paving stone installation, ask yourself how well the final wall project was finished off. Is it neat and tidy? Are the planting areas graded in such a way that there will be no wash-out over or from behind the wall? Even if there was no landscaping involved, examine how well the sod was restored at the top of the wall and if it is properly graded away from the edge of the wall.

Information on this page was taken from the Unilock web site, most of which was copied but also in some parts modified in order to work with this web site. Hope it helps!