I got your email, Louise - Sorry, I've been away at a bonsai show & visiting friends/family. This is a tough one. As I understand it, you have a concrete block planter constructed atop a concrete slab, with no way for the water to make its way into the sand below the slab. Drilling holes in the block walls won't improve drainage. The only 2 ways to effectively improve drainage would be to make sure there is a 'bridge' between the soil in the planter and the sand below the concrete so the water can percolate through the soil, or to make sure the soil you use is porous enough that it holds little or no perched water. This would mean that your soil particles would have to be large & stable, insofar as their structure is concerned. Even the soil you see me holding above would be inappropriate for your application because that soil depends on the wicking action of the earth (in RBs) to ensure it doesn't remain saturated after rain/watering. It looks great, but if you have high standards it would be a disaster in a container or in your app. I'm thinking that about an 80% fraction of a mix of all purpose sand and all purpose gravel and 10% each of pine bark fines and Michigan (reed/sedge) peat or good compost would probably be the direction I would head. In subsequent years, I think all you'll need to do is mulch with pine bark to keep the soil healthy. If expense isn't a major consideration, you could use Turface MVP as the base ingredient for your soil. Topsoil and fine sand just isn't going to drain w/o help. The alternative would be to remove the old soil and cut a hole in the slab so water can drain from the soil in the planter, but it would have to be a hole of considerable size - preferably at the lowest point on the planter's bottom. If you have pictures, it's possible that something else might be devised that will allow the water to move out of the soil via some sort of passive wicking mechanism that we/you could devise, but I'd have to see the application in order to envision the possibilities. There might be a way to employ a false bottom by placing FRP panel on top of cement blocks that are resting on the bottom & building it like a self-watering container in reverse - where you employ a wicking column of soil to REMOVE water instead of supplying it, but I don't know how far you want to chase the issue? ;-) AL

dian, we've done the tape the plastic to the floor thing and didn't find any moisture. Dh & I even talked about painting the slab for a short term cheap solution, but agree that it would look pretty awful. We went to Home Depot & found some vinyl flooring strips called Traffic Master and were on the verge of ordering it when we thought we'd better come home & do some remeasuring first. I got online & found about as many happy people as unhappy, and really, about half the unhappy folks sounded like they hadn't put it down according to directions. Still, even though it would be a short term solution for us, I don't want to look at curling edges for 6-8 months either so we've backed off that for now. Thought we'd visit a Floor & Decor tomorrow & see what other options we have. If the TrafficMaster worked, it would be ideal. It would only cost about $600, and would be able to clean it during construction, and if for some reason we actually loved it, we could patch it in to the new addition & just leave it here.

I am about 150 miles south and just pulled out all tile and carpet replacing with new tile throughout except 4 bedrooms. i entertained the idea of polished concrete... love the look. But decided on tile and glad I did. Once everything was pulled up, found surprises. Cracks, funky chipped away part in three spots, and at some point some portion had linoleum or something (black glue gunk all over). Plus, if house is built right you should have expansion openings (the are called something fancier). If/when you tear out tile, be sure you have a budget to replace if needed.

How old is the slab? How flat is the slab? What's sitting on it right now? Let's start with the basics. Old slabs (built before 1990's) can have moisture issues. Without the right adhesives (and you would be surprised at how many adhesives that say they are 'unlimited' have rather sad limitations for moisture) you can get massive failures very very quickly. I'm always surprised at the 'glue down' the plywood and then nail down the hardwood. Why not just glue down the hardwood? It requires the same adhesive...so why not go ahead and do the hardwood that way...and skip the plywood. A floating hardwood floor (with proper moisture barrier underneath) is the one least likely to fail (due to moisture). A properly prepared slab (all the grinding/filling/leveling) is going to produce a lovely floating hardwood. And if you want a 'solid' feel underneath, go ahead and use a lovely 1/4" cork underlayment underneath the hardwood (but over top the moisture barrier). It is a really nice combination.