View Full Version : suitable fill for pavers
03-11-2001, 12:17 AM
Hi everybody, I have been lurking on this site for a couple of months, listening to the many voices of experience here.
I recently moved my business from a booming city in Alberta to a not so booming city in British Columbia (hello fellow canucks). I picked up a fairly large (for me) paving stone job and was just informed that rather than put the patio at ground level, the customer would prefer to have the patio at the same level as his pool, approximately 3 feet above existing grade. So I am planning to build a retaining wall of 3X6 cedar on three sides of the patio area (800 square feet) and don't know what to use as a base to fill in the first 2-2.5 feet. The guy at the quarry suggested sand, but I am not convinced. If anybody has built anything similar I would appreciate your advice.
p.s South Vancouver Island has very litte concern about frost. Thanks in advance
03-11-2001, 01:44 AM
First, I would suggest something stronger and longer lasting than 3x6 wood for the wall. In our area, walls must be 6x6 pressure treated timbers. However, a segmental unit retaining wall would last longer and create fewer headaches over all. You could then fill with compacted lifts of crusher run gravel.
03-11-2001, 04:38 AM
Definetly use something stronger for the walls as she mentioned, i.e. retaining wall block. You wouldn't want to have to replace those timbers after they rot away (especially being next to a pool would probobly speed that process up!). I'd imagine if you did have to replace them that it would ruin your paved area also.
Now for the fill. I don't believe someone from a quarry told you to use sand???????? :( Thats definetly not a suitable base course, and its especially not good fill material at all. I'd use gravel or a base course material to fill in and get your height and than start as you usually would from there.
Try to compact your base material in 6"-8" lifts when you fill it. It will make for a much better compaction so you won't have much settling later on down the road.
Hope this helps!!
(Damn it feels good to be back! HI EVERYBODY!!)
Don't be so quick on what a quarry will tell someone. Have had them tell customers the same thing here. Also had them tell them to use pea gravel for base. I think your fill should be 3/4 t0 1" clean chips with no fines. You're looking for drainage here not just fill.If you have to do wood look into some of the new composite products and definitely 6x6's. Segmented concrete can't be beat.
03-11-2001, 10:36 AM
I know exactly what your saying. It might have came out the wrong way. I was just shocked the quarry said that. It probobly sounded like I meant I didn't believe sadmac. Some people rather save face and spit out an answer to someone they think doesn't know any better than tell them they don't know.
Anyway, sorry about the confusion, and yes, there are many stupid "experts" out there! ;)
Not a problem. Most of these guys look at it as just "fill" and don't realize the structural or drainage aspects. Good to see ya' back in the forum. Been out on bivwac?
03-11-2001, 10:51 AM
Thanks for the info, The 3X6 cedar will be laid flat, 6" side down, much less than half the price for 3X6 as compared to 6X6. I agree that modular block systems are stronger but the aesthetics of the place require wood. Guido, The quarry guy did highly recommend sand and because I haven't worked in this area before (lots of rain, no real winter) I figured he should know what he is talking about. That said, is there any reason I couldn't use blast rock for the first foot and a half and then cover with road crush before I put the screeenings on. That is how we used to build driveways in Northern Ontario.
03-11-2001, 11:07 AM
If Blast stone is what I'm thinking of (what I call ballast rock) it would be okay too. Your basically looking for something that will let water drain down through and keep stable. Those are both very important factors here. Let us know what happens!
Guess I am going to be diferent here:)
for a 3 foot fill I would use 3 inch stone as my base course up til the last foot or so, 3 inch stone drains well and does not move as much as smaller stone. After the 3 inch stone I would put down a layer of fabric and then use 3/4 inch minus stone for my base for the pavers.
I would use something other than wood for my wall, a large size retaining wall block like Vers-lok or Pisa II would be a better choice. Are you building it around an above ground pool? post more and we can put our heads together.
03-11-2001, 11:49 AM
The pool is in ground but the site is sloping (10" over 10 feet), presently the pool is skirted with cement (about 6') and outside of that are planting beds with really old style stackable walls. We are removing these planting beds to make the patio as wide as possible but these retainers are used throughout the property. I don't think adding a different style of stone retainer would look good in this setting. Also we are building a an arbor out of cedar to cover the new patio. The patio will be 65 feet long and 12 feet wide with the arbour posts inset one foot on each side and spaced 8 feet apart, we are also going to install some inground planters to break up a possible landing strip effect. Hope you can get a better mental picture with the added info.
Paul, kind of fabric are you referring to?
Guido, I think we are on the same page, Blast rock here is basically rock they blast out when they build a hiway, jagged edges irregular size, also be called rip-rap in other places I've worked.
Looking forward to more input,
See if you can get a color close to the existing block, the higher walls will match if the color is close due to the change of scale.
Fabric I would use here is a woven fabric with a high puncture strength. it will allow water to drain thru and keep the fines from migrating thru the 3 inch stone.
03-12-2001, 07:21 PM
I am going to jump on the concrete block band wagon on this issue. If you are looking for the "old world" feel on the project maybe look into the tumbled prooducts. I know that Versa-lok takes their standard units and tumbles them to give a weathered look. Keystone is coming out with a product this year that is very similar. Both products use their pins to create a wall that is not only visually pleasing but structurally sound.
As for the backfill, I would use a 3/4" clear stone up until the last 12". Then lay the fabric and cover with soil. Base material that we use is a 3/4" to dust limestone. Compacted in 6" lifts it creates a good base.
03-12-2001, 07:51 PM
Should the 3 inch stone you referred to as fill also be compacted? Does it compact since there are no fines?
Ed, We compact everything :)
All fill should be compacted. I like 3" stone because it has greater shear factor once set in place the larger faces of the stone resist movement.
03-15-2001, 12:41 AM
Thanks for the input everybody,
I feel bad saying that after all that help we decided to go with a raised cedar deck
03-15-2001, 07:45 PM
Even though sandmac is going with a cedar deck i still feel i should add to this topic. The quarry person was right! Sand is one of the best fill materials available for a couple of reasons. 1. Its cheap. 2. It compacts better than just about anything. How can you expect to achieve a good compaction rate with 3" stone? The last 6" i would place class 5 (road base) and compact that. As for drainage, You dont need a fill material that drains well on a paver patio. The patio should have a grade on it that directs water to a drainage system or other area where water runs to. There is no reason to use fabric unless the ground u are working with is very unstable its a waste of money. I would like to hear from anyone who thinks with different opinions.
3" stone is compactable, used for road base or where there is a large fill to be made. Reasons- the shear factors larger face of the stone mean it will move less, ask anyone that has had to shovel it, not easy, shovel just about bounces off :)
Sand will compact but sand also moves too easy the finer particles will allow it to move very easy for the same reason it compact so well it moves.
Frost movement on fill I could fill volumes on this one, I want a sub-base that won't hold water 3" stone does this.
Fabric is used on 3" stone is to stop mitigation of the small gravel thru the larger gaps.
Cost here 3" stone is cheaper than sand I pay $4.95 per ton for 3" Vs $6.83 for sand. Plus volume, a ton of 3" stone will go alot farther on a fill than a ton of sand, so if cost was not a factor you will use much more sand than 3" stone.
If you need more info on this just let me know.
03-15-2001, 10:04 PM
Civil engineering dictates that when you are making a base or bed of any kind, the big stuff goes on the bottom. The little stuff goes on the top.
And I'm not a big proponent of sand anyway. I'm told by smart people here that the sand they use is angular enough that the 1" they use doesn't shift and move under the weight of traffic. I'm not convinced, but I'll go along with an inch for the sake of arguement here. But sand is essentially uncompactible. Like water. If your sand is dry, when you lay it in it is as dense as it will ever be. You can drive vibratory rollers used on highways and it will never be any more dense then it was when you first put it in.
I think Guido said he plays a game with new recruits, something about compacting sand until you can't see your footprints in it. The joke is, it never happens. It will always shift.
3'? It'd be like compacting 3' of those balls in the play areas at fast food places. Or marbles. Wherever there was foot traffic, you'd end up with depressions in the pavement.
03-16-2001, 10:06 PM
Id like to see anyone compact 3" material for use on a residential project. As for price i can see wher we differ. In MN sand costs $2-3 per ton wear as any thing of 3" is going to cost at least $30 per ton. Maybe things are done diferent in other states. Around here i have never seen a state highway project using anything greater than 1.5 inch material. I would like to hear from anyone who has used 3" stone for fill material on a project. Sand is basicly compacted from the time you put it down because there are no voids to fill. I am really eager to hear other comments on this issue
Sorry can't give you one where we have done a residential project, we don't do them, as for a project where we have used 3" just check our web page. the river walk in West Dundee was one where 3" was used. Not many residential projects need that much fill. Compaction of 3" is really easy do to the larger surfaces of the stone, settlement of the stone is fast most times with just a standard plate compactor, but we use a front mounted roller on our skid steers. They are faster and give a better surface for setting pavers. Sand still has the ability to move even after being in place, if it was such a good material it would be used for the base material but we all know that it will move given time.
03-17-2001, 09:56 AM
Never seen a roadway with 3" stone? Over the past two years I've seen sections of highway go up in my area using stone and broken concrete in sizes in excess of 2'!! Got smaller as you went up.
I'm seeing lots of posts about what's cheap. Not a lot of posts about what's good.
Lawnking - please read over my earlier post. Or go for a walk on the beach. Notice how your feet sink in and the sand squishes around? Same deal with this application, but a little slower because of the brick on top. Marbles would also automatically compact to their maximum density. That doesn't make it a good choice.
Big stuff on bottom, little stuff on top.
03-17-2001, 01:10 PM
I agree with Paul and Stonehenge. Biggie size on the bottom and the smaller stuff on the top. We use the bigger stuff for raised patios and driveway bases. In driveways the bigg stuff gives you better containment of lateral movement. Have never had a failure. Check with the ICPI or any qualified paver manufacturer. They will tell you sand as fill is "EVIL".
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