Hey 2Beast - Raising Paver Walk

[brnhornt]

Hey gang.  I have a sagging front walk issue and looking for some opinions.  This was a project that we were going to completely rip out and replace with the fantastic help of 2Beast's crew with the design, however that money was moved into replacing a larger patio on the back of the house.  So now I'm back to trying to fix this.  Here's an overview of the whole thing:

   

The driveway side has settled about 1/4 to 1/2 of an inch.  The middle section is fairly good.  The side by the front porch is the problem.  I built a simple step out of a 2x4 and some plywood, but you can see it needs to come up the full 2 inches over on that side:

   

It looks like these pavers have been set onto a 4" concrete pad.  I have only dug in one space....but I would think it's natural to assume it's 4" all around:

   

I had a concrete leveling company out the other day, and he was a touch worried about trying to raise the pad.  But mentioned that if I verified it was 4" think, it should be ok.  Looking around 500 bucks for them to do that.

Any other ideas?  The pavers are old and showing their age, but still serviceable, so I really don't want to rip them out and start anew.  Is pumping the pad up the best way?  Or, is pulling the pavers, cleaning the pad, and then putting down crushed lime or some other aggregate, and set the pavers back down a way to go?

Only downside I can think to the aggregate idea is the walkway was originally being held in by plastic and rebar.  That has shifted and many of the joints have opened up.  Since there is concrete, I was going to use adhesive and glue down the solider course and let the middle float.  If I level with aggregate I'd obviously have to move back to an outside/external anchor of some sorts.

Thanks for any input!

[brianwelch]

It should be pretty easy to pop a couple of the pavers and drill the subbase to confirm the thickness of the concrete setting bed. 
I also think that the uniformity of the settlement indicates a somewhat rigid bed...If just on gravel or aggregate, the walk would probably be all-over-the-place...
Some "exploratory surgery" will give everyone a level of comfort as to what to expect...

[Bob10]

The outer brick and the step sit on a 8"x12" rebar reinforced for lack of a better word beam.  The center is filled with compacted #2 base that allows for drainage the perimeter stops any movement in pavers an inch of compacted sand makes setting them level easier

[2beast]

I will answer when I get to a real computer
Tough for me with a phone

[brnhornt]

It should be pretty easy to pop a couple of the pavers and drill the subbase to confirm the thickness of the concrete setting bed. 
I also think that the uniformity of the settlement indicates a somewhat rigid bed...If just on gravel or aggregate, the walk would probably be all-over-the-place...
Some "exploratory surgery" will give everyone a level of comfort as to what to expect...

Good point and sure enough....it's not concrete the whole way.  The last three feet or so towards the driveway is base....

[brnhornt]

I will answer when I get to a real computer
Tough for me with a phone

Completely get that.  Thanks!

[2beast]

From the looks I would probably just pull the pavers back to where the elevation looks good.
Add a base of clean 3/8 chips and re-level.
Use clean gravel and not sand or fines.
Sand or fines will move as water passes through them whereas clean gravel will allow for water movement without displacement.
Since it all has settled, add soil back up to grade and reset your paver restraint.

[brnhornt]

From the looks I would probably just pull the pavers back to where the elevation looks good.
Add a base of clean 3/8 chips and re-level.
Use clean gravel and not sand or fines.
Sand or fines will move as water passes through them whereas clean gravel will allow for water movement without displacement.
Since it all has settled, add soil back up to grade and reset your paver restraint.

Thanks!  Think a hand tamper is enough for the task or would I need to rent a compactor?

[chrisntam]

If you’re going to all the trouble to fix it, why not spend the additional $90 to rent the tool for proper compaction? I just put in about 350 sf of decomposed granite using the rental compactor. I also have a hand tamper that really didn’t do much. If you want it compacted, get the rental. It’s heavy you’ll need help loading and unloading.

[brnhornt]

If you’re going to all the trouble to fix it, why not spend the additional $90 to rent the tool for proper compaction?  I just put in about 350 sf of decomposed granite using the rental compactor. I also have a hand tamper that really didn’t do much.   If you want it compacted, get the rental. It’s heavy you’ll need help loading and unloading.

Good point!