Frequently Asked Questions

1. What are the requirements for forming a driveway/sidewalk?

The forming lumber should to be the full depth of the proposed concrete, the sub-grade needs to be stiff compacted soils, and the inspection needs to be called in the day before you place, and all formwork must be completed before the inspection.

2. What kind of fill can be used in driveways/sidewalks?

Compacted DGA (Dense graded aggregate) is recommended for use under driveway aprons and sidewalks.

3. What strength of concrete should I use?

A minimum 4000 psi, 6% air entrained concrete placed at a 4 inch maximum slump, must be use.

4. How far back should my sidewalk be from the curb?

Our standard is 4 feet from the back of curb unless otherwise approved.

5. What kind of slope should my sidewalk have?

The sidewalk profile should follow the street, the cross-slope is ¼ inch per foot or 1 inch in the 4 foot width.

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6. How far above the curb should my sidewalk be?

The front edge of the sidewalk should be 5 inches above the curb. The sidewalk can fall either toward or away from the street.

7. How deep can I install P.E. Pipe?

Installation depth can be dependent on several factors. Check with your engineer for their design.

8. Can I use gravel for my pipe backfill?

Granular fill is required. Pipe installation specification ASTM D 2321 will tell you how much compaction effort is needed for different soil types.

9. Do I need to compact the backfill around my pipe if its not in the right of way?

Yes. ASTM D 2321 is the required pipe installation specification. Within the R/W there are additional requirements for compaction of the trench backfill material above the pipe.

10. If the drawings call out CMP can I use PVC or PE pipe?

Due to the hydraulic calculation preformed by the engineer, we are not at liberty to very from pipe types called out on the plans. Changes must come through the design engineer.

11. How deep can a catch basin be before I need steps?

Every structure 4 feet and deeper measured from the outlet invert to the top of the casting must have steps 12 inches oc.

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12.How deep can I install 2x2 yard drain?

Do to the inability to install steps in the 2x2, depth is limited to 3 feet.

13. Can I use corrugated p.e. pipe for an under drain?

No, the pipe must meet current sub-reg specifications such as perforated SDR 35.

14. The sub grade is low can we bring it up to grade with gravel?

Only under sidewalks, all other sub-grade preparations must be uniformly compacted clayey soils.

15. Do I have to seal the transition between the blacktop surface and concrete
curb?

Yes, a hot pour elastic type sealant or approved equal is required.

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