Replacing An Existing Retaining Wall

Replacing an Existing Retaining Wall

As retaining wall contractors who have been serving the Pittsburgh area for many years, we have encountered nearly every situation that could come up. Because our region is so hilly, retaining walls are common across all types of residential and commercial properties (so we stay pretty busy)!

Many times with new residential and commercial development comes the need to build new retaining walls to support the project.  However, there is just as much need to repair or replace existing walls that have deteriorated over time.  Old walls that are falling apart could become a safety hazard and should be replaced as soon as possible.

Without a doubt, the combo-question I get asked most is…

How much does a retaining wall cost and what kind of retaining wall can I install?

Customers and potential customers alike are almost always amazed at the cost of landscape work in general and retaining walls in particular. Cost is not just about the materials used for the project; it is also a function of the time involved in the design and installation. Labor is the key component of any construction project and any contractor building a retaining wall has a large labor cost.

But it isn’t just limited to retaining walls. Labor costs are a big part of pretty much any service you have someone perform. Have you ever checked the invoice whenever you have work done to your car? Take a look next time; the cost for the parts is usually a fraction of the labor cost.

The second most asked question is one that continues to evolve.

Not too long ago, when a customer wanted a retaining wall installed at their residence, the choice was simple; get stone or railroad ties. That is certainly not the case today. With new materials come many new options. And which wall type to go with requires some thought.

Before starting your project, consider these tips when thinking of installing a retaining wall in the Pittsburgh area:

1. Materials: When choosing materials, select the type that is best suited for the desired result. Many long-lasting materials are available for landscape use including Versa Lok, Keystone, flagstone wall rock, Xeriscape rockery, railroad tie maze, regal stone, Pyzique stone, Windsor stone, and framed fence. Also consider recycled concrete paving-treated timbers, vertical poles, pre-cast concrete modular units, poured concrete, and brick veneer.  Not all materials work equally well in every situation, so design will dictate what material(s) could be used.

 2. Type of wall: The type of wall you choose should be determined by need. Decide if you need a poured-in-place concrete “structural” wall or a much less expensive “dry-laid wall” consisting of stacked, open-joint material.

 3. Determine design or on-site placement: Planning ahead will help you avoid the expense and time it takes to relocate a wall or to modify retained areas once they’re installed.

4. Drainage: Most retaining walls fail because of pressure against the wall caused by water or soil-moisture build up behind the wall. All walls should provide for the back-of-wall water to freely drain down and away from the wall. This is accomplished with gravel backfill, or manufactured drainage blankets and drain pipes. Structural walls require “weep” holes to allow water to drain from behind the wall.

5. Foundations: A wall is only as good as its foundation, and all retaining walls should be built on structurally sound, compacted foundation sub-base material. Leveled and compacted earth or gravel fill are acceptable. The foundation material should extend at least one foot beyond the front and back of the base width of the wall. When building dry-laid stone walls, place the largest, most stable stones on the bottom of the wall, and be aware that the base width may need to be as wide as the wall is high.

6. Cant or batter: Walls are more stable and structurally secure if they slope back or “lay back” into the retained slope. This amount of variance from true vertical is called “cant” or “batter”.

 7. Anchors: Timber walls and other walls of solid horizontal materials usually have “T” anchors extending back into the slope into undisturbed earth. This helps walls resist pressures that force them forward, or cause them to pivot on footing material. A good rule of thumb is to provide at least one anchor per 16 square feet of exposed wall face.

Installed wall costs generally range from $20 to $35 per square foot of wall face for dry-laid materials. Cost will vary considerably depending upon materials used and overall wall height.

Structural wall costs may range from 2-10x that of dry-laid walls.

 Before you get started on a retaining wall project, be sure to take the above into consideration.  This will help you plan accordingly and will probably lessen the sticker shock from the project bids.

All of this may seem overwhelming (and it can be), that is why we recommend hiring an experienced and professional retaining wall contractor. When you are ready to plan your project, give us a call at 412-203-4698 so we can give you a free estimate!

Schedule a Free Estimate Today!

Call 412-203-4698

or

3 Keys To A Successful Retaining Wall Project

The Pittsburgh area has retaining walls all over the place. At a glance, a typical wall might look like a simple block of stones or timber. But in reality, there is a lot of work that a retaining wall contractor has to do to ensure that these systems are properly installed. Only a well-engineered wall can wage its ongoing battle with the forces of nature that we combat here in southwestern PA.

“Cheap” contractors generally cut corners either on purpose to increase their profits or do not have the expertise required, so their labor cost is lower. You get the job done at a lower price, but at what cost?

Here are 3 keys to make sure you have a successfully completed wall project.

1. Have it built right

All steps of building a retaining wall need to be followed to the letter. Hiring a contractor based on price is asking for trouble.

Well-built retaining walls begin with landscape fabric, backfill, gravel and a drainpipe. If, for example, the backfill is added at the end the wall might not compact thoroughly. It is therefore important that all principles are followed from the start to the end of the project to ensure long-term success. In most cases DIYs are unable to follow the correct guidelines only to end up constructing “half-baked” walls that eventually collapse. That introduces danger to residential and commercial properties.

 

2. Tiny details matter a lot

All retaining walls should lean into the hill at a particular angle and height. Timber walls for instance should always be tied to the hillside using strong anchors. Other types of walls may require web-like tiebacks or geo-grids. Only a pro will be in a position to adhere to all these guidelines at every step of the way. Remember, retaining walls have to wage the battle of massive forces of nature and therefore need to be properly fitted and fastened to stand the test of time.

 

3. Getting the right wall for your situation is critical

Timber walls are relatively easier and cheaper to install. Their main downside is that they are not as long-lived as concrete ones. Also, timber components are a bit difficult to manage.

Inter-locking concrete block systems have has the benefit of being extremely strong and durable. On the downside, they require metal pins to bind everything  together and can be a challenge to line-up evenly.

Poured concrete walls are generally the strongest and most durable type of wall that can be built. However, concrete walls cost more per square face foot installed than the others.

This cannot be overstated…it is important that all rules for wall construction are followed very closely. The number of blocks, tiebacks and pins needs to be calculated correctly and there is no room for cutting back to save some money. In addition, when stacking blocks, small pebbles and irregular layers need to be taken into account.

 

All of this may seem overwhelming (and it can be), that is why we recommend hiring an experienced and professional retaining wall contractor. When you are ready to plan your project, give us a call at 412-203-4698 so we can give you a free estimate!

Schedule a Free Estimate Today!

Call 412-203-4698

or

Retaining Wall Services

Design-Build
New Construction
Repair
Concrete Block
Natural Stone
Wood/Timber

 

Contact Us

The Wall Experts of Pittsburgh

412-203-4698