What do you all use for bedding material when laying sewer/storm mainline? We have to use sand in my city, and i don't really like it. If youre using something like pea gravel it will fall around your pipe nice and easy, and you dont have to worry about compaction like you do with sand. Guys have laid pipe using sand and it looked good when they laid it, but after a few months, or even after compacting once they backfill, the pipe will be diving up and down allover the place.
i prefer a 3/4" crushed rock. but it gets expensive. pearock is okay unless you're in a wet clay situation where the pearock doesn't have enough bearing surface to hold up the pipe, it just mushes out. for us, seems the most cost effective is 6" of crushed rock under the pipe, and then sand for the rest of it
Depends on what the municipality wants. Where we do most of our work, it is required for sanitary to use 2B stone which is crushed stone that is 1" in size. For pressurized lines, it is required to use 1B which is pea gravel. For storm sewer work, we us 2A modified which is unscreened 2B. Like Day said, if we get into some water where it turns the ground to mud, we will throw in some 4" rock and then throw a layer of 2B on it. For phone and CATV it is required to use sand or stone screenings.
For years and years here in the Pittsburgh area, we used slag, specifically "air cooled blast furnace slag". It can be had in pretty much the same grades as gravel or crushed limestone. I'm told these days by the plumbers that slag is a no-no around plastic pipe, becuase apparently it's no good for the plastic. :beatsme There's miles of pipe bedded in slag though... Nowadays, we use either gravel or crushed stone as mentioned above, around sanitary and storm sewers. Some places spec 2b around a foot above the pipe, and 2a from there to the surface, or subgrade. That's a real pain when connecting laterals, because at the end of the lat there's always two feet of it, and when you expose that, it just keeps running into the hole. One of those situations where you seem to take one shovel full out, and two more fall in on top of it. :Banghead Water mains, I've seen speced with sand or just dirt, as long as there's no stones bigger than a couple of inches. Gas, and wire type utilities we use sand, and hope to find everybody else did too, but they don't always...
For underground cable or light pipe use sand for water lines use sand then the dirt dug out of the hole over top the sand. The sand is only maybe 12"s above the pipe. The backfill is carefully dumped into the trench if there is big rocks they are thrown to the side. Once there is enough protection above the pipe then its backfilled with rocks and all. The sand used is unwashed or what we call fill sand its cheap some days it goes on sale for 2 dollars a ton. Pea stone is very expensive same with any kind of washed or crushed rock. Another option is using 3/8s minus it packs good. If the material in the trench is good enough no bedding material is needed just pick out the rocks under the pipe.
The best bedding around here bar none is stone dust or screenings,the waste product from Traprocks limestone crushing operation.It has much better structural bite than a regular grade of sand,whether processed or not such as dead sand.If it gets wet and then dries before you backfill,it hardens somewhat.Years ago,they almost gave it away but now it's priced accordingly.By the way,the quarry is humoungous--largest one East of the Mississippi--when you're standing up on top and half a mile or so away, the yellow dots next to this one shovel are D9's!!:thumbsup
3/4" stone for all sewer pipe. Sand/ Stone dust for water, gas, electrical.
3/4" crushed stone for sewer. Bedding sand for water, electrical, gas.
Tyler, we have nothing but sand here and all our pipes are sand backfilled. You will see an exco company working on the side of the road and they will have at least 3 vertical rammers and probably a water truck to bed in. The specification is for clean aggregate free sand and this means no clay. I can't remember seeing any major problems. In fact, I'm currently digging over and around a sewer that was installed 20 years ago, all bedded and backfilled with sand...its straight as a die.
We use a 57 stone which is screen size 5-6-7 for all sanitary bedding - 6" under and 12" over. DIP water is direct buried and backfilled except for road crossings then all 57 or dense grade backfill. Sand is very expensive ($20 per ton) compared to 57 stone ($5 per ton). Gas lines are backfilled with 8910. We usually bed the sanitary lines with stone and then 1' of spoil and run a roller over it to bring it back to subgrade. We use a 48" roller in the trench and a track loader to backfill. The trench is already laid back wide enough for safety so it is pretty efficient. As far as telcom lines- they usually just pull the sod up, lay it on the ground and put the sod back over. LOL
That seems to be the common thing around here too... We've got a bin full of bedding sand at our yard among other things...