Seeking advice - Looking for general advice

[rufus]

Hi all,

I am attempting to lay some paving in my backgarden about 16m square. I have put crushed limestone down, and was wondering if it is absolutely neccessary to use a "whacker", before putting the sand down.

Also I have a concrete path going around my backgarden, which is looking rather bleak with moss and dirt. Any ideas on how I could improve the path.

I was thinking about paving over it, however I am worried that the paving would raise the ground level too close to the damp proof coarsing . Could I somehow put a new thin layer of concrete or even fine cement over it? Any ideas?

[steve r]

You should use a plate compactor on the limestone, this will ensure that no voids are left.
No point in spending time and money on your paving only to see it subside. See this page http://www.pavingexpert.com/faq_subbase.htm

How about using a pressure washer on the concrete path,
it's surprising how much crud can be removed with a few hours work?

[Paverman Dan]

I heard vinegar works on moss, never tried it.

When it comes to compacting the sub-base (in the Colonies we call it base) the answer is always YES, in 4-6" lifts using a 7000# vibratory plate compactpor, to the point you should not be able to drive a spike into the sub-base with a maul with ease, and with imperfections at no greater than 3/8" over 10' (there's more stringent tests, but it sounds like this would work for now).

Maybe someone can convert that to Metrics for this fellow.

[simeonronacrete]

How about cleaning the path then laying Ronadeck Fast Grip on top; it's only ~ 3mm thick, sticks to sound concrete and gives you the look of natural aggregate - because it is!.

See Ronadeck Fast Grip.

Good Luck.

[Tony McC]

Dan - in Britain, Ireland and the rest of Europe, base course is completely different to sub-base . A base course is typically a bound, firm layer, whereas a sub-base is unbound material. In terms of typical materials, a sub-base would be crushed rock of some type while a base might be bitmac (asphalt) or a lean mix concrete (cement-bound). There are some bound sub-bases, but their use is limited to heavy duty constructions, way beyond what we'd normally expect for a driveway.

Tolerance for a standard sub-base would be ±10mm over 3m, which is as near as dammit to your 3/8" over 10 feet. Compaction is acheived by a minimum number of passes by approved equipment. On critical projects, a nuclear density gauge might be used, but for most driveways, 8 passes of a decent plate compactor will do the job.

Going back to the original question, simple household bleach is a great way of dealing with moss on concrete.