How to build a planter box with seating?

[michy81]

Hi all

I'm working how to go about creating an outdoor planter box with seating. Got a few questions. I'll attach a pic of the space and what I hope to achieve. 

Plan is to build with narrow besser blocks and rebar with 2 separate footing leaving sand ground between, filling with rocks, landscaping mesh and then soil for planting. 

1. Will this be sufficient drainage?

2. How do I waterproof the exterior as I want to butt it up close to the garfen shed and fence?

3. What can I use to fill the gap between the fence and concrete so it doesnt fill up with leaves, nuts etc and create moisture against the wall?

 

 

First question 

[Dave-1]

Good Evening @michy81 

Wooooo Now that opens up options for sure!

If you are considering that I would really suggest to sit down with a sketch pad and start scrolling through pages like this and cruise through some pages just to get ideas. The forms you could make, especially with reo inside might change what you have planned. 

For instance I saw some bench seats at work that were made from poured concrete with styrofoam in the large foot at one end (to save concrete and keep the seat lighter I presume) and slatted timber boards on top. It looks stylish and functional. 

Ive only ever done some concrete repair and concrete footings for lamp posts but for sure the other members will have some brilliant ideas

Mind is running off with ideas! Just rem if you are going to have a garden bed make sure water can exit

Dave

[EricL]

Hello @michy81 

In regards to the overall construction of your planter box, I would encourage you to build it as free standing with four walls to keep the soil inside the planter and not touching your fence. I recommend sealing the inside of the planter, this will prevent hydrostatic pressure from occurring on the outside of the planter. This will allow you to paint the outside of the planter with whatever colour you want, and it won't peel off.

Building it out of poured concrete pretty much allows you to almost create it in whatever shape you want. But as @Dave-1 said make sure you provide a drain point for the water.

If you need further assistance, please let us know.

Eric

[michy81]

Hey Dave I'm not really understanding the Styrofoam bit. But loving your enthusiasm. One of our good mates forms up skate parks so I'm sure he can form up 2 walls for me. Can you find the Styrofoam post and tag me. I can't see the point of the Styrofoam if you put timber on it. My thoughts were to form up 2 walls with rebar slotting out to bore the timber slats to. I think if we do this I'll just to ve sure chuck a couple of poly pipe angled dains in to capture any run off to under the paver/rock area. Is soft sand as we're near the beach and never had an issue with drainage but prepared to chuck some in as contingency 

[michy81]

Thanks for the feedback Eric. I'm  still in the thinking it out stage. I've sketched up dimensions. I've taken everyone's advice and will have it 10-15cm off the fence and shed. Are you certain there's a benefit from water proofing? I'm planning on only putting Mondo Grass on the top. So, rock fill between walls, landscaping mesh, soil then Mondo. Any further thoughts with this knowledge?

[Dave-1]

Good Evening @michy81 

Will try and remember to take a pic of the benches at work tomorrow so I can explain easier

Dave

[EricL]

Hi @michy81 

When soil and water area placed in a container, the soil absorbs the water and usually flows down in all directions. The trapped moisture in the soil now needs to evaporate or get out somehow and it will find every exit available. This includes the porous surface of the poured concrete. When water passes through the wall of the concrete any paint product you have on top of the planter will literally get pushed off. But by sealing the inside walls of your planter moisture can only evaporate through the top and your paint is preserved.  

If you need further assistance, please let us know.

Eric