[ex-Khobar Andy]

At the back of my garage there is concrete to about 3' above ground (the grade slopes) and then the brick veneer above that. I want to put in a raised bed for vegetables etc along the back using landscape timbers. So it would be about 20' long by 2' high x 3' depth out from the garage. First question and I haven't decided the esthetics of this: can I use the concrete foundation as the back or will this eventually damage the foundation? Second question: if I decide to make a back to this bed using the same landscape timbers, can I put it right along the line of the concrete foundation or should I leave a few inches of space so it can 'breathe'?

 

[Nealtw]

You can use the concrete for the back if it is below floor level of the garage but if it is above floor level you will need to water proof the concrete just like you were back filling. We built a few of these and always lined the wood with poly to keep the treatment out of the dirt.

 

[ex-Khobar Andy]

Yes it's below floor level - about a foot. Wood is treated with copper azole which is allegedly OK for vegetables. But I like the idea of some heavy duty plastic as a liner which will also make sure that soil will not leak out through inevitable gaps.



As I say, I might in the end go for timbers on four sides because I think it would look better.



BTW Neal - I've posted here maybe 6 or ten times in drywall, plumbing, electrical, carpentry and now masonry forums. I think you've given me advice in most if not all of these. So thanks for your help over the years at (I think) four different houses.

 

[Nealtw]

Yes it's below floor level - about a foot. Wood is treated with copper azole which is allegedly OK for vegetables. But I like the idea of some heavy duty plastic as a liner which will also make sure that soil will not leak out through inevitable gaps.



As I say, I might in the end go for timbers on four sides because I think it would look better.



BTW Neal - I've posted here maybe 6 or ten times in drywall, plumbing, electrical, carpentry and now masonry forums. I think you've given me advice in most if not all of these. So thanks for your help over the years at (I think) four different houses.

You are more than welcome,

Yes the newer treated lumber is with copper only or mostly but will not last in ground contact. I assume you will be using ground contact timbers which are still treated with CCA, the fun stuff. :surprise: