Hi to All,
I am going to attempt to cover a small area in my yard with interlocking paving blocks. Before getting started however, I have some questions about the procedures. Is the correct approach (after digging down 5 to 7 inches) to backfill with a base material, followed by a layer of sand? After tamping the base material, does it also need to be screed or is this done only to the layer of sand? Finally, can the base material be purchased at HD or Lowe’s? If so, what is the product name?
Thanks in advance for your help/suggestions.
T2
Replies
You might want to put down landscape material first. Specially if you have lots of clay.
And if the base layer is "reasonably" flat then you don't need to screed it. The sand will take care of the variations.
What you want is has a number of names and it will very around the country. Here it is called AB3. But road base or 3/4 crusher run, or 3/4 minus should get you want you want.
I have seen it in bag at the home horror stores, but if possible I would get it in bulk. Look for landscape suppliers or sand and gravel suppliers.
What ever you "tamp" do it in thin layers to get max compaction to prevent dips and dives from settling
i put down about 1100 ft2 last summer (and never done it before)...
for a walkway/patio 5"-7" should be fine.
we put down the Class II base rock (thats what they call it here in California) in 2-3" lifts, lightly wetting and compacting each lift with a flat plate vibrator.
we kept the baserock as level as possible, but the sand will help fill in small voids
as for the sand.. we went with about 1" of sand... we used 3/4" PVC pipe as the float strips and used a 2x4 to screed the sand. (in hindsight, we should have used galvanized pipe)
lifting the float strips of the sand leaves voids, so i would toss some sand in the voids and smooth it out with a trowel.
place the pavers down in the pattern you want...
make a couple passes with the flat plate vibrator to set the pavers...
sweep some coarse sand into the joints, and re-vibrate..
im no pro, but thats was what we did... worked out well for us..
do a search on mike flury in the archives... he helped me out tremendously during my ordeal..
You've gotten good advice so far. Here are a few more details.
The base material is very important. The reason crushed stone was recommended was because the variety of sizes and the sharpness of the fractured stone allows it to compact very tightly. What you don't want, in contrast, is rounded equal sized stones. They won't compact.
A jumping jack type of compactor will be much better than a vibrating plate compactor for compacting the base. Base material compacts around 25 to 30%, so for a 4" base you need to apply about 5". It does not need to be screeded, but should be within about 1/2" of the contour you want.
Calculate the cubic volume and order the appropriate amount of stone for the base. It will probably be several tons -- you won't want to buy it in bags. Order it from a stone yard. Have it dumped on a hard surface, such as a driveway, even if it's some distance from the job. Use a flat shovel to load it into a wheelbarrow by scraping the shovel along the driveway. If you dump it on dirt or grass you'll never get all the stones up, and you can't dig a shovel into a pile of stones. Work ergonomically, and limit your shoveling to only an hour or less per night.
Install edging. (The base should be about 6" wider all around than the finished area.) The edging gets spiked into the base.
After placing and compacting the base, I'd recommend stone dust rather than sand. It drains a bit better, and ants don't like it as they do sand. Stone dust is just an especially coarse sand, with particle sizes about 1/16 to 1/8" or so. Screed the stone dust carefully, using something straight about an inch thick as guides. As was said earlier, 3/4" steel pipe is good. Remove the guides then carefully fill the holes left by the pipes with stone dust.
Lay the pavers before compacting the stone dust. Then, using a vibrating plate compactor, compact the pavers into the stone dust. Begin at the perimeter and spiral to the center. Sweep dry sand into the joints and vibrate some more.
By the way, 1/4" per foot is necessary for good runoff. Wear leather gloves when handling the pavers.
Edited to correct spelling typo.
Edited 9/2/2004 9:51 pm ET by WAYNEL5
http://www.pavingexpert.com/
Watch out for the british terminology.
All a DIY'er would ever want to know: http://www.unilock.com/
No brits there, as far as I know, not that there's anything wrong with that ... :)
yet another link...
http://www.paverdepot.com/installation.html
some good pics
can the base material be purchased at HD or Lowe's?
Might be, but you won't be happy. The volumes add up very quickly. A cubic yard is only 6' x 9' x 6" not the biggest of areas. That's 54-55 of those maybe 2 cubit foot bags of gravel down to the big box.
Look up "Sand & Gravel" in your yellow pages for suppliers, you'll be happier. As was noted, get the material delivered to your driveway or other hard surface (unless you have a gravel driveway, <g>).
Don't overfill your wheelbarrow, either. This hard to do without experience (hard to do with experience, too). Having helpers is very good idea, even if only for short periods. ("Free" helpers like relatives, children, neighbors-owing-you-favors, etc., are even better . . . )
I agree that rock dust is better the pavers, it's just harder to find a use for the 1/3-1/4 yard left over (but it can be done <g>).
Yes you can buy it at Lowes or HD but it's a pain. I recently bought about 5 bags and the car got quite heavy. Get delivery at the least. If you buy in bulk, a landscaping supply store will always be cheaper than HD (at least here in NJ). I get my mulch delivered by the yard. Even with the $20 delivery charge, I get almost twice as much mulch for the money over HD.
I think the generic name for the first layer is trap rock. The second layer can be sand although I have heard that stone dust is better. I'm planning on paving my front walkway and will use stone dust.
I prefer to use a fine graded sand (0/30) than course beteen the pavers. It penetrates better to completely fill the spaces.
The final step for best results is to apply SureBond joint stabilizer. It soaks into the sand and it ends up like mortar. Not cheap - $48/gal in central CA - but well worth it. You end up with no loose sand to track around, few or no weekd coming up in the cracks, better water runoff. If you want a glossy look you can apply a second coat; one coat dries clear.
http://www.surebond.com/sealerpaver/index.html