Planters from concrete blocks - design ideas

[Adam2]

Planning to make some planters (well design them!) for the front of our house about 650mm high with a planting area about 300 wide. 

 

What thickness blocks should we use for the planters? I was thinking bottom 2 courses could be regular 100mm thick blocks and top course could be 50mm thick to give a nicer look (level on outside but wider planting space in inside). We'll then render the outside of the blocks and line with thick plastic sheeting.

 

Are there any kind of blocks designed with sloping top edges that could provide an even narrower top edge say 20mm that slopes inwards? Have had a google but nothing yet

[Carrerahill]

Things to consider here are how are you going to finish the blocks, if you plan to render them you will need to consider the constant dampness that will come from the inside of the planter, through the block and damage the render, if you use facing brick it could be the same, so you need to consider how you will build them and put in an isolation layer for moisture.

 

Blocks are blocks, you do get facing blocks but you probably want to be looking at facing bricks.

 

For construction ideas consider some methods used in the waterproofing of retaining walls. A Geo-drain type membrane might help you here.

[Adam2]

1 hour ago, Carrerahill said:

if you plan to render them

Yes will be rendered. Inside was planning thick plastic sheeting +/- the same kind of membrane we used on our basement waterproofing to stop the water / dampness affecting the render.

 

I wanted specifically to know if there are any kind of blocks - or other ideas to get a sloped internal edge to the top course

[Adam2]

Gone with 50mm bricks to make up the top course as couldn't find anything else at short notice