Good day all !
Well this summer’s project is the backyard landscaping.
According to my girlfriend, it would be nice if it was done this year (which mean : finish it up this summer and/or asap). haha
I am planning interlock paver with concrete border/edging.
I have already excavated +/- 12″ of soil and clay were the interlock will go.
QUESTION 1 :
0 – 3/4″ is crushed stone which size is from fine powder up to 3/4″.
3/4 clean is crushed stone that is 3/4″ only clean.
Now, does both 0-3/4 and 3/4 clean as the same “drainage” qualities?
i.e. If I use clean gravel will it “drain more” and prevent freeze-thaw problems than if I used only 0-3/4″ crushed stone ?
0-3/4″ create a more “sturdy” foundation but does it drain as much ?
Which one would be better ?
QUESTION 2 :
How deep needs to be the concrete edging / border ?
This will be poured using regular concrete ?
Thanks in advance,
Ben
Replies
3/4 clean drains better because the fines don't fill up the voids between bigger pieces. 0-3/4 is basically gravel, which packs well and makes a good driveway base but doesn't drain well.
Any aggregate that has particles of the same size will drain well. Usually pavers are set on sand, not stone; sand is easier to work with and still drains well, and you can dust sand over the surface of the pavers to fill in the gaps. If you try to do that with a stone base the sand will just run through and fill the voids in the crushed stone.
As for question 2, I wouldn't do a poured concrete border, I would just set a soldier course of some sort or a metal edging. If you really want a curbstone though, ideally you would go below the frostline but that's not practical so just go deep enough to keep them from falling over, and accept the fact that frost will move them around a bit and probably crack them over time. 12" is enough for that.
0-3/4 (which is often called 3/4-minus) will not drain as well as all 3/4 (called 3/4-open). In spite of that, I would use the 3/4-minus. That's the industry standard. The amount of water minus can hold is significantly less than what open can hold. Surrounded by soil that will try to drain into the gravel field, your open gravel can become a little reservoir that freezes and heaves. Use the 3/4 minus and compact it well with a plate compactor, then screed an inch of sand over the top to create the base for your pavers. I wouldn't pour concrete for the edge unless you have to; there are a number of good edge restraint materials on the market now. My own preference is Snap-Edge, an L-shaped plastic product that you spike in plkace and which can be bent to conform to almost any curve. If you do pour, 4" wide would be the minimum.
Marty
"The plants have been good to us." Lester Hawkins
It might not be preferable, but I've got a patio with 1' x 1' pavers on 4"- 6" of #2 gravel. If you decide on gravel, put some weed block fabric down first, then make sure the gravel's compacted well on top of it.
My patio's about 12' x 15', and has been in place for the last 7-8 years. No movement or heaving. We set the kids' wading pool on it and dump the water over it afterwards, and it all drains immediately.
For a patio you want the 3/4 minus. You'll never get your base flat with clean gravel and the sand will wash through.
12" excavation is good. Add the base in two lifts and compact after each one.
I believe Unilock says to add sand to a level above the bottom of the pavers and plate compact them down to finished grade. This forces the sand up in between the pavers and locks them together.
They have some info on their website.
http://www.unilock.com/downloads/technicalResources/Install-Specs-Interlocking-Pavements.pdf
The patio should be pitched away from your home. That will take care of any drainage issues.
Thank you all for the answer.I guess my best bet is to use 0-3/4 and a sand layer on top.Some people also suggested a 1" thick of small diameter crushed stone on top instead of the sand. Apparently better to keep ants away. (?)I think I'll forget my idea of a poured concrete border, I thought they look good, but 98% of people says that their previous experience with that was not good (cracking, moving etc...)As for drainage, the land is drained toward the front of the house.
(the backyard end point is higher than the front of the house at the street) I was thinking of putting a french drain and 4" perforated pipe from the patio edge, up to the front of the house near the street, would it work considering there is like 65ft between backyard and interlock patio ?I think elevation difference is 3ft.Thanks again for your help
Ben
My yard is similar and I used a couple of these as basins to collect the run off.
http://www.doityourself.com/invt/u149347
With a grate on top and connected to unperforated corrugated pipe and out to the front of the house. Picked up the gutters along the way.
If you can dig farther out and create a swale in your lawn as a lower area than the patio it would help. I know, easy for me to say. Mine are in some landscaping.
If you can get the smaller crushed stone it is a better product than sand. If you go with sand, make it the coarsest sand you can get - the really fine stuff is too soft, even when compacted. While mason's sand will work for sweeping in the joints, you would be WAY better off if you can find a local supplier of poly-sand. It's a bag product, and it's spendy, but it eliminates the ant issue, it eliminates the weed issue completely, and it doesn't ever wash out. Basically, what you get is sand with a polymeric resin added, You sweep it in and compact it just like regular sand, then you wet it down; the sand sets up like mortar.Marty
"The plants have been good to us." Lester Hawkins
poly-sand...
Interesting... do they sell that at any of "the regular places"?. I have often mixed a weak mix of Portland and sand (for stone screenings) for a dry placed material that gets hard. That doesn't work for on top of brick pavers though because the Portland messes up the appearance of the brick.
Thanks again for all of your answers very valuable info.-Gutter & 4" pvc
I did connect my main house gutter to the 4" pvc going to the street.
One thing I have noticed there is a lots of "roof shingles sand" which might be a problem in 10 or so years (clogging the drain).
Maybe periodically clean the elbow going to the 4" would be a good idea (?) Any other solution as per filter ?-Catch basin
Catch basin might be interesting at problematic area on the landscape.
I will consider that very much.I live in Canada, where it gets to -22oF during winter.
For sure the drains will freeze during winter and open up again in spring time. My concern is more of how much the drain (if it ever filled with water) will expand and deform the surrounding area.i.e. If I have a 4" non perforated drain crossing a interlock sidewalk at 6" under the paver - will it move the paver above if theres water in it and it freezes or the crushed stone will absorb the change in the drain volume ?Thanks again!
Ben
To be honest, I don't know. I get it from a local landscape supply outfit or the paver yard at a fair discount, so I've never bothered to check for it at the big box stores.Marty
"The plants have been good to us." Lester Hawkins
This article might be helpful:
http://www.masonryconstruction.com/industry-news.asp?sectionID=0&articleID=245268
If you are that concerned about drainage you can layer your stone types using geotextile fabric (heavy landscaping fabric) between the different types of stone. You wee this in road building all the time. So, you could put down 6" of the drain rock and then 5" of 3/4" minus (as you call it) with the fabric in between. Personally I'd then top off with 1" of screenings - or fines - or whatever they call it where you live. It's basically like coarse sand produced from crushed stone mixed with the very fine stuff. Levels out easily with a screed, and packs down really good - especially with a vibratory plate compactor. You can rent one of these. You still need the mason's sand to spread over the top of the completed pavers - then run the plate compactor over it again. This will lock the pavers down tight.
BTW - the naming of stone products is highly regional - a lot of this is controlled by the state DOT - I guess it is the same with the providences, but don't really know. This is because the DOT is one of the main customers of a quarry, plus all stone used in road building has to be graded to DOT standards. For example, attached is a document that shows the stone products as we know them here in NC.