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Concrete pavers are popular because they eliminate the problem of
unsightly cracks common in a poured concrete driveway. Fact is
however that if they are installed wrong you will be wishing you only had
to deal with those unsightly cracks!
Seems today, every Tom, Dick &
Harry is an expert at installing
concrete paver's and there is a wide
gap in price. Here are some
questions to ask to separate out
who you don't want to deal with.
What goes under the pavers?
The sandy soils of Florida will only support about 1,500 pounds per square foot. The weight and surface
area of vehicle tires will far exceed that. Pavers will sink (and concrete will crack) unless there is something
added to disburse this weight. In our market area, that something is "ground up concrete" commonly called
"base". A truck load of base will cost the contractor about $500 and doesn't go far. First, the sub-soil MUST
be fully compacted. Plate compactors that look similar to a lawn mower work fine but only if combined with
water. For a residential driveway, the minimum thickness of base should be 8", compacted every 2". The
base should also be wider than the driveway by 6" on each side. If you want to make sure that a 18,000 lb
moving truck won't sink in, use 8" of base material.
Why reinforce the edges?
Why a good layer of base will support a vertical load, small pavers at the edge tend to slide off with any
side loads. To prevent this, contractors use a bed of mortar to keep the pavers in place. The problem here
is that the mortar itself has little strength. To be of any value the mortar should be a triangle at least 3" by
3" with a continuous #3 rebar in the center. Mortar takes time to mix and rebar is a pain to bend into place.
You can tell a poor installation real quick by inspecting the edge reinforcement.
What keeps grass from growing between the paver's?
Just about nothing. On TV shows describing how to install pavers, they always add weed filter fabric
before stacking the pavers in place. This is cute move but at best it adds 50 cents a foot to the project
cost and only lasts 6 months. The best way to keep grass and weeds from growing between the pavers
is with a tight installation and sealing the pavers once a year.
Why is my concrete driveway cracked?
Hairline cracks in concrete are almost impossible to prevent. Anything larger than a hairline is
caused by one or more of the following: a poor concrete mix; improper compaction of the sub-soil;
no base, little base or improper base under the concrete; not enough or the wrong placement of
expansion joints; and, the most common, improper curing, especially in hot weather.
When should I seal my pavers?
A paver is a colored cement block. A by-product of the curing of cement is calcium
carbonate which is a white film that collects on the surface of the paver. Most of the
calcium carbonate comes to the surface over the first year. It can be removed with
chemicals and pressure washing. If you seal the paver before the calcium carbonate is
removed, it is next to impossible to remove.
If I have a cracked concrete driveway,
are pavers the only alternative?
One option is to tile the driveway with "floor brick" (see www.summitvile.com). Dealing with
the existing cracks is not the problem. The problem is that the minimum brick thickness that
will work is 1" and with setting materials, figure 1 3/8" added to the driveway elevation. This
usually means re-doing the concrete portions at the entrance to your garage and at the street.
Still the overall costs are competitive with digging out the concrete and replacing it with
concrete pavers and the results are more appealing.
|Call us for free estimates to make your
driveway more appealing.
The least costly option is to patch the existing cracks, completely clean the
concrete and apply a concrete stain.
Look closely at this photo, you'll see where 10" of soil
have been removed to accommodate a thick layer of
base. If your driveway did not look like this getting
built, keep any heavy trucks on the street.