Which Concrete blocks in the garden

[Kevlar]

Hi

I am building a Rill (6m x 50cm x 50cm) in my garden. Found some instructions which I am following; these call for using concrete blocks to line the channel in which the rill will be constructed.

The blocks are to line the channel; a butyl pond liner will go over the blocks.

Question: Which type of blocks to use, aerated, medium or high density blocks? From what I have researched, aerated might not be a good idea, since water penetration and frost will damage the construction over time. Cost wise aerated are a bit more expensive, but they all seem to be around the 90p per block mark. I reckon I'll need about 30 blocks.

Also there seems to be some discussion as to the make of blocks to go for. Seems most favour B&Q medium density over Wickes. Any opinions?

Cheers

K

 

[Deluks]

Doesn't matter which concrete one you use, theyre all much of a muchness. What's a rill?

(the lighter ones would prob be ok but the concs are cheaper)

 

[Kevlar]

Thanks for the post.

A Rill is basically a rectangular pond, or shallow channel of water.

Cheers

K