[fitzg2md]

I am bidding a job as a sub for a paver repair. Basically, because of construction, a section of roughly 1400 sq ft has been ripped out. The pavers are the large grids...about 2 feetx2.5 feet or somewhere around that. The type that has soil in grid. It is a parking lot type area.

The existing pavers have a base and are set in an inch of sand, but I am not sure how deep the base goes. Since this will see auto traffic, I am planning on a 12" base for the new area. I am also not incredibly confident that the soil is anywhere near virgin soil. Does anyone forsee a problem where the new pavers meet up with the existing ones? Also, if this soil is loose due to construction, how far down do i need to excavate? There was a 30 foot deep (!) trench that was put in to deal with wastewater run off for enviromental purposes, and I am worried about the fact that the ground isnt compacted like it should be. Any suggestions?

[Matt Kulp]

fitzg2md,

Sounds like a fun one!

First, where you are meeting up with the existing paving. You are sure to see a difference down the road, due to the difference in base construction. If the previous installer put the same amount of base as you are planning, you may not see much difference in the transition area. But, you may want to put a disclaimer to state what you are and are not responsible for.

Second, you asked about the loose soil. You have to dig far enough down to get to a compacted subgrade. There is no way around it. If the soil settles, so will the paving above it. As far as the 30' deep trench. I would try and get some information as to how it was backfilled. If you do not feel comfortable with the compaction of the trench, you need to make the decision as to what guarantee you give the customer as a result of the previous work. In most cases, the excavator or whoever dug the trench had to have the backfill inspected for something that deep. If that is the case, then I would feel a little more secure with the compaction of the trench. If it was not inspected, I would just be honest with the customer and tell them they can expect some movement over the next 3-7 years.

I know this is not a clear answer, but I think in this situation you just need to have all your angles covered as far as responsibility in your contract. Unless the customer wants you dig the trench back out and re-compact!

[fitzg2md]

thanks matt. i did tell the customer that he should expect some settling in relation to the existing pavers. I just want to minimize it as much as possible. The trench is a nightmare. Has something to do with wastewater runoff prevention. They brought in the biggest trencher in the entire USA to make the trench. Then they filled it with a huge mix of crap...dont remember what, however chicken feed was one of the ingredients. Dont ask me why???

Im just going to have to be very blunt and make sure they expect some settling. Government contracts sure can be a pain in the arse!

[Dale Wiley]

Chicken feed ??

30 foot deep trench ??

I see the whole thing sinking to China...What were the specs on the trench install ??

Around here the norm is getting 98% compaction, with compaction done in 6 inch lifts / increments... but a 30 foot deep trench is some major excavation. We probably would not even top that off until at least a year had gone by.

I would form a separate LLC to do the job, then dissolve it after the job is done and your paid...

[fitzg2md]

hahaha! thats the best advice yet!

yeah, they used some weird mixture that is made to filter "unidentified contaminents" from the ground water before it runs off the base. They trenched it about 6 feet wide and 30-40 feet deep and nearly 100 yards long. The group that did it is a pretty large national engineering company, so you would think they know what they are doing with the compaction...i just dont trust it. Im just gonna be extremely blunt. Let them know that there is a good chance of serious settling in places, and reccommend NOT doing it.

But if they want a bid anyways, ill just tack on another 500 for me to get a lawyer to put special clauses in my contract

Or perhaps like dale suggests...put the bid in under the name "fly by night, llc." haha

[Paul]

You might be dealing with an engineered soil that will support the grass pavers. I would check with the company first if your not sure.

[Greensmith]

chicken feed might be corn gluten pre-em.