On 5/11/2014 2:18 PM, Patrick Greenlee wrote:
Grant, PVC S&D (Serer and Drain) pipe is also available in 3 inch. I
have both 3 and 4 inch in service as conduit. You do need to be a
little more cautious when back filling over S&D as it is more subject
to rock damage and the like. In this region both Lowes and Home Depot
have the 3 and 4 inch for less than the price of sched 40 PVC water
pipe and since I'm not pressuring the conduit I go for the savings.
The S&D has some nice sweep L's which I like for ease in pulling cable.
As you will notice in the 5th photo
http://www.rogerhalstead.com/ham_files/cablebox.htm The lines are
leveled as the backfill is put back.
I used the thin wall drain pipe. At the far end there is a "Y". Rather
that an external trap that would fill naturally every time it rained,
the "Y" is separated from the rest of the run by a thin bulkhead with a
couple of simple 1/8th" holes at the high and low points so the trap can
breathe The trap is filled with pea gravel and has a single 1/8th inch
drain hole at the base.. BTW the entire back fill is covered with 1"
Styrofoam and never freezes. It's protected with 2 to 3 inches of
crushed rock.
Were I to do this again, I'd make the trap, at least 3 or 4 feet long,
filled with pea gravel and with a small drain hole at the base. It's in
the sand back fill for the basement wall which is "relatively" dry, year
round. Powder dry in the summer except for brief periods after storms.
In the winter, it remains dry below the frost line.
That can, drain, "what ever" needs to easily hold all the water with
plenty of room left over. It should not be located as to create an
ingress point for water into the conduit.
If you really do need a "dry well", look into the design carefully.
This would be my approach: 1. The dry well truly needs to be dry. It
should not have water setting in the botton if at all possible. 3. I'd
not use steel or crocks that readily cause condensation. 4. It should
extend well below the frost line
5.It should be capable of draining!
These are just ideas as each installation is pretty much unique and has
its own requirements. If you know an engineer, try to "bleed" a little
specific information. If you don't know one, try to make friends with one.
For lack of better materials, depending on size, I'd use a group of
appropriately sized thin wall drain pipe. 4, 5 6, inch or what ever,
into a plenum. A small heater and fan could be used to exhaust the warm
air out into the atmosphere from the plenum
I have several areas (NW corner of the lot) where the only conduit route
would be to seal and purge with dry nitrogen. Fortunately I've had no
need for waterproof conduit in this ares. I'd go above ground if necessary.
Do not exhaust the warm air into the conduit, unless you have a large
heater and big fan, otherwise you will just build up a lot of
condensation in the conduit!
73
Roger (K8RI)
73,
Patrick NJ5G
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