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Steel Bridge Painting - Cost Estimation

Steel Bridge Painting - Cost Estimation

Steel Bridge Painting - Cost Estimation

Good afternoon. First time here. I'm a municipal-civil engineering, dealing with smaller scope projects typically, local roads and bridges and such. Also an NBIS inspector, which is where the question arises from.

We have a client looking for a very general cost estimate for blasting and re-painting a ~70 FT x 10 FT pedestrian bridge.

Typically with our bridge inspections and projects, very few steel bridges are utilized as the State owns 95+% of bridges large enough to warrant steel girders. On the other hand, the few clients of ours that own pedestrian bridges are constructed of weathering steel and do not require re-painting.

What I am hoping for is that someone on here has some very, very general method of cost estimating this type of work. I have no problem estimating the additional costs (like pulling off the deck, which they will need to do), but I do not know where to start on how to estimate painting costs.

Thank you in advance for anyone that can provide any input.

RE: Steel Bridge Painting - Cost Estimation

Contact a local contractor and get an estimate. You should get an idea of the type of coating you want. Sand blasting and zinc rich epoxy primer and polyurethane top coat for example, or a quick drying structural primer and a quality top coat (likely the least expensive).


RE: Steel Bridge Painting - Cost Estimation

Does your state DOT have pricing available? There's more to it. What is the existing coating, lead-based paint? Are you overcoating or going down to bear metal? If you are overcoating, check existing mil thickness. If you have 12 mils overcoating may not be advisable. Removing lead paint requires a containment structure. If your bridge is over traffic and the containment has to be removed each day, it probably triples the painting cost. Is spray painting allowed in your area or roller and brush only.

I know I gave you a lot to chew on. I'll look up some pricing tomorrow.

RE: Steel Bridge Painting - Cost Estimation

Thank you to dik and bridgebuster for their responses. Bridgebuster, I thank you for your response but I'll also share some information I learned today that will hopefully save you some unnecessary leg work that you offered.

I reached out to another bridge inspector that is also a designer for a much larger and solely a structural firm in the nearby large metro area. He inspects some 50+ similar bridges bi-annually for the metro areas forest preserves. For these shortspan, prefabbed ped bridges, they are literally considered "set it and forget it" bridges and are assumed to have a 25 year life span (for the rusting concerns mentioned...whether painted or done with weathering steel). So they're basically considered just to have a $4K annual cost assuming they are replaced every 25 years since most have a prefab and install cost of under $100K.

He advised that re-painted costs typically exceed 60% of the replacement cost, and therefore the prospect of repainting a bridge like this is considered wasted money. He advised that the most cost effective method of inspection/replacement advisories is to ignore the rust on the secondary members (which have much much smaller sections) and key on rust on the primary members. When those really start to lose sections, that's when you immediately advise on replacement.

Thankfully my bridge still has minimal section loss on the primary load bearing members, so we will simply be advising a more frequent inspection cycle with the explanation above.

I also did reach out to a contractor today, but will be emailing him tomorrow to call him off before he wastes any time.

Thank you again for both your input. I wanted to leave the explanation above for anyone who runs across this in the future.

And also, with this being my first post to this board, very pleased with and thankful for the responses. I will be sure to frequent this forum a bit more often with what I can contribute to.

RE: Steel Bridge Painting - Cost Estimation

What sort of specifications do you have? If none, see if the DOT has a spec that you can adopt. The environmental stuff also may have to be bounced off your state agency environmental group. No point in missing any of that at this stage, because later you don't want to be in some legal argument with activists.

RE: Steel Bridge Painting - Cost Estimation

"...He advised that re-painted costs typically exceed 60% of the replacement cost..." I am not convinced about that statement, otherwise, the Arrigoni Bridge connecting Portland and Middletown, Ct. would have been entirely replaced back in the 90's when the bridge was stripped of its lead paint and repainted following our rehab work.

RE: Steel Bridge Painting - Cost Estimation


I would not be convinced about it either....otherwise we would never see a single highway bridge have its girders stripped and repainted.

This recommendation (and estimated cost %'s) applied to "...these shortspan, prefabbed ped(estrian) bridges...." only.

RE: Steel Bridge Painting - Cost Estimation

NWIeng, as a 25+ year construction resident engineer, I will tell you that for bridge painting, there is no "plug number" based on SF of area, and I wouldn't trust any book-value that someone might want you to use. You really have to look at all of the general condition-type costs that the painter may encounter and consider those as part of the cost development process. Traffic control, site access, time of day for work / restrictions, waterway or roadway below, type of access equipment needed (lifts from below vs. snoopers from the top)? Are you just doing fascia girders? Diaphragms & interior girders? Are there handrails & detailed elements that will require more detailed blasting & surface prep than girder faces? Will the entire bridge be accessible or will multiple mobilizations be needed?

Summarily, there are a lot of variables that will drive the cost that an "off-the-shelf" plug number can't anticipate. The actual application requirements for primer & paint, as dik mentions above, play into the cost, but the money on bridge painting contracts isn't driven as much by the materials as it is by the labor & equipment costs.

I can turn you onto an estimating tool that might be of aid if you want. Hit me back on the thread, maybe I can help.

RE: Steel Bridge Painting - Cost Estimation

Would have to disagree on letting the paint go until replacement. At some point, the bridge will look terrible and be an eyesore long before replacement is required.

Some typical costs are $5 to $25 per square foot for spot coating, $3 to $25 per square foot for an overcoat, and $15 to $25 per square foot for complete paint removal and repainting.

Estimate for cost of new bridge:


RE: Steel Bridge Painting - Cost Estimation

Bimr, simply as a matter of professional debate and not as means of trying to starting an "Internet Troll Argument," I have to throw a huge caution flag on using any of the "plug numbers" that you have provided.

Using plug numbers might work for concrete pavement, storm sewer, pavement markings and similar units of work that are consistent in scope and construction methods, however, the bridge painting project that NWIeng is looking at is definitely NOT in this category. Simply look at the example projects at the website you referenced: The site logistics & conditional variables for all of the bridges pictured are vastly different. Understanding how a unit price is developed, particularly when the scope of work depends on site-based operational variables, has to be considered in developing an estimated cost. A book value may or may not incorporate site-born variables, and that's the point: How can you rely on a number when you don't know what it's based on?

Owners, DOT's and our clients hire us for our expertise. It makes me cringe when I ask a young engineer to validate a unit cost for a complicated work element and they tell me that they found it in a book. Until you've had to be grilled by an owner for an under-stated, or over-stated cost estimate, you haven't felt this sting. It does no one any good to, say, take the high unit cost because that will force the owner to budget high for it. While it might be a safe play for the engineer, it might force the owner to encumber more funds than he needed. And if he's done this on a loosely-assumed notion, then the engineer hasn't provided the service that meets the Standard of Care our community is responsible for. And the same is true when your estimate is 35% under budget and the owner is scrambling for funds and wants your insurance carrier to chip-in on the overage. No bueno….

When the scope of the work is unclear or varies because of site constraints, the engineer needs to put the Means Construction Cost Index books away and take the time to develop labor, equipment & material cost estimate, plain and simple. This bridge painting example IS a case for this point. When you generate your own detailed estimate, you will be able to give the Owner a cost estimate that reflects your complete understanding of the scope of work. And that's what he hired you for.

OK, end of rant. Bimr: Thanks for the platform. No hard feelings, of course - We get better as an industry & as a profession when we debate. Cheers!!

RE: Steel Bridge Painting - Cost Estimation

Would think the numbers are adequate for a ball park estimate. Ball park estimates are +/-50%. He is asking for a "very general estimate".

Would think the poster is smart enough to understand that the cost range of the cost estimate would very from a simple task to a complex task.

If you want a detailed estimate, the scope of work has to have some definition.

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