A local contractor wants me to bid the excavation for the footer and slab as well as backfill, compaction and final grade. There is about 350 ft of footer, 4' deep using a 2' bucket. There is only about a 4" cut for the foundation but I have to scarify and re-compact everything. I have never bid a job like this before and really dont know what time frame I am looking at for completing the entire job. I will be digging the footers with a JD 310 and I thought about taking my skid to do the areas of the foundation where I cant get to. Can anyone help me out? I dont want to go broke on this job and I need all the help I can get with the numbers. Also, the site is about 4 hrs away from the shop. If that makes any difference. Feel free to PM me if you would like and I can go into more detail.
Why? I can see stripping the topsoil and maybe having to build things back up to your final grade, but if you can get to your final grade by just cutting existing material, what benefit is there to scarify and recompact? First I would prep the pad and do the 4" foundation cut, leaving just enough around the edges to give the TLB something to sit on to keep things level. I would use a skid, but that's just becase I'm more comfortable in a skid than a TLB for cutting a grade like that. If you're comfortable with the TLB, then you could use that. Either way, I would think you can have the pad prepped in half a day. My estimate would be 2 days to dig the footers, and clean up the edges of the pad. Assuming the material you're digging is suitable, some of it could go back on the pad to get you to your final grade if needed, and I assume the rest of it is just going to go outside the footers to be used later for backfill and final grade. If you've got two machines on the site, then the digging can be done in parallel with prepping the pad. This is the way I prefer to do it so that each machine has a dedicated task, and production can be maximized. Backfilling and final grade would be another half day. Could use the TLB, or a skid, or a dozer, etc. Total time is about 3 days, but it's broken into two pieces: 2 1/2 days to prep the pad, and dig the footers. This would be at least a two-man crew, and if the compaction work is substantial, you might want a 3rd guy. The other 1/2 day would happen after the foundation is done to do backfill and grade. This could be a one-man job. This makes a hugh difference. Your mobilization costs are going to be quite high. Also, since you're looking at a multi-day job with a 4-hour commute each way, it's going to make for a couple of really long days. It might actaully make more sense to drag your equipment to the site, and spend a few nights in a motel then drag it all home when the footers are done. Then make a return trip to backfill and grade. Either way, these costs absolutely need to be factored into your bid, otherwise all your profit is going to go into paying for your gas. PM me if you have any questions. Joe
I think Electr Glideis pretty close. Unless you can haul both the TLB and skidsteer on the same rig I would just take the TLB. The killer on this job is the 4 hr commute. Unless the contractor is paying for 4 hrs of lost time each way and overnight stay there is no way to make money on this job. I have hauled my Skid steer and Mini-x a couple hrs to my cabin and done jobs for others but I had a free place to stay and I was going for the weekend anyway.
Any time I have more than 1/2 hour travel time to a job, I figure the extra time as a job expense and add it to the quote. If you can't do this, it's not worth taking the job, you'll make more money locally.
Thanks for all the input! The contractor told me that I am the only one he is considering for the job and that I should include my travel time and hotel costs into the bid. I have all the numbers worked up but I feel that it is too high. This is my first job for this contractor and I would like him to invite me back! I would really like to PM those numbers to some of you guys and have you look at them to tell me if I am in the ballpark. If that would be OK, let me know.
Copenhagen, I'd be happy to look at them. Send me a PM. The more detail the better. If you've appropriately included your travel time, then your numbers will be high. That's a good thing...:thumbsup. Don't worry about the cost. If he invites you back it should be based on the quality or your work. Also, if you work for cheap the first time, then that's what he'll expect the next time. Joe
Just another thought--would it be more economical to rent a skidder locally than to spend 8 hours hauling yours to and from?
maybe i'm reading this wrong, but if he has to backfill AND compact.........350 l.f. of footings 4' deep.......... 1/2 day is waaaaaaaaaaaaay short time wise, isn't it?
Agreed. However, most of the GCs in my neck of the woods are not keen on compacting backfill against new foundations for fear of cracking or bowing. We would just put in a 2' trench with no overdig, and the footers get poured in the bottom with no forms. After the 8" block is layed-up, they just want you to backfill it and don't worry about compaction. That's where my 1/2-day estimate came from. Now if the GC wants compacted fill, I guess you then have to put in a sufficient overdig on each side, bring in your lifts, and alternate inside and outside to not put too much stress on the wall. Yea, that's going to take a lot longer. Dayexco, is that what you're thinking? Joe
I asked the GC that. The plans call for 12" wide footers. I asked if they form them or if they just pour in the trench. They said they form them and to bring my 2 foot bucket. Seems like a waste to me, but...:notworthy . You know how some GC's are.
I know for the residential codes, if there is any living space, then the footers must be formed. Also, what method of compaction will you be using ??
yup, exactly. we'll start in the corner, compact with a 690 and vibratory plate, pack both sides equally to avoid bowing/cracking wall...put enough dirt on wall where we start not to damage with track of excavator...straddle the wall, and compact our way down the wall, compacting both sides in equal lifts. goes fast, works great
Perhaps it's that area of the country, but I've never seen footings only 12" W. Most around here are at 18" minimum, average is 22" - 24". You may want to confirm this.
I think it is the area of Colorado. It is up in the mountains and the soil is pretty stable. I think there is a lot of crushed granite on the ground. But I did check my plans again and it calls for 12" footers with 2" insulation on both sides. Thanks for looking out for me!
I was thinking about over digging enough so that we could get a jumping jack in there or I was going to use a shaker head on the backhoe.
Plate compactor should work fine.
On the issue of back fill, if the wall is poured or block is big difference. On poured walls I think you could get away with compaction on the inside only if a floor is to be poured. Block wall you should backfill both sides at the same time. On the outside of the wall you could just back fill if you have just topsoil cover. Find out who is installing insulation board and vapor barrier. Also find out if the plans call for any drain tile. The slab prep might have to be checked for compaction around 95%. When digging footing check grade allot should be with in 1/2" so the mason uses as little concrete as possible. Contractor could charge you back for extra concrete used in footing and slab. Backfill material for the inside could have to be imported in and not material on site. Ask the contractor to pay for all material and you do the labor. Sounds like around $6k to $8 in labor and travel or more to me.