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Paver Advice needed

Discussion in 'Landscape Architecture and Design' started by fall46, May 12, 2004.

  1. fall46

    fall46 LawnSite Member
    Messages: 141

    Iam a homeowner so bear with me I can imagine the nodding of heads when reading this one!

    Allright,, I have some questions about work that was done in excavating for pavers. When he dug it out using a bobcat I helped him take some quick measurements but we did not use pull string to verify the slope was correct of the subase. We were also trying to beat a huge storm so we kind of scrambled to load in the base material. 1) Concern do you need to use pull string to verify subsoil slopes correctly (it appeared to slope correctly but I know looks are deceiving) or is the sloping emphasis primarily when adding base material (class5) or is it a must for both. I know u cant or shouldn't adjust slope using your screeded sand........but what about doing so using the base material?

    #2 We didn’t compact subsoil with tamper (tried to beat the rain) One specific area of concern is where the downspout would exit .................the surrounding ground would "pump" when walking on it. Although 2 days earlier we had 1.5 of rain. Obviously this contributed to that problem. So after scrambling to put in the base material and getting a fair amount in ...it rained almost an inch's worth in an hour. Alot of the base material was almost quick sand where it was low (low because we didn’t get a chance to grade it fully as by this time it was raining like hell)
    Dried up later in the day but areas where it was low were extremely mushy when walking on and had puddles. We still need to verify and confirm slope of base material but want to wait until all areas are dry? 2-3 days is that enough time?

    How big of a hole have I dug for myself here what should I do...... surely it has rained when people were installing the base?

    Assuming I already dropped the ball on sloping the subase or @ least verifying it with pull string can I correct or enhance the slope by adding more base material (class 5) to achieve a proper slope?

    How serious is it that the subase wasn't compacted before adding base material . This a patio not a driveway if that is any consolation?

    Any help/ advice would be appreciated?
  2. Rex Mann

    Rex Mann LawnSite Senior Member
    Messages: 621

    My company only installs pavers and retaining walls. We install per the ICPI, Interlocking Concrete Pavement Institute, guidelines, which are the accepted standards for the paving stone installation industry.

    The sub-soil should be the same pitch as the final elevation. It can have a tolerance of + or - 1/2 inch over 10 feet. The aggregate base material can have a + or - 3/8 inch over 10 feet. Sticking to these tolerances will help ensure an even thickness of bedding sand.

    Tamping the sub-soil with a tamper is part of an ideal installation. However, only a large walk-behind compactor will actually do any good on clay soil. a rammer is the preferred machine for clay soils.

    Downspouts need to be re-routed to keep the flow off the pavers and nearby areas to prevent undermining of the aggregate and sand.

    Pumping is not a good thing.......I am sure you have realized this.

    Let the aggregate dry out until you can walk on it without sinking down. Also, if you tamp it and water is coming to the surface it is still to wet.

    If you do not want to wait for it to dry or you can not wait then you can add one 94 pound bag of portland cement to each ton of aggregate base. Pour the portland over the aggregate and rake it in as deep as you can, then tamp. The portland will "SUCK-UP" some of the moisture, but will stiffen up your base.

    I hope you used a geo-textile under the aggregate. If you failed to, the result will be migration of the aggregate into the sub-soil during the Spring thaw over time.


    Try the above link for more information.

    Your setbacks are just simple obstacles, which can be overcome for a successful installation.

    Best of luck


    Rex Mann

    our web site :)
  3. fall46

    fall46 LawnSite Member
    Messages: 141

    I appreciate the response and I did read the ICPI recommendations regarding geotextile,,,,,,, although after talking to the landscape supply store and some other stores most see it being used on driveway applications where your receiving alot of weight......don’t get me wrong it makes sense, but what I most interested in is....... without verifying the subsoil slope ........if I can achieve the right slope with the base material can I get by?

    keep in mind

    - I didn’t use geotetxtile

    - I didn’t tamp subsoil

    - I didn’t compact in 2-3 inch increments

    Whats should i do?

    - Obviously wait until its completely dry

    - tamp until my arms fall off! ( go over and over maybe 10 -12 passes?

    - start over meaning I would have to get rid of all of the base material or we could maybe salvage it by placing it in a pile? recheck the grade..and then replace back in (would it be to contimnated at this point) What are people paying for the geotextile they quoted like 300.00 i think for a 6X100 foot role? Outrageously expensive........what brand should i use my total sqft is 330 how much would I spend for geotextile (roughly)

    Can I still make this thing work?
  4. Rex Mann

    Rex Mann LawnSite Senior Member
    Messages: 621

    I pay 6 cents a square foot for the geo-textile woven. Many people confuse geo-textile with geo-grid. Geo-grid, used primarily in building retaining wall is around $1.00-1.50 a sf. Maybe they were confusing the two. You can most likely buy it at a company that sells pavers. They sell it for around 20-25 cents a sf.

    To do it right...............Take out the aggregate, at least most of it in a pile. Then re-excavate to the correct slope. Install the geo-tex and compact in 2-4 inch lifts, depending on the size of your mechanical plate compactor. and, you know the rest from there.


    Rex Mann

    our web site
  5. Ice_Gargoylle

    Ice_Gargoylle LawnSite Member
    from indiana
    Messages: 60

    compact it til your arms fall off.
  6. fall46

    fall46 LawnSite Member
    Messages: 141

    so u defintely think i should try to dig out the aggregate to verify the slope.... Before u add the aggregate do check u for correct slope then ....................or acheive slope after the aggregate has been placed
  7. Rex Mann

    Rex Mann LawnSite Senior Member
    Messages: 621

    Make the slope accurate in the subsoil if you are going to remove the aggregate. If you are not removing the aggregate, use it to correct your slope.


    Rex Mann

    our web site
  8. hole in one lco

    hole in one lco LawnSite Bronze Member
    Messages: 1,793

    90% of a patio is the base if your base sucks so will the patio.
    Yes you need the felt under the base.

    My question to you is do you want to spend all that money and end up with roller coaster patio or a nice flat patio?

    Take your time and do it right .
  9. fall46

    fall46 LawnSite Member
    Messages: 141

    Ok so to error on the side of caution I will dig it out and lay the geotextile.......... whats the brand name to get.,...the places that I have called say that Mirafi 500x is what they sell,,,,,,,,,,however they only sell it in 17.5 X 300 rolls and costs 300.00+ for that much obviously I dont need that much.........but I do need landscape fabric for some mulch beds where some prymadial abrovitee (sp) and some other shrubs/bushes will be.... Can I use the geotextile as a landscape fabric or will it not let enough water through,,,,,,,,,

    What brand names are people using or should I ask for????????????????,,,,,,,,,,,does anyone know if they sell this stuff in smaller rolls via online or somwhere else. iam in MN........One thing that is frusturating is that I kept hearing I could use landscape fabric.........which is not true according to everything that i have read on this site and the ICPI site Right?,,,,,,,,, after descrbing thats its not landscape fabric finally they find someone who knows what their talking about but then informs me of only stocking the product in huge rolls..........

    So I really hope it can double as landscape fabric????????
    And what brand/brands??????????????////
  10. Rex Mann

    Rex Mann LawnSite Senior Member
    Messages: 621

    I'll send you the amount you need for my cost plus shipping. Let me know.


    Rex Mann

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