If you have a shed or garage that is detached from your main home and would like to enjoy cable TV and Internet, you may need to run a cable inside yourself. Most cable TV installations do not include running additional cables to structures detached from the main home. That's not a problem–it's a fairly easy process.
Measure the distance from your cable box or splitter to the exterior building where you will be installing the cable. Use a tape measure.
Mark the route of your underground channel using a can of red spray paint.
Dig the underground channel at least one foot deep and about four inches wide using a shovel or trench digger if you have one.
Lay out the PVC conduit inside the channel, cutting pieces as necessary with a hacksaw. Once the route is laid out, assemble the conduit by applying PVC pipe cement to the inside of the connectors and pushing the male and female ends of the pipe together.
Push the end of the coaxial cable into the pipe and thread it through the conduit using a cable puller (a long steel rod used for feeding cable through conduits).
Assemble two 90 degree elbow joints with two feet of vertically oriented PVC pipe. Thread the cable through these joints (one at each end) and attach the joints to the conduit pipe using PVC cement. Leave the cable threaded through these joints as it is difficult to pull cable through a 90 degree bend.
Run the cable from the conduit to the cable box in your home and connect it to the splitter. Run the other end to the TV inside the garage or shed. This may require drilling a hole through the side wall or floor boards in some cases. If so, caulk the hole with silicone or roof tar.
The complete installation may require drilling a hole through the side wall or floor boards of the additional building in some cases. Use a power drill and 1/2-inch bit. Then thoroughly line the hole with insulation and caulk it with silicone or roofing tar.