We do not do much utility installation, but I have a good customer that wants me to bid their underground utilites for a new house and barn. It is approximately 2640 ft long and digging 42" deep in sandy clay. I will be digging with a SK 200 and a 32" bucket, then laying direct burial electric line on one side of the trench and the water line (electric line and water line not to be included in bid) on the other side. Then backfill trench. We will also use a trencher and trench another 725 ft. How would you guys bid these jobs? Thanks for your help
bidding since you know how deep and how far it is just plugging your per linear foot number in. for water we have certain p/l/f depending on what type of pipe and how deep and how many crossing's you have. electrical is the same. water and electric in same trench never happen here. all water is minimum 6' and may be 8' deep. electric is 4' for primary and may be 2' for secondary. sounds like you have the equipment and need to figure out some unit prices. good luck. regards, cd
OK, the only thing I excavate for a living is tooth decay. But. . . I do have experience in hwy, commercial, and residential grading and utilities. Here in Tennessee and in my former life working for a civil engineer in Kentucky, I have never seen water, electric, or gas lines that deep. For residential water supply, most local codes specify "below the frost line". We used 16" minimum depth for water in Lexington; suprisingly, the "frost line" is specified as only 12" deep here in the Knoxville, TN area. Obviously, you will need to check the local codes. Disregarding the minimum spec, I dig all my water lines 18" or greater, and 24" for electric, and 16-18" for residential/farm gas lines--and deeper if there is any prospect for future grading over the lines that might "reduce" the depth later. The problems you get into with going deeper than the local frost line is the availability of "boxes", i.e. in-ground utilty valve or junction boxes. (I bet they don't have any boxes spec'd or procured. . . it's often an afterthought.) I like water valves--full-opening 1/4 turn ball valves every 500-1000 ft or so, especially on a residence/farm site that might need future taps. For that length of line, I hope the wner is savvy enough to run full 2" Sch 40 PVC all the way to the home/barn site, for optimum flow and "working pressure". Many local codes offices don't require it, but always use a trace wire in the ditch with the (PVC) water line. If the ditch is deep, keep the trace wire no deeper than say 24". I don't know if there is a local separation spec, but we always separate ditches for water vs. electric. Three ft. will do in a pinch, but I want them 10' or more apart on my farm--mine are across the driveway from each other. There will be a time (maybe many times) over the life of the farm that someone will want to tap the water line, and I don't want to dig around the electric line. I can't help you with the pricing, but if this is a good customer, share your expertise and talk them out of the Type UF direct burial cable, and get them into PVC conduit. Here in Oak Ridge, the city has many subdivisions that had direct burial cable installed in the late 1970's and early 1980's. . . and they are having to replace it all, now with conduit. You won't find anybody using direct burial on anything they plan to keep around here anymore. I don't have electricity at my barn yet, but that's on the list for this summer. PVC conduit, 24-30" deep. Have fun. Hope you make a buck or two.