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Bidding on a retaining wall contract, are my numbers ok?

Discussion in 'Landscape Architecture and Design' started by swing blade, Jan 8, 2005.

  1. swing blade

    swing blade LawnSite Member
    Messages: 123

    Hi guys,

    I've been searching this site in hopes of finding info on retaining wall bids. Currently I am bidding on the following:

    Customer has a sloping backyard which he wants to level off so it is more useable to him. the proposed wall is 50' long. The height of the wall is 4' high above ground. I am planning to install 1 row of block below grade as a footer, then 42" high of block, and then the row of capstone(6" thick) to top it off. The block are from reading rock; demensions are 16 5/8" wide 12" deep and 8" high. If my math is right the number of block per row would be 36, and there would be 6 rows of block and then a row of caps. I am planning on backfilling the wall with 1" roundstone gravel the entire length and on foot back from the wall and 40" high with shredded topsoil on top of that. there will be a 4" drain tile in the gravel with multiple drainage points. I then have to backfill the area 34' back to create a level terrace in the yard. I have run the numbers so many times in my head that I am unsure of myself and would like for some of you to please double check my math:

    block cost: 3.85 ea. need 228 877.80
    capstone cost 4.20 need 36 151.20
    drainage pipe 30.00
    Gravel cost 9.35 per ton need 9 ton 84.15
    fill dirt cost 12.95/yd delivered need 80 1037.17
    topsoil cost 19.95/yd delivered need 40 798.00
    bobcat rental cost 160.00 per day need 2 days 320.00

    LABOR 1800.00

    TOTAL 5098.32

  2. cgland

    cgland LawnSite Bronze Member
    Messages: 1,929

    You are forgetting a couple of things.
    A) Modified aggregate for base (your buried block is NOT a footer, you need to excavate to 12"-14" below grade to accomodate your base & block)
    B) Separation fabric to wrap the excavation and "separate" the subsoil from your base & backfil.
    C) Glue for your caps
    D) Most importantly, GEOGRID! You will absolutely need a min. of 2 pulls.
    E) Do you have a vibratory plate for compaction? If not rent one!
    F) With the drainage pipe you will need T's to bring it through the wall
    G) How many days do you propose this project will take, because $1800 seems pretty cheap for labor.
    H) Are you adding anything for profit? material mark up?
    All of these things are necessary and they add up. It could be the difference between making a profit and losing your a$$.
    My bid would be around $9,500 not including seed/straw or hydroseeding.

  3. kris

    kris LawnSite Bronze Member
    from nowhere
    Messages: 1,578

    I didn't even touch your materials ... so I don't know if your wrong on that.

    Are you experienced? How many man-hours are you figuring? How about access... it's going to be torn up with the Bobcat ...are you counting on that?
    How many hours trucking? I'd count on that machine being there another day.

    I believe you are WAY to low on your labor. I'm not going to take the time to estimate this but my guesstimate would be over 10K.
  4. diversified-1

    diversified-1 LawnSite Member
    Messages: 5

    Well as far as labor I'd do it for that $1800. One good point brought up is the footing. Spend the extra time, without a footer it will not last. You will need at least a 8" x 16" footer, possibly deeper depending on your freeze line. I'd figure around 3 yds. concrete and the added cost of the bobcat or whatever to dig it for an extra 2 days. The concrete will have to cure a couple of days before continuing. Figure that in also.

    I know most of the guys on this forum are "professionals" but $1800/40 hrs= $45 an hour. Forty hours should cover this project if you are proficient at running equipment and stacking blocks.

    I live in West Tennessee and $45-50 an hour is what I charge for my 580L backhoe or my komatsu D37 dozer. So why would someone charge an arm and a leg for services when everyone will be happy with a Quality job at a Fair price? I also live in an economically depressed area so take that with a grain of salt...

    West Tennessee Diversified Services... :waving:
  5. kris

    kris LawnSite Bronze Member
    from nowhere
    Messages: 1,578

    I don't beleive this guy will do this job in 40 man-hours. I'd count on double that.
  6. mbella

    mbella LawnSite Bronze Member
    Messages: 1,284

    Milo here's my 2 cents:

    1) Does the backyard slope end where you will be building the wall or are you cutting into the slope? If you are cutting into the slope then your wall will have toe slope. You need to account for this when determining how much block to bury. If you do have toe slope, I would suggest burying at least a block and a half.

    2) How are you going to be excavating for the leveling pad and buried block? At a minimum (with no toe slope) I would be excavating 2' wide x 14" deep. Someone else commented of "freeze line". Freeze line has nothing to do with the type of wall you are building. Are you doing this by hand or use a machine? The bobcat won't do it (unless you have the backhoe attachment=more money).

    3) If you don't own a saw, you need to allow for one (caps, end blocks).

    4) Bobcat Rental. I would plan on having the bobcat everyday that you are on the job except for the first day, if you don't use it to dig for the leveling pad. You should backfill as you build the wall, you're going to need the machine.

    5) Permits/fees. Generally, any wall over 4' needs a permit. Your wall is 56" tall. Check it out.

    6) Labor. I'm with Kris on this. You should have at least 80 man hours in the bid for this job. Someone else replied 40 hours. No way! That's 2 men in two 10 hour days. Absolutely no way. I'd bid it over 100 man hours for the entire job.

    I don't know how much experience you have, but this wall isn't a fun little gravity wall that is good to learn on. 56" might not sound like a lot, but it's enough to require geogrid and a permit (where I live) and enough that you could get yourself into trouble. If your customer decides to put a child's playset on top of this thing and you don't build it right, look out.

    My price would be over $10,000.00 for everything, including a warranty.
  7. landscapingpoolguy

    landscapingpoolguy LawnSite Senior Member
    Messages: 822

    I would be more around $7000.00 200 sq ft wall $35/sq ft

  8. mbella

    mbella LawnSite Bronze Member
    Messages: 1,284

    What about the soil work?
  9. cgland

    cgland LawnSite Bronze Member
    Messages: 1,929

    "I would be more around $7000.00 200 sq ft wall $35/sq ft"

    That is also exposed height. What about your buried block? Does that include geogrid? I think you should sharpen your pencil. And as far as 40man hours....no way! and if you can, I would like to sub you out on every job I get, because you must be kick-a$$! :cool:

  10. lawncare4u

    lawncare4u LawnSite Senior Member
    from S>C>
    Messages: 399

    There is no way you cn do that big of job for $1800.00 pay labor and make money! That is a huge job and will hae a few unseen things come up! Be safe Do as a couple of others sugested...........$10.000....plus not minus

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