There is no single price for a rock bag, because the bag is only one part of what you pay for. The cost of a job depends on how many bags the design needs and in which size, where the fill rock comes from, how the bags are filled and lifted, how far everything travels, and which documents the specification asks for.
That is why we do not publish a price list. A price per bag on its own would not tell you what your project will cost. Send the drawings and the design current velocity, and we will price the job from them.
What drives the cost
| Cost driver | What decides it | What helps |
|---|---|---|
| Bag size and number of bags | The design current velocity at the bed, and the length and width of the area to protect | Give the design velocity and the extent from the drawings, so the size is not larger than it needs to be |
| Fill rock | The grading for the size (50 to 200 mm, or 75 to 200 mm for the 8 ton bag), the source, and the haul distance to the filling area | Name the nearest quarry or crushed-concrete source the specification allows |
| Filling | A level filling area near the site, filling frames, a loader and a crew, and the number of bags | Say where bags could be filled and stored near the site |
| Lifting and placement | Crane or excavator size and reach, working in the wet, and survey, diver or ROV checks of the placed bags | Give water depth, access and how close lifting plant can stand to the work |
| Transport | Distance and route to the filling area and the site | Give the project location or delivery point |
| Documents and testing | What the specification asks for: data sheets, method statements, fill test results, as-built records | Send the specification or the submittal list with the enquiry |
What a quote should state
Two quotes are only comparable if they cover the same scope. Check that each one states:
- The bag size and the number of units
- What is supplied: empty nets, filled bags, filling frames, lifting gear or site support, and what is left to your contractor
- Who supplies the fill rock, to what grading, and who fills the bags and where
- Whether placement is included, and with what plant
- The delivery point, and who pays transport to it
- The documents supplied with the order
- What the price assumes about access, water depth and working hours, so a change on site is easy to price
What to send for a quote
You can attach drawings and photos to an email to info@evosnt.com, or describe the job in the form below and we will ask for what is missing.
- Drawings or a dimensioned sketch of the area to protect
- Design current velocity at the bed, or the hydraulic report; wave conditions if the site is exposed
- Water depth, and bed and bank material
- Photos of the site and of any existing scour
- Access for a crane or excavator, and whether the work is in the wet
- Project location or delivery point
- The specification or tender documents, if there are any
- When you need the bags on site, and whether this is planned work or an emergency repair
Why there is no online price list
A price per bag leaves out fill, filling, lifting, placement and transport. Those depend on the site, not on the bag, and they change from one project to the next. A figure on a web page would either be too high for a simple job or hide costs on a hard one.
A quote built from your drawings and design velocity is the figure worth comparing with riprap, gabions or mattresses.
Ways to keep the cost down
- Do not oversize. Pick the smallest bag whose rating is above your design velocity, using the size guide.
- Use local fill where the specification allows it. Bags can be filled with rock or crushed concrete.
- Measure by the number of bags placed, as in our specification clause. A count is quicker to check than a volume of loose rock.
- Put bags where they earn their cost: at the toe, around structures and in scour holes. Loose riprap is often cheaper on the rest of a slope. See rock bags vs riprap.
- If large rock is cheap and close by and there is dry access, riprap may be the better answer for the whole job. See when rock bags are the wrong choice.
Questions
- How much does a rock bag cost?
- We do not publish a figure, because the cost of a job depends on fill, filling, lifting, placement and transport as well as the bag. Send your drawings and design velocity and we will quote the project.
- What gives the most accurate quote?
- The design current velocity at the bed and drawings of the area to protect. Together they set the bag size and the number of bags, and most other costs follow from those two.
- Why do two rock bag quotes differ so much?
- Usually because they cover different scopes. One may include fill, filling or placement and the other not. Compare them line by line against the list on this page.
- Can I ask for a quote before the design is finished?
- Yes. Send the location, the area and the best velocity estimate you have, and say that the design is not final. The quote will state what it assumes.
Published by EVOSNT Trading FZCO, manufacturer of EVO Rock Bags. Product figures are from our technical specifications. General guidance only; the project engineer is responsible for the final design.
