How often are seal coats applied to parking lots
How often are seal coats applied to parking lots
(OP)
I am looking at a report on parking lots for a client with about fifty school facilities done by another engineering firm. The report contains a repair forecast.
The report has most of the parking lots to be resurfaced within the next few years. The resurfacing is to consist of milling 1.5" and repaving. I haven't seen most of the parking lots but this seems reasonable for the age of the facilities.
The thing that strikes me as strange is that the report calls for sealing (I assume asphaltic slurry sealing) three years after the resurfacing and every three years thereafter.
I only have access to part of the report and this is about all of the information that I have, so I'm mostly just curious.
I've done asphalt remediation before from study to recommendation and construction, but I don't recall ever recommending a seal coat every three years.
If the construction is performed properly I would think a seal coat would not be necessary for 7 to 10 years depending on conditions, but I haven't looked at this issue for a while.
Does anybody have an opinion or web resource that might be helpful?
The report has most of the parking lots to be resurfaced within the next few years. The resurfacing is to consist of milling 1.5" and repaving. I haven't seen most of the parking lots but this seems reasonable for the age of the facilities.
The thing that strikes me as strange is that the report calls for sealing (I assume asphaltic slurry sealing) three years after the resurfacing and every three years thereafter.
I only have access to part of the report and this is about all of the information that I have, so I'm mostly just curious.
I've done asphalt remediation before from study to recommendation and construction, but I don't recall ever recommending a seal coat every three years.
If the construction is performed properly I would think a seal coat would not be necessary for 7 to 10 years depending on conditions, but I haven't looked at this issue for a while.
Does anybody have an opinion or web resource that might be helpful?





RE: How often are seal coats applied to parking lots
cost is $0.03 per sq ft counting sweeping, sealing cracks, sealing pavement and re-striping so it really is not a big deal
RE: How often are seal coats applied to parking lots
Is it possible that I am thinking of a slurry seal when what they are proposing is an emulsion seal coat? I would expect the emulsion seal coat to be more in line with your numbers, cvg.
I've never recommended those because it's basically like painting the pavement without providing any real benefit, although I can't say I've seen any serious research done. I suppose there is some very short term protection against moisture intrusion.
RE: How often are seal coats applied to parking lots
RE: How often are seal coats applied to parking lots
These costs are forecast out to past 2020, so it is at a very conceptual level. Who knows what oil will be in five or ten years?
I don't like Means much either, but I have a couple of bid sheets with unit prices that are pretty close to what Means is giving me in this case.
RE: How often are seal coats applied to parking lots
Your costs are a bit high but not completely out of line with properly applied slurry seal coat or microsurfacing. Spray-applied emulsion "sealcoats" are cheap but not worth the money....keep in mind that they also lower the skid resistance as compared to asphalt slurry seal coats which can be used to enhance skid resistance.
Routine seal coats are not necessary. Only use to prevent top-down water intrusion such as with cracks or to renovate the surface. You'll likely need mill and overlay prior to needing seal coat for oxidation repair.
RE: How often are seal coats applied to parking lots
We had a major industrial client ask us to do a review of their intermediate surface coating and found that even crediting the pavement with some amount of extended life by surface treatment coating, the rolled up costs back to year zero were essentially the same. They had us look at the same 20 years for a straight 1.5" mill and overlay versus say 25 for the same but with periodic seals.
The other part of the equation not to miss, AESTHETICS. It looks nice and fresh, so to 99% of the public they have a "new" parking lot every four years. Even though you have to re-stripe the parking stalls, normal paint would probably age at the same frequency. All and all I'm neutral on it from engineering warrants but can see the benefits for retailers and the sort.
RE: How often are seal coats applied to parking lots
RE: How often are seal coats applied to parking lots
Ron, I appreciate the confirmation. Hope everything's going well for you.
eea, that's a good point about the aesthetics. I don't think it applies to schools, but being an engineer I always need to remember there are other things beside function.
RE: How often are seal coats applied to parking lots
RE: How often are seal coats applied to parking lots
I suspect the sealant industry wouldn't like him if he did.