Archive for the ‘DIY’ Category

How to Repair a Paver Patio that has “Dips” and/or “Bulges”

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If your paver patio was not properly installed and/or it has shifted underneath, it may have developed “dips” and/or “bulges” that are unsightly and drain poorly.

No need for despair!  Unlike concrete and asphalt surfaces, paver patios can be easily repaired with a few tools, some additional materials and little bit of your labor.  Of course, if your patio is still under warranty, just pick up your phone and ask your contractor to come fix it!  To keep this as short as possible, we’ll focus on minor repairs you can do yourself.

And if our considering a new paver patio, don’t let this repair article discourage you.  Most of these kind of problems arrise from poor workmanship and contractors that don’t stand behind their work.  Paver patios are excellent solutions for areas with freeze/thaw cycles like in Cincinnati and will provide years of enjoyment if done right!  And that’s the only kind of patios Distinctive Patios installs.  Now, on with the repairs.

  • How big is the problem?  Is this a small isolated problem or is the entire patio a mess.  With the former, you can use a string line or level to mark the problem area with chalk since it will be harder to locate the problem area after your start the repairs.  For the later, you may need to remove all the pavers to do the repair.  This is a much more involved project and you might want to get some help.
  • Why did it fail?  Before you start fixing your patio, it’s best to try to determine the cause.  Regardless of the size of the problem, you can do some simple investigation to size things up.
    • First, remove one or more pavers to expose the problem(s).  If you’re lucky and it’s near the edge, start there.  If not, you can use a screwdriver to scrape away the joint sand and a small rubber mallet to break it loose.  Then use two screw drivers to wiggle and pry the first paver up.  For stubborn pavers that may have polymeric joint sand, you may have to use a power angle grinder to remove the sand or in the worst case, cut the paver in half.  Just make sure you have a spare paver.
    • Next, remove some of the leveling base sand to see what’s going on underneath.  A properly installed patio should be built on a firm soil base, should have ~6″ of compacted gravel base material and ~1″ of leveling sand under the pavers.
      • Ground Shifted Below – Backfill settling is a common cause of patio failure.  While this can continue for a long time, most settling occurs during the first four years.  Small areas can be repaired by adding more base gravel and re-compacting.  For patios constructed over new construction or around pools, we generally recommend a concrete base to bridge any possible voids that might develop.  But, if that approach wasn’t used, you’ll need to deal with this now.  Don’t rule out adding some concrete if the problem is likely to continue.
      • Shifting of Base Sand  – Over the years, the leveling sand under the pavers may have shifted.  In this case you can just re-level the sand adding more as necessary.
      • Root Growth – This can be situational.  If you think the roots are mature and they are below the top of the desired leveling sand, you can just re-level the sand, removing any extra gravel or sand.  If the roots are still growing or they are too high, they will have to be removed.  Trees and bushes normally can do without a few roots, but there is always a risk that you could do some real damage.  You’ll have to deal with the tradeoffs.
      • Eroded Gravel Base – If there is no obvious cause such as water, roots, etc., you can just add some base gravel and compact as described above.
      • Eroded Joint Sand – In some cases, the erosion of the joint sand can allow too much water to penetrate the surface and cause problems with the base.  We will talk about remedies to avoid this in the future later in this post.
      • Other Problems – If you believe that there is a systemic problem with the way the patio was constructed or you just don’t know, it’s time to get some professional help.  Otherwise, just use your best judgement to restore the gravel base and leveling sand.
  • Restoring the Paver Patio?  After having explored the cause of the problem, it’s time to put things back together.
    • Re-level and compact the gravel base with a sledge, hand compactor or a vibrating plate compactor depending on the size of the area.  Remember, if this is not done sufficiently, the patio is likely to fail again.  A well compacted base should bounce like concrete.  Don’t worry too much about the exact level of the base,  we’ll take care of that in the next step.
    • Now it’s time to re-level the sand.  Small areas can be done with a trowel to smooth it out, adding or removing sand as necessary.  For larger areas, you can use several lengths of 1″ pipe as guides to screed the sand so it is level.  Then remove the pipes and fill the voids with a little sand.  In either case, you should have the sand level ~1/4 to 3/8″ higher than the bottom of the pavers you are trying to match.  The reason that this is important is that when you install and compact the pavers, the sand will compact, removing air and pushing some of the sand up into the paver joints.
    • Next, replace the pavers following the original pattern of the patio.  Make sure you maintain the joint lines for larger areas.
    • Once the pavers are in place, spread joint sand with a stiff broom.  Choice of the joint sand will be important as you want the repaired area to look like the undisturbed areas (see note below on joint sand).   You will need to set the pavers with a dead blow sledge, hand compactor or a vibrating plate compactor depending on the size of the are.  Be careful with non-tumbled concrete or brick pavers as you could scratch or break pavers with the plate compactor.  Repeat the addition of sand and compaction several times to ensure the joints have sufficient interlock between the pavers.
    • Finally, clean off any remaining sand.  If you use polymeric sand (see below), follow the instructions carefully.  If you like, you can also seal the patio to protect and enhance the appearance of the surface.
  • So, what’s the big deal about joint sand?   Many of the problems with patios come from the use and proper installation of the joint sand.  Distinctive Patios uses premium polymeric joint sand on all of it’s paver installations.  This is special sand that has a polymer dust added that when activated, binds the sand in the joints between pavers.  It’s primary function is to improve the interlock and therefore the durability and stability of a paved surface.  It also makes the joints resistant to water washouts, ants and weeds.  We’ll have a more complete discussion on this topic in a future post.