What type of liner do I need for a raised garden bed?

Before You Begin

There are a few considerations to take into account before diving into construction—and they are important ones.

Load on the Roof

The first step is to evaluate your roof’s loading capacity. This is the amount of weight your roof structure can support and includes everything: planter boxes, soil (when wet), possible water storage, weight of crops at maturity, equipment and such temporary loads as people and snow. This may be your biggest expense and will determine whether you are willing to pursue an edible roof or not. Working with a structural engineer is a must!

Contact a structural engineer and discuss what you intend to design; for this, a plan of your garden is required. The engineer will evaluate the possibility of carrying out the project, what it would take in terms of reinforcement, and the influence of obstacles (vents, chimneys, etc.) and/or possibility of eliminating or moving them.

Municipal Regulations

Review your municipality’s regulations. Architects or building designers can often assist you in interpreting building-code requirements for green roofs.

Prepare Your Roof Structurally

Ensure it meets municipal building and safety requirements for a green roof. Also, check that your roof membrane can support walking and planters—you don’t want to risk a leak! Flat roofs are best.

Build Planters to Hold Soil

Gravel on the roof encourages drainage, which is an absolute must, so check that your roof drains properly!

Line Your Planters

Use weed block to contain soil while allowing drainage.

Add Green-roof Soil

Lightweight soil specific for green roofs is placed in raised planters (soil weight: 75 lb. per sq. ft. or approx. 300 kg per sq. m). A bonus is that this mix starts out with no weed seeds.

Weed mat is a good liner for your raised beds. Good luck!

Hi Barbara, Liz here from SimpleDecoratingTips.com. Last week I shared this raised bed barrel planter idea my parents made: http://www.hometalk.com/diy/upcycle/ingenious-tips-to-diy-this-vegetable-planter-28035221