Been considering an exposed aggregate patio.
Basically place and screed, apply the surface retarder, wait the magic amount of time (6-12 hours), then brush/power wash off the top layer to expose the aggregate in the pour.
Does anyone here do this routinely these days? Is it as “easy” as it sounds?
I also suspect it is critical (obviously) to know what aggregate is being used…i.e. some ready mix plants must likely have a “special” aggregate for exposure, although I suspect most don’t. We have to check…
Comments/suggestions are most welcome…
Thanks.
Replies
You've got it. Your ready-mix people will have at least one aggregate they routinely use. I think you'll want to float after screeding.
As for the retarder, you can do without it by brooming at the appropriate time if you're careful. Just don't head out for a long lunch. The finish will be more uniform with the retarder, if that's your goal.
I like it but people with small kids have issues. Hard on them.
PAHS Designer/Builder- Bury it!
Tom...hard on the kids... I guess from playing on it? How's it on bare feet? Three daughters here...
I guess my other option is a plain broom finish...but the exposed aggregate just seems soooooooooo much nicer...
I personally don't care for exposed aggregate finish. The ones I've seen are harder to keep clean than broomed and harder on the feet. Also, it seems that the process of exposing the aggregate takes away from a well done finish job by rounding off corners and such. I'm sure it depends on the aggregate used, but I've seen some up close that look like a kind of flint aggregate, ready to exact a toll on tender young feet. I'd take a lightly broomed finish instead.
As for kids, mine aren't here to vote on the matter, but they're still young enough that they tend to agree with me ... ;-)
my .02
The complaint I hear is of small kids falling and getting scrapes far more severe than would have been expected on plain concrete. Makes sense. Don't know what your ready-mix has for aggregate but mine (very small river stone) is very easy on the feet. Certainly something to check. Apparently you weren't planning on skating.
We normally have 12" of snow here. Freezes and thaws frequently, especially as I have insulation under my slab (part of PAHS). No problem with degradation for the last 8yrs. You'll want a control joint or two.
Broom cleaning would be a small problem, we blow. I much prefer it to a broom finish. Anybody stamping in your neighborhood? One ready-mix supplier here offers stamps. Or go with the aggregate and hope your kids learn fast to take it a little easier there.PAHS Designer/Builder- Bury it!
PIRGERBRUCE,
Did commercial concrete work long ago. Lots of ways to do exposed aggregate. One technique we used to save BIG bucks was use standard large aggregate and then spread quality aggregate on top by flinging it with a shovel using a fan type motion to get even spread and appearance.
Of the many different ways to do what you're looking for I'd say the most important element will be the size of the aggregate you want exposed. Any of the three main methods used will give good results, but remember, the smaller the aggregate the harder it is going to be to get good results. Because the smaller the aggregate, the easier it is to accidentally remove too much of the surface.
Unfortunately the larger the aggregate you want the more you'll have to pay.
I did a quick Google and came up with some great info. I advise you do the same as there is a huge selection of easily found info on the very first search.
Here is a quick link for some great info.View Image
Lots of Luck-- The more you know before you pour the better off you'll be.
PS-- ALWAYS ask the concrete company you choose for max input before placing the order. You'll find them a great help and have a lot better chance at coming out with a real great looking product.
Cork In Chicago
Thanks guys...Yes, I've been reading for the last couple of hours...LOL.
I do like the looks...over a plain grey broomed finish...although I do worry about the bare feet. My will be bare nearly always...but they're rough and tough. Guess I need to go find some.
Seems if it is a 1/2" round smooth aggregate....must call the local concrete folks in the AM.
Thanks!
EDIT: Searching more explicity for exposed aggregate bare feet reveals all sorts of swimming pool links...and they all mention a "perhaps less than comfortable surface"...
If it's like walking on #1 or #2 gravel....OUCH! LOL Argh...
Edited 7/10/2003 1:42:29 AM ET by PIRGERBRUCE
I dont' know where you are, but exposed aggregate sufaces don't hold up very well to the freeze - thaw cycle if you are in a very harsh climate. IMO
I did one years ago with a friend in the desert. We screeded, tamped, then seeded round washed rock into the surface and floated it in. It was a lot of work and almost got away. Looked really nice in the end and my friends love it. The washed round rock made a surface that wasn't as rough as many I've seen.Any jackass can kick down a barn, but it takes a carpenter to build one.
What part of the world are you at??, my experience with expose agg. is ,, it does not do well in a freeze thaw environment, freezing will pop those stones out, a little at a time. What size Patio do you have in mind?? If you do go with exposed agg. I reccomend the method of "broadcasting " stones on top of concrete. If you have the time, check with the Redi-mix company on who pours a nice aggracate finish, and possible, go and watch them do it. good Luck Jim J. ps, IMHO, it is not easy, can be done though
New York...Ithaca/Binghamton area...frost is a concern...in JUNE sometimes! LOL 32'x24' area...so not tiny at all.
Yes, as much as I think it would look wonderful next to the log siding and all the wood of this house of mine, I suspect it will be plain ole concrete...between the sore feet on the "softies" and the concerns of doing it nicely...until I cover it with some nice stone sometime. I'm leaving it a few inches "low" just for that purpose...and I'm putting in the Wirsbo HePex just in case...and did I mention the perimeter footers in the event it ever turns into a sunporch or something? And the conduit for the hottub sometime in the next 20 years...LOL.
My worst enemy is my planning ahead...too much sometimes I think!
Thanks guys!
How about colored and stamped concrete?Any jackass can kick down a barn, but it takes a carpenter to build one.
I'd love stamped...but its beyond the budget. I've stood on some that was just fantastic...and it would indeed look outstanding on my site. But alas...money IS a factor.
I still have to stop and check the ready mix plant...but I suspect I'll end up with plain old grey concrete with a broom finish. Maybe sometime in the future it will be a wonderful base for some nice stone.
A friend of mine is doing a walk right now with some type of dye that he just squirts on the top as he floats it out. The first sections he's finished look pretty good. Kind of a slightly curved pattern to the color (from being drug out by the float). He said it's pretty inexpensive. I think he got it at HD.
Good luck with your project!Any jackass can kick down a barn, but it takes a carpenter to build one.
Pirgerbruce
You mentioned that the stamped concrete would be to expensive, maybe just do a boarder, certainly a lot cheaper and still get something other than grey concrete.
I see drive ways done this way all the time and I cant believe it adds all that much.
JMO
Doug
In order to get a good exposed Ag job. just get an expert. And check his work first. Exposed Ag is harder to do properly than ordinary concreting.
With respect to some advice that has been mooted here.
Do not float. Floating brings up the fines. You do not want to bring up the fines. All you want is the ag sitting on top. The more you float the more fines the more yopu have to remove to get to the ag.
The trick for exposed is all in the screeding. Start playing with the screed and bring up the fines and you're in more strife than Flash Gordon.
regards
Mark
http://www.quittintime.com
perhaps adding some color to the concrete would be a good compromise - lot easier to finish than exposed - but more pleasing to the eye than plain concrete
Just a thought,
Shoe
In our world we see it (ex-ag) every day. Hurts to kneel on, hard to keep clean, hard to caulk expansion joints in an even manner that sheds water, hard on bare feet...but looks nice, esp. when new, and is fairly non skid.