John wrote:
A friend has asked me to install a security post at the end of his
driveway, the sort that lay down flat and lock. The problem is his
drve is block paving right up to the tarmac footpath apart from a
drainage channel. I have explained to him that the pavers are only a
few inches thick and that the post will act as a very good lever if
somebody wanted to remove it (and the pavers it will be bolted to)!! He
says it is only really as a visual deterrent. My question is are
pavers hard to drill and will they split under the pressure from a
rawlbolt. The post has come with a tube of No Nonsense Injection
Resin and four 12mm x 100mm self cutting bolts. I presume the resin
will be a waste of time in this application and that the bolts are
too long, would this type of bolt (but shorter) be better than a
Rawlbolt. How thick are pavers 2 1/2" or so?

The pavers are either 50mm or 60mm and neither are any use at all for
bolting things to - your friend may think it will be OK and act as a visual
deterrent but it won't - it won't last 5 minutes, the first time someone
brushes against it, it will be gone, given that the pavers are really just
bricks sat on a bed of sand.

To install it properly, you'll need to take up a few pavers and concrete a
patch about a foot deep and six inches square, the easiest way to do this is
to cut out the shape of the hole with a grinder, so that the BP pattern
isn't ruined, and concrete the hole to the top of the pavers, leave for a
week or so, then use the resin and bolts as normal.

for added strength, prior to casting the concrete, knock a few pieces of
steel into the sides of the hole and leave protruding into the void to be
filled.


--
Phil L
RSRL Tipster Of The Year 2008