hey fellas.I 've got a good one for you.We do a good amount of hardscaping here in s.e. Pennsylvania and I've seen alot of guys use screenings (stone cinders) instead of concrete sand.OK my question is why?We primarily use E.P. Henry and they really push sand.Am i missing some benefit to the screenings?Thanks for your help.
concrete sand or screenings?
cody
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hey fellas.I 've got a good one for you.We do a good amount of hardscaping here in s.e. Pennsylvania and I've seen alot of guys use screenings (stone cinders) instead of concrete sand.OK my question is why?We primarily use E.P. Henry and they really push sand.Am i missing some benefit to the screenings?Thanks for your help.
Somebody is going to have to explain hard to convince me how stone particles break down faster than sand particles. Sounds like hokum to me.
I've used both and love stone dust. My observation is a more stabil base eslily compacted and worked. The larger angular particles tend to fit together well and the sand particles tend to roll around. Just walk on the two while your working and see the difference under foot.
We also went against convention and used less base than many for walks and patios. A 3" layer of stone dust over top landscape fabric did it for us. NO problems. The fabric is essential as it keeps fine soil below from co-mingling with the larger base over a period of time.
I've used both and love stone dust. My observation is a more stabil base eslily compacted and worked. The larger angular particles tend to fit together well and the sand particles tend to roll around. Just walk on the two while your working and see the difference under foot.
We also went against convention and used less base than many for walks and patios. A 3" layer of stone dust over top landscape fabric did it for us. NO problems. The fabric is essential as it keeps fine soil below from co-mingling with the larger base over a period of time.
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Run a search for the thread 'patio base'...it says it all.
I'd say more, but my brain is mush and my eyeballs have given out on me - website updating bonanza....
I'd say more, but my brain is mush and my eyeballs have given out on me - website updating bonanza....
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Sound to me like a lot of you guys in the SE Penn area/ South Jersey area would benefit from attending the EP HENRY MidAtlantic Hardscaping Trade Shows Feb 13-19 at the South Jersey Expo Center in Pennsauken. See what these guys have to say and get ICPI Certified!!
BTW, even though I do not get into paver installation, I believe it goes Fabric, modified stone (quarry blend) added in 2" lifts and compacted (this is the most essential step as the base must be stable and the ground can't "pump"), then not more than 1" of sand 3/4" recommended, followed by the concrete paver.
Again , I'm no expert, but you can go to www.ephenry.com and see what they have to say, or register fr their show!!
Bob
BTW, even though I do not get into paver installation, I believe it goes Fabric, modified stone (quarry blend) added in 2" lifts and compacted (this is the most essential step as the base must be stable and the ground can't "pump"), then not more than 1" of sand 3/4" recommended, followed by the concrete paver.
Again , I'm no expert, but you can go to www.ephenry.com and see what they have to say, or register fr their show!!
Bob
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Only benefit to screenings is less ingredents in the recipe. The sand is used as a bedding layer. The purpose is to keep the pavers from shifing side-to-side. When you compact the pavers into this bedding layer you should be accomplising 2 things. The first is setting the pavers into the bedding layer. When I say into I mean they must make an indent into the material. The next task which should be accomplised is the bedding material forced up in between the pavers. When laying a tight pattern, a 90 degree herringbone, the screenings are to large to push up through the pavers. The bedding layer should allow water to effectively and effeciently drain through. Sand meets this criteria. Screenings do not.
We repair about 2 projects a year orginaly installed by other contractors. They always have screenings under them. We remove the screenings, which by the way is like concrete to remove. Then use concrete sand. I find inexperianced installers using screenings because they are trying to save labor and materials.
Also, always a must to use filter fabric under your base.
Rex
We repair about 2 projects a year orginaly installed by other contractors. They always have screenings under them. We remove the screenings, which by the way is like concrete to remove. Then use concrete sand. I find inexperianced installers using screenings because they are trying to save labor and materials.
Also, always a must to use filter fabric under your base.
Rex
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Well I know this has been debated in depth before but I didn't pipe in on that thread. I'll take this opportunity to add my two cents.
Bedding sand should be sharp and have symetrical particles not flat or elongated. Flat particles (found in most limestone screenings) do not compact completely and will settle unevenly over time.
Locally, limestone screenings have a lot of very fine particles (passing the no. 200 screen test). Very fine particles cause an aggregate to hold water. Water lubricates the aggregate and causes rutting and uneven settlement.
Limestone is very soft and makes for great landscape boulders. This is because it is weathered so easily with time and water. Limestone dissolves in water. It doesn't just erode it actually dissolves. The sand we have locally is much harder than limestone and therefore more suitable for constructing pavement bases. Softer materials may pulverize into finer particles under load and cause water retention. A quick test for hardness: if the larger sand particles cannot be scratched or brocken with a pocket knife then the sand is generally hard enough for pavement bases.
A suitable bedding sand will be a coarse multi-grained sand with 0% ( or very close to zero) passing the No. 200 sieve. The fines are the most important factor in choosing a bedding sand. Bedding sand should conforn to ASTM C33- gradation for bedding sand OR CSA standard A231.1. Any quarry will be able to provide you with a current sieve analysis to compare to the standard.
In case you are interested the standard for base material is ASTM C2940. This standard allows up to 8% passing No 200 sieve.
Note: water will not pass through a NO. 200 sieve.
Bedding sand should be sharp and have symetrical particles not flat or elongated. Flat particles (found in most limestone screenings) do not compact completely and will settle unevenly over time.
Locally, limestone screenings have a lot of very fine particles (passing the no. 200 screen test). Very fine particles cause an aggregate to hold water. Water lubricates the aggregate and causes rutting and uneven settlement.
Limestone is very soft and makes for great landscape boulders. This is because it is weathered so easily with time and water. Limestone dissolves in water. It doesn't just erode it actually dissolves. The sand we have locally is much harder than limestone and therefore more suitable for constructing pavement bases. Softer materials may pulverize into finer particles under load and cause water retention. A quick test for hardness: if the larger sand particles cannot be scratched or brocken with a pocket knife then the sand is generally hard enough for pavement bases.
A suitable bedding sand will be a coarse multi-grained sand with 0% ( or very close to zero) passing the No. 200 sieve. The fines are the most important factor in choosing a bedding sand. Bedding sand should conforn to ASTM C33- gradation for bedding sand OR CSA standard A231.1. Any quarry will be able to provide you with a current sieve analysis to compare to the standard.
In case you are interested the standard for base material is ASTM C2940. This standard allows up to 8% passing No 200 sieve.
Note: water will not pass through a NO. 200 sieve.
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Geotextile fabric may be used in areas where soils are saturated. While not necessary in all applications, it can delay deformation of the base from loads. Fabric is particularily useful over fine soils such as clays and silts. They prevent soil from being pressed into the aggregate base, espcially when saturated.
Thanks for all the great feedback.Myself and all my foreman are ICPI certified.Its the only way to go and its a great selling point.
It also sets you apart from the "hacks" out there.As far as MAHTS
and all its offerings ,one word,invaluable.I have never used cinders but i do see quite a few that do thats why i asked.Both
E.P. henry and ICPI stress sand and who are we to argue.Its also a good selling point to customers when you show them the installation guide in the E.P. henry book and you can explain to them why this is and that this is the way your company does it
Charles Vander Kooi is awesome! The man knows what he is talking about
It also sets you apart from the "hacks" out there.As far as MAHTS
and all its offerings ,one word,invaluable.I have never used cinders but i do see quite a few that do thats why i asked.Both
E.P. henry and ICPI stress sand and who are we to argue.Its also a good selling point to customers when you show them the installation guide in the E.P. henry book and you can explain to them why this is and that this is the way your company does it
Charles Vander Kooi is awesome! The man knows what he is talking about
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Well, my eyes are still a bit fried from working on the PC, but I will say my method is in fact slower that using sand. We go through the same compaction of lifts of stone as someone using sand would, up to the point the pipe are set and the sand is screeded. At that point the sand user starts laying.
At that same point our screeding work has just begun. We will screed and re-compact 3-5 more times.
And I think the screening size question has merit - we've used screenings with a high particulate content and the largest stone no more than 1/4", and we've used stuff lower on the particle content, with slightly larger stones (largest being up to 3/8"), and have had better long-term success.
The question I still have is, if limestone does such a poor job of maintaining itself structurally, why is it used as a base material at all? Sure, in 3/4- the stones are bigger, and one would guess it'd take longer to erode or dissolve. But it would still happen.
I'm betting it's the price that makes it an attractive choice for most pavements. I can get it for $1.50/ton at some suppliers, though the stuff we use is $6/ton.
I'm gonna save some of my debate points for a future thread.....
At that same point our screeding work has just begun. We will screed and re-compact 3-5 more times.
And I think the screening size question has merit - we've used screenings with a high particulate content and the largest stone no more than 1/4", and we've used stuff lower on the particle content, with slightly larger stones (largest being up to 3/8"), and have had better long-term success.
The question I still have is, if limestone does such a poor job of maintaining itself structurally, why is it used as a base material at all? Sure, in 3/4- the stones are bigger, and one would guess it'd take longer to erode or dissolve. But it would still happen.
I'm betting it's the price that makes it an attractive choice for most pavements. I can get it for $1.50/ton at some suppliers, though the stuff we use is $6/ton.
I'm gonna save some of my debate points for a future thread.....
Different areas have different types of stone dust! Some stone dust is made to be like concrete sand. (I just came from out West where they don't have the right kind of sand but the the stone dust is manufactored to concrete sand specs. Limestone screening /stone dust is not the same as concrete sand. Using Limestone screenings goes againts all manufactrs installation specs. While you might get away with it some day it will bite you in the private parts
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