Not if the wall is under 4′ tall. In the city of Coquitlam and most other cities, retaining walls under 4′ tall do not require any permitting. Walls above 4′ in height will require a city permit and an engineer to design and inspect the wall construction. If you need to build a retaining wall above 4′ tall, we submit the documentation and get the City’s approval. The process is not complicated as we have a structural engineer we work with. 

We can construct retaining walls that can hold a higher elevation change without engineering and a permit by staging shorter walls at a 2:1 ratio. This staging of walls can sometimes enhance the appearance and function of a property.  

In the City of Coquitlam, Port Moody and surrounding areas there are a large percentage of homes bult on hills that have retaining walls. No two projects are alike. The size height and purpose of the retaining walls will differ which is why an on site visit is required for an onsite quotation.
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Other factors will depend on if the wall supports a positive surcharge, such as a structure above.
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If the wall is 4 feet or higher an engineered interlocking block or concrete wall is required. We can build pressure treated wood retaining walls under 4 feet. We can also build any style of retaining wall to any height.

We have a wide range of options for interlocking stone block systems and can show you all your options and make suggestions. We can also install basalt boulders or stack stone walls. In all options we can integrate a full landscape design into the walls.

If required, we install piping and integrate the system into the storm drain on the property or as the layout allows.

There is a large selection in block styles and colour options. We use Allen Block, Pisalite and Valley Stone. Within these brands, there are several sub brands and colours. 

We start with excavation of soils then installation of a base granite and grading. The wall base course is installed, drain pipe, granite backfill, filter fabric, soil backfill and compaction is done. For some walls, structural geotech is installed. 

In Coquitlam, Port Moody and Port Coquitlam, many homes have been constructed on hills and mountain sides, the location combined with large rain seasons create water run off sub grade. The sub grade water flow and accumulation builds hydrostatic pressure (wet soil like mud) behind retaining walls and can exert thousands of pounds of  pressure per square inch on the wall. The old lumber retaining walls typically have no way to release the pressure. Improperly installed retaining walls can fail within 1 year. Sometimes if a retaining wall has a failed drainage system or no drainage system, the wall can fail. It is critical to hire a qualified contractor that will build the wall and every element carefully. 

Retaining walls above 4′ tall can cause significant safety and liability risks, this is why the city requires these taller walls to have structural engineer oversee the construction process with inspections.

When engineering of a retaining wall is required, the engineer provides a blueprint drawing of the particular wall system we choose and stamps the drawing, signing off on the liability on the wall’s structure. The engineer will do site inspections to check the elements in the wall are being installed as per drawing; geogrid length, granite backfill, filter fabric, drain system, proctor density compaction of base and  backfill. 

Yes, a failed retaining wall can be a valid home insurance claim, depending on the particular circumstances. A failed retaining wall can be a large liability for the property owner, this can cause further water run off onto city or other properties. When a retaining wall fails on the parameter of the property, often the city has become aware very quickly and issues a notice to the property owner to rebuild the wall. 

It is common for both property owners to split the cost of repairing shared retaining walls and fences. In some cases, it may be practical to hire a surveyor to find out who’s property the retaining wall sits on. The cost of a surveyor is around $1000 for the Coquitlam area. 

If the wall supports a yard elevation and is above 2′ in height, a block wall with core filled granite should be used. The wall pricing will be similar for walls above 2′ in height as the scope of work to install wood walls and block walls are similar. Wood walls require “dead man” ties which excavation is required. Block walls also require excavation and a geo tech fabric installed for anchoring in most cases. When hiring a retaining wall contractor, it is critical to understand how the contractor proposes to build the wall and what materials will be used. 

The saying “you get what you pay for” applies directly to the contracting business. When quotes differ significantly, there is usually a different proposal of job task and or materials which has not been identified. It is sometimes important to supply a design or drawing for a contractor to base a price from. If you only have a concept, different contractors may have different ideas. Some contractors will skip steps and leave out critical materials simply to achieve a lower price. Never, will the same product, service and quality come at a significantly different price. It is important to be very careful in which contractor you hire to do work on your home. A reputable contractor should present a positive online and social media presence to show their ongoing work.