# Dish mounted on Roof Installaion questions...



## Codeman00 (Dec 13, 2003)

Installers, I have a few questions...

1) Is it safe to drill through your roof to mount a dish? I know that the proper sealant, etc needs to be used but it doesn't seem like a good thing to put holes in your roof and hope that the sealant holds....or is it not a big deal?

2) Do you also drill a hole for the coax cable to go through the roof or typically run the wire somewhere else to feed it in the attic, etc? Can this coax cable be sealed easily to prevent leaking?


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## FTA Michael (Jul 21, 2002)

1) Sealant Good! Put it where you drill the holes and along the threads of the screws.

2) Drill a hole in a side wall for the coax. Add a drip loop in the coax line to the side wall hole. And you're grounding everything, right?

You might want to head to your local library to grab a book about all this.


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## Codeman00 (Dec 13, 2003)

1) Actually, I'm not doing the install...I'm buying a new house and I don't see any way that the Dish Mover installer can mount the new dishes unless he goes through the roof. Its my first new house and I cringe at the fact of drilling holes in a new roof for the dish after reading stories about installers not doing it right, etc. So you're saying if its done right, I shouldn't have any problems and I shouldnt be worrying?

2) So you don't go through the roof with the coax..you mount the dish on the roof at the side of the house and then feed the wire through an eave or soffet? Actually, I don't have an eave on that side of the house so I worry about that.


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## Richard King (Mar 25, 2002)

Whenever I had to do a roof installation I tried to keep the dish over the eaves of the house so that if the install leaked at all it would drip into the eaves area, not the occupied area of the house. That's hard to do if you don't have an eaves area where you want the dish.


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## Mike500 (May 10, 2002)

*Roof mounting*

Roof mounting is better than mounting at the bottom of gable facia boards that are only 3/4" thick.

Mounting on a pitched roof is actually preferred, if done right. Never mount on a flat roof or within 2 feet of a valley. The strongest mounting point is at the corner of the house right at the convergence of the wall corners and the rafters. The rafters are easy to find there. Movement will never be a problem.

Never "glue" the dish foor to the roof with silicone or roofing cement, like it advised in the self install manuals. Don't predrill holes for the mount, and don't use 1/4" or 5/16" lag screws. Use 1/4" (#14)x 3 inch hex head drive hardened sheet metal screws. If you can't find them at hardware stores, Home Depot sells small packages under the Simpson Strong Tie brand. They will about never break like lag screws. Drive one, without predrilling through the center round hole through the shingles into the rafter. Plumb the pole in the up/down swing direction. Tap the foot in the corner until the pole is plumb in the opposite 90 degree axis. Drive the second three inch screw in the crescent slotted center foot axis hole. Drive four 1/4(#14)x1-1/2" long hex head hardened sheet metal screws into the corners, just enough, since these can easily strip out as they are going through shingles or light OSB or plywood flashing.

Actually on a pitched roof, no sealing is necessary. The heat from power driving the screws, without predrilling melts and displaces the asphalt from the shingles around the screw and rehardens. Just to satisfy the customer, I might put some sealant on the screw heads. *Thick layers of tar makes for an ugly install and does no good.*

When it comes to dish removal time, remove the screws. You are left with six less than 1/4" diameter holes that are easily sealed. The shingles do not come off with the mounting foot, as if it was "glued" to the roof. A dish foot "glued" to the roof will not keep the dish on the roof during a storm. It just takes the shingles off with it. Fastening the dish to the roof means screwing into the roof.

Re-roofing and realignment is easy. Snip off the head six 16d (penny) nails and place them in the holes, with the dish removed and the points sticking out about 1/2." As the roofer puts down the roof, the points will protrude through the shingles. Put the dish over these protruding nails. Pull the nails out one at a time with pliers, and replace each screw into the same place that they were taken out.

*How to install a roof cable entrance.*

I'd go out and get a piece of 1-1/4" PVC conduit, a couple of same size 2 hole clamps, a service entrance head, and a vent flashing.

Go into the attic, using a 1-3/4" hole saw. Start it flat with the sheathing right next to a rafter. As it it cutting part way through, tilt the hole saw, until it is plumb. Outside; using a large putty knife or a dry wall taping knife, carefully lift the shingles around the hole. Remove any roofing nails at least a foot radius around the hole. Place the flashing over the hole, and cut a circular "U" out to match the flashing raised area plus 1 inch all around, starting at or below the center of the hole. Slide the flashing under the shingles, matching the raise area. Shove an 18 inch long piece of pvc conduit through the flashing and the hole in the sheathing. Inside the attic, strap the condiut to the rafter. Outside, nail down the bottom corners of the flashing and replace any nails taken out that held the shingles. Glue on the cable entrance weatherhead.

This is the correct and truly professional method for a roof entry.


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## BaldEagle (Jun 19, 2006)

Great post Mike. Very informative.

Thanks for taking the time to share this.


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## Codeman00 (Dec 13, 2003)

Thanks Mike!


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## Rovingbar (Jan 25, 2005)

I recently had a 'dish mover' installation on the chimney casing. The installer lifted the flashing at the base of the chimney and ran the lines into the attic. It doesn't look very good and I'm worried about water getting in now that the flashing is lifted 1/4" for the cables.

Also, he did not run a ground line! The DP34 switch is grounded. Should I run a ground line to the dish, or am I OK with the current situation. BTW: I have surge protectors on most of my equipment.

Jeff


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## Rovingbar (Jan 25, 2005)

OOPS, I forgot to specifically ask for recommendations. Would it be worth while to pay a roofer $100 to fix the dish wires, or is this installation acceptible?

Thanks,
Jeff


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## Mike500 (May 10, 2002)

Jeff,

What you call a chimney casing, is actually called a *chimney chase.* A *chimney chase* is bascally a decorative wood framed structure to cover and enclose an insulated metal stainless steel lined chimney.

From your post, you do not state where the DP34 is mounted or state what the wall sheathing and the siding material covering the chimney chase.

The cables should not be routed under the chimney flashing. Wind driven rain will cause water to enter the opening and eventual rot and water damage, which may not show up except during a heavy continuous rain storm.

The grounding screw on a DP34 is not a valid ground for NEC purposes. You really need a UL approved grounding block. Ideally, the grounding block should reside in a weatherproof box outside of the structure and a #10 gauge copper conductor routed to the house system ground.

The entry point for the cables into the chimney chase should be at least 9 inches above the roof deck, if on the downslope side or 12 inches, if on the upslope side. If you have vinyl siding, you can easily make a weatherproof entry by lifiting up one panel of the siding and drilling a hole for the cables. Cut a channel slot on the upper part of the top of the lower course. Cut a matching slot on the lower hooking lip of the siding you lifted up. If you reclip the siding, it will cover the entry hole in the sheathing and provide a weatherproof shield over the cable wntry hole.

It will make a very discrete entry for the cables.


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## Rovingbar (Jan 25, 2005)

Thanks Mike,

The chimney chase is exterior paneling, no vinyl siding.  The dish is mounted near the top of the chimney on the downslope side. It is about 4 ft above the roof decking.

Can I drill through it near the dish? Should I do something to make sure the cables don't come in contact with the chimney? How can I seal the hole? Do they make some sort of elbow that I can point down, or should I use silicone caulk to seal the hole once the wires are passed through.

The DP34 switch is mounted to a rafter in the attic about 100 ft away from the dish. So I figured it wasn't a very good ground even though there are thre wires.

It seems that I will have to run a ground wire. The central air unit is right next to the fireplace, so I could proably find a good ground wire near the bottom of the chimney. Otherwise I'll have to run a ground wire 120 ft or so to the ground post by the electrical box.

Thanks,
Jeff


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## Mike500 (May 10, 2002)

Jeff,

You can buy a grey one inch PVC service entry head (Home Depot or Lowes), but instead of gluing it to a piece of PVC conduit, using a hole saw, cut a hole in the side of the chimney chase, and glue the entry head to the side with silicone, with the cable openings pointing down. Just fasten the cables with clips, so that the cables are at least one inch from the metal pipe.

The grounding block should be mounted with the connectors mounted horizontally. The cables should have a downward slope away from the connectors to form drip loops.

There is no need to ground the DP34.

Hope this helps,

Mike


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## Rovingbar (Jan 25, 2005)

Thanks again mike. I'll be working on that service head entry this weekend.

It looks like the installer left the grounding block hanging in my attic. I've got quite a bit of work to do to fix this.

I will mount the grounding block about 1 ft below the dish, and put the service entry head about 4-6 in above the grounding block. Of course I will run the wires with about 1 inch drip loop. While I'm at it, a nice new ground wire should finish the project.

Thanks for all the help mike.
Jeff


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## cdru (Dec 4, 2003)

Mike500 said:


> The grounding screw on a DP34 is not a valid ground for NEC purposes. You really need a UL approved grounding block.


Can you back this up with any further information? Properly placed, I see no difference between the ground screw of the DP34 and the ground screw of a grounding block.


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## harsh (Jun 15, 2003)

Codeman00 said:


> 2) So you don't go through the roof with the coax..you mount the dish on the roof at the side of the house and then feed the wire through an eave or soffet? Actually, I don't have an eave on that side of the house so I worry about that.


If your house faces East or West, sometimes they will mount the dish on the South facing wall and avoid the roof altogether.

If your overwhelmingly concerned, you can negotiate a price for a ground pole mount.


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## Mike500 (May 10, 2002)

cdru said:


> Can you back this up with any further information? Properly placed, I see no difference between the ground screw of the DP34 and the ground screw of a grounding block.


Grounding blocks are UL listed as a valid ground to comply with the IEC and NEC. The ground screw on a DP34 is not. Echostar rules require a GROUNDING BLOCK.


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## tbone2004 (Jul 31, 2006)

Guys,
which of these two areas would you recommend I have them put the dish - on corner edge of roof or attach to side of house (see pic) Sounds like I would have more wood to grab by corner of roof install - or is it too exposed to wind etc like that? Not sure the guy would catch a stud going through side wall. I was going to have the 4 cables (yes, those things that look like legs)  coming off it go up into the soffet. I guess the grounding block & housing would be located somewhere near the dish as well?

The roof install would require the 4 wires to go over the gutter that will be there.

Suggestions please....


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## Nick (Apr 23, 2002)

Be sure to use a drip-loop anywhere a cable or wire enters a structure.
Doing this will help prevent rainwater from running along the line and
into the structure.


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## audiomaster (Jun 24, 2004)

Rovingbar said:


> Thanks again mike. I'll be working on that service head entry this weekend.
> 
> It looks like the installer left the grounding block hanging in my attic. I've got quite a bit of work to do to fix this.
> 
> ...


Ideally the ground wire would run from the dish directly to the ground rod at the electrical service and should be at least #6 wire. remember you are counting on this wire to divert a lightning bolt to ground. Connecting it to the ground at the AC unit might only divert the strike to that expensive piece of machinery as its ground wire may be too small for both it and the dish. ! The ground block should also be connected to this wire. And try to keep it clear of anything easily flammable and do not route any part of it inside the house. The ground block is supposed to be installed where the cable enters the structure on the outside. Not in the attic. You don't want a lightning bolt flying around in a dusty attic full of paper boxes etc.


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## Nick (Apr 23, 2002)

Just a note about grounding -- clamping the ground wire to a ground block also
electrically grounds the dish through the cable shield. Keep in mind, though, that
a ground is not intended to protect the dish, but, rather, to keep electrical charges
from entering the structure.

Also, please note that the NEC has somewhat of a different view of the use of
"driven" grounding rods.

http://ekb.dbstalk.com/87

http://tech.dishnetwork.com/departmental_content/TechPortal/content/tech/techmiscgrou.shtml


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## Larry Caldwell (Apr 4, 2005)

tbone2004 said:


> Guys,
> which of these two areas would you recommend I have them put the dish - on corner edge of roof or attach to side of house (see pic) Sounds like I would have more wood to grab by corner of roof install - or is it too exposed to wind etc like that? Not sure the guy would catch a stud going through side wall. I was going to have the 4 cables (yes, those things that look like legs)  coming off it go up into the soffet. I guess the grounding block & housing would be located somewhere near the dish as well?
> 
> The roof install would require the 4 wires to go over the gutter that will be there.
> ...


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## Larry Caldwell (Apr 4, 2005)

Nick said:


> Also, please note that the NEC has somewhat of a different view of the use of
> "driven" grounding rods.


The electrical service ground meets NEC code if as long as it presents less than 25 ohms to ground. Astonishingly, you can connect a 20 amp, 120v. breaker directly to the system ground, and quite often the breaker won't trip. The neutral is also bonded to the ground at the service entrance, so most electricity just runs back through the neutral to the center tap of the transformer.

While the service neutral and ground are bonded together and will be at the same potential, a separately driven ground rod will often have a different voltage. In the case of a short, there can be many amps available behind that voltage. This voltage can really screw up the operation of low voltage equipment like LNBs, switches or the satellite receiver.


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## harsh (Jun 15, 2003)

Rovingbar said:


> Of course I will run the wires with about 1 inch drip loop. While I'm at it, a nice new ground wire should finish the project.


While a bend radius of 1" is minimal for a ground wire, the minimum bend radius for RG6 is ten times the outer diameter (OD) of the cable. With most cables, this ends up being a radius of at least 3". The loops for RG6 can be larger, but they should not be smaller than 6" in diameter or the cable's properties may be adversely impacted.


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