How deep do I need to bury the first row of Flex MSE bags?

Typically, 12″ (300mm) of excavation to accommodate one layer of Flex MSE Bags on top of 6” (140mm) of gravel is required subgrade to lock the toe of the wall into place.  

One of our tallest GeoBag walls in Western Canada, 39ft (12m), has only a single row of Bags buried at the bottom of the wall.

Engineered walls can specify additional layers of Bags subgrade depending on soils, hydrology, and surcharge. Walls built in waterways should consider the effects of scour on the ends and bottom.

Do I need an Engineer to build a Flex MSE wall?

Areas have different guidelines depending on local soil conditions and topography. Typically, 3’ – 5’ (1 – 1.5m) high of exposed facing is the limit for any system before having to get an Engineer to design a wall or slope.

Always check with your local municipality’s Building Permit Department prior to building.

What type of reinforcement do you use when building a Flex MSE wall?

Any Flex MSE structure over 2’ (.6m) high should integrate a reinforcement system. Typically reinforcement such as geogrid, earth anchor or rock anchoring is used. For walls under 4’ (1.2m), Flex MSE Units can be installed using our Tie Back Method.

Where Geogrid is required, we typically see it specified at lengths embedded into the backfill to 80% of the wall height (1m minimum lengths)  and spaced every three to four layers of Bags (18-24″).

Reinforcement lengths and elevations may need to change depending on soils, surcharge, or other site conditions.  Design assistance from a qualified Engineer will be required on all structures taller than municipal limits, and is recommended for all sites in/around water.

Trexiana provides standard CAD drawings for a host of applications, as well as Specifications and Best Practices.  We also have a full Installation Guide available, please contact us for more information.

Before undertaking any retaining wall or slope stabilization, please contact your local permitting bodies for building guidelines.

What range of angles (slope/batter) you can create with Flex MSE?

Flex MSE can be installed from Horizontal (creek channel cladding, outfalls, etc.) to Vertical (as a living wall attached to existing structures). For MSE style walls you can go up to 85° with the same two components.

The typical range for Flex MSE is between 35° and 85°. Angles less than 35° can incorporate a tiled ‘mattress’ layout, as opposed to the typical stacked ‘running bond’ layout.

Thanks to the interlocking soft-armour capabilities, it’s simple to integrate different angles into the same structure. Beautiful, curved designs are a breeze with Flex MSE.

How do I vegetate my Flex MSE installation?

There are several ways to plant a Flex MSE installation.  You can choose simple and low maintenance options, or more intricate custom aesthetics.

Grasses grow beautifully in Flex MSE. Hydraulic seeding (‘hydroseeding) of the facing is very common.

Flex MSE is the only choice for live planting. Live planting with native groundcover plugs directly into the Bag, or laying more mature plants between Bags as you build also gives great results.

Often, a combination of methods are used to create the desired effect. See the Vegetation section for more details.

Do I need special training to install Flex MSE?

Flex MSE is very simple to install.  Smaller DIY projects are an easy weekend project for homeowners with little or no experience.

Contractors installing Flex MSE for the first time will find many similarities to other segmental systems, and many distinct advantages.  The great news is, Flex MSE is the only Vegetated Wall System that actually Certifies its installers. If you’re interested in becoming certified click here for our application form.

Please see our Resources section for details, and contact us for specific technical questions and Team Certification.