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October 2, 2008
Patio - Cement or not?
We are going to have a bluestone patio installed in our backyard. Our contractor recommends laying the bluestones in a concrete bed. After installation the concrete will only be visible in the small spaces between the bluestones. His reasoning is that the concrete bed will help the rain water drain properly into the drain he's installing, and keep the bluestones secure so they don't move or raise up or crack over time.
I'm considering having the bluestones installed without using a concrete bed. That seems more organic to me. If you have a bluestone patio, how was it installed? What’s your experience been? Any pros or cons to either process? And if the bluestones are not put in a concrete bed, what would they be put on? Just dirt, or gravel, or…?
Thanks.
Comments
If you don't want to use concrete, the bluestone can be set on top of gravel- sand - traprock dust. you will have to dig down 8" to get a good base layer, and then the bluestone is set on top of this.
if drainage is an issue, you may be able to put in perforated pipe in the gravel layer to ties to a drain.
the plus of concrete is you can pitch the patio away from the building and into a drain.
thx, eric. handymaneric.com
Posted by: HandymanEric at October 2, 2008 12:30 PM
Bluestone can be set in Sand or Cement. Sand is cheaper and stones can be replaced easily if damaged. If you have good earthly drainage, sand is fine. I dont recommend a concrete base. Over time, the concrete may crack and along with it, the bluestone will crack. If the area has bad drainage, then concrete is the way to go. The stone would be set to allow for the proper water run off.
If you have any questions... Contact Don at PERRONE Maintenance & Construction - 1-800-761-7847
Posted by: Perrone at October 2, 2008 12:31 PM
I think I'll start a blog that says "Permeability Rocks!"
Why use concrete and then put in a drainpipe to our overloaded sewers? If you let it drain naturally through sand, you won't need a pipe at all. Our 180sq ft flagstone were laid over 4-6" sand several years ago and have had no water problems at all.
Posted by: cmu at October 2, 2008 12:58 PM
The houses in my row have original bluestone patios (118 yrs old) off the back of them. *Most* of them are very cracked the reason being tree roots.
I'm sure when these were laid the trees weren't mature but since the stones have really taken a beating. I'm not sure if you have any trees around but the root will lift the stones right up as they grow. Concrete might help prevent it. Not sure.
Posted by: TownhouseLady at October 2, 2008 2:12 PM
Concrete will NOT help prevent tree roots from lifting/cracking concrete -- just look at old street trees and the concrete around them!
Posted by: SenatorStreet at October 2, 2008 3:20 PM
I've been thinking about the same issue. Another factor I need to consider is the pitch of my property. I am assuming you need to grade first, then lay down sand and then lay down bluestone or pavers etc?
Posted by: Boerum Hill at October 2, 2008 4:25 PM
Um, reno blog anyone? Some folks are in the process of this right now...
Posted by: Action Jackson at October 2, 2008 4:35 PM
If the bluestone is set in sand, the patio can still be graded to a drain or away from the building. As mentioned earlier, setting in sand is a much greener solution because it lessons the rainwater load on our sewer system. It also allows the water to soak into the ground and nourish surrounding trees and plantings. Concrete will not prevent tree root damage and if there is damage in the future, it will be much easier to fix if the stones are set in sand.
Posted by: JoeBushwick at October 2, 2008 5:59 PM
I agree w/ JoeBushwick. If drainage is a problem, I'd go lower than 8 inches & put in a few layers of pea grit under the sand. I also put landscape fabric under the pea grit for mine. A neighbor w/ worse drainage put a perforated pipe under the pea grit because she has a lot of clay. Even a very slight pitch away from the house goes a long way towards keeping the basement dry.
Posted by: Arkady at October 3, 2008 9:23 AM
My folks have had a bluestone patio on a sand and stone dust bed that has held up perfectly since the early 80s. It looks and wears far better than concrete. It's also much more amenable to a DIY approach if you're interested.
Posted by: jb312 at October 3, 2008 9:42 AM
to clarify my answer and address " cmu "
"Why use concrete and then put in a drainpipe to our overloaded sewers?"
not all drains are attached to the sewer main, i try and drain water to the back of a bldg lot, ideally to an area used as a garden.
" If you let it drain naturally through sand, you won't need a pipe at all. "
each project is unique, if the bldg is already getting water in the basement from the backyard during heavy rains { not an unusual thing in Park Slope } you need to remedy that when installing a patio. There are some great comments above on how one can go about doing this.
Lucky you that your patio works and your basement is dry, enjoy your latte.
Posted by: HandymanEric at October 3, 2008 10:20 PM
My landscaping company has done quite a few stone patio installations in Brooklyn and we always do sand.
In Brooklyn the ground goes through several freeze/thaw cycles every winter. When concrete freezes is expands, when it thaws it contracts. This will cause the stones to crack. With sand this is not an issue.
If you go with a sand bed make sure you do a good job of grading and compacting the soil before you lay your rock. It will make a big difference in the final product.
And in answer to BoerumHill's question yes, you need to grade before you lay down your rock. Ideally your yard should be graded to slope away from your house whether you have a patio or not.
Posted by: nebrait at October 5, 2008 7:25 AM
HandymanEric makes a good point when he says every project is unique.
I'm a big fan of the French Drain. It's such a simple, low tech solution and in many situations works as well or better than more complicated, more expensive solutions.
Posted by: nebrait at October 5, 2008 7:36 AM
We laid our stone in a mix of quik-crete and sand. After laying, we then soaked the entire thing to set it. Haven't had a problem with drainage in 5 years.
Posted by: crowlish at October 6, 2008 8:18 AM
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