Motion Detector Retrofit - Anyone Have Any Tricks?

I am continuing to move through my Elk M1G security install. I have purchased several Honeywell DT-7435's and am in the process of identifying the best locations. It looks like a few 45 degree corners on outside walls (read insulated) are in my future. I have a basement and am typically drilling and fishing up through the walls. Theres a 2nd story above, so there's no coming down from an attic option.

I can't possibly be the ifrst person to fish/wire a motion into an existing home that's alread finished. I've searched and searched and searched and can't find anything on the net that can help me. How is this done leaving a clean install? Theres a stud in each corner 90 degrees (perpendicular) to one another behind the drywall. The motions don't span the corner past the studs. It seems like I need to come out next to the motion just to the outside of the stud, but this is going to have to be some precision fishing and a hole and exposed wire next to the motion does not sound like a clean install. There's got to ba an answer for this (no, not wireless motions). I need to know what the pros do.

I would like to attach a few pics to illustrate an example corner, but I'm well over my 100k limitation. These pics were taken when my home was built in 2005. this is an actual corner where I need a motion to go. The room has been painted an actual color since then.

Any tricks would be vcery much appreciated.

Really, it's tough to say without seeing the house. My father and I just started the wiring on his 4500 sqf house and managed to get pretty good 1st floor motion detector coverage with just 3 of them and not a single hole in the wall. Some ideas - drilling straight through a wall into a closet or garage and using the trim around openings to hide wire behind (a lot of passthroughs are along the outside wall, but bump out 3" making them perfect for use). Other than that by using sticks you can fish wire comfortably through a hole as small as 3/4" - smaller if you have magnetic tools.

This is a great topic and I'm glad you brought it up...I've just been searching, searching, searching for the same info and looking for advice on what the pro's do (that said, sometimes the pro's aren't that great...I've seen Pro's install the EOL resistors right on the panel... really!?).

Also, I think you meant 90 degree corners unless your house is shaped like an octagon... ^_^

Anyway, back to the topic at hand, I'm in the same boat as you...when I did my ELK install at first, I installed GE wireless motion's and not happy with them (false alerts), so I recently bought some Bosch PIR+MIR detectors, but obviously these need a wire, and as seems is always done, they go in a corner of the house (external walls with insulation), facing away from windows, to me the hardest place to run a wire. I have a slight advantage in that I took video of my house before the drywall went up and I'm reviewing this and trying to come up with the best way to do this, but definitely any advice from pro installers who do this all the time would be great.

I have used a long flex drill bit for interior motions. About 1/4" dia by 5' long. Don't really need that long but they come with small holes in each end to attach wires. Drill up at an angle so you come out in the attic (This doesn't help on lower floors) attach the wire and pull back to fish the wires. Just have to be careful about aim so wire comes out in the attic where you want and you don't hit any other wires.

Some "pros" just tack the wires to the drywall.

Some corner/crown moulding might come in handy to hide the wires and avoid getting into the insulation.

Fishing wires is always challenging but with some thought you can usually find a reasonable path without too much work.

It is challenging and more of a skill than knowledge. For my basement I have typically removed the baseboard. I run vertically down then horizontally behind the baseboard, you may have to cut a channel in the drywall behind. I carefully reattach the baseboard (making sure not to nail where wires are run, recaulk, repaint the walls. On outside concrete walls there is typically a large gap between the framing and the outside wall, so in that case you can usually pull wire behind the wall horizontally.

Another thing I have done for my projector wires was to push conduit along the ceiling and pull wire through it, which works if the joists align in your favor. If you go for ceiling, you are probably into some drywall work. If you look at my site below you can see what I did to run projector and speaker wires in my finished basement.

I have 2 fish tapes, pull rods, but my favorite wire pulling tool is several wire hangers I taped together using electrical tape. Also another unusual tool that really worked best for me in insulated walls is a tape measure. There have been several times I ran wire vertically in ouside walls with insulation and no matter what I did I couldn't find the fish tape in the hole, but somehow like magic if I pushed a tape measure down the wall it was always there in front of the hole waiting for me...

wuench said:

...you may have to cut a channel in the drywall behind.

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You could use a dremel. Not sure what the thought is on this, but if you channel out the corner you may be able to get away with a paintable flexible caulk so there would be very little work to do and the touchup paint wouln't have a chance to "flash" since it's wedged in the corner.

wuench said:

Also another unusual tool that really worked best for me in insulated walls is a tape measure. There have been several times I ran wire vertically in ouside walls with insulation and no matter what I did I couldn't find the fish tape in the hole, but somehow like magic if I pushed a tape measure down the wall it was always there in front of the hole waiting for me...

Click to expand...

I'll have to try that next time I'm in a jam.

I originally had a motion detector in the corner of my living room. It just happened to work out this was NOT the best place for it, so I had to move it elsewhere.

But I ended up channelling through the drywall corner (basically cut the existing tape from the inside corner, dug out the two pieces of drywall where they met, then put the wire in there and re-taped over). You cant tell I was ever there.

Interestingly enough, Ive read that detectors work better when you walk across them than towards them. To me that means they should be placed perpendicular to the "path of least resistance" for an intruder. In my case it meant not tucking them away in a corner, so its a little more intrusive, but the reality is its not bad at all, and I know 100% that it works a whole lot better that way than when I had it in the corner.

In retrofits, a lot of times the exterior walls are just too hard to do. I know the old rule of thumb has been to avoid windows, but you can really combat that well with a high-quality dual-technology PIR. Both technologies have to be tripped which seems to fix the hot-window issue.

As far as tools of the trade - I use a wet-noodle often and just cut holes where I need to so I can get in with a drill and get the wires where I need them; after I'm done, I have a good drywall repair guy (the same guys that the home warranty company uses) that can make the repair invisible and that can be better than wasting a day hacking around to get a wire into position. I have fish-tapes but I never use them for walls... a set of Fiberglass fish poles can be a lifesaver... I have a 4ft glow-in-the-dark one I use for close and extremely flexible pushes, and I have a large set of bigger ones that screw together as you go in 4ft sections so you can keep attaching and pushing through the wall/ceiling as you go. tip: that set is great for outdoor cameras and speakers; drill a hold, then keep attaching ends as you go and point to the attic opening - then a quick trip in the attic to attach the Cat5 and pull back out, terminate, and connect... saves me from having to risk life & limb by walking across the ceiling in the main living area of my house that has 20ft ceilings.

I've never had great luck with the super long bits going where I want them to go just by flexing them - the tend to get bound up in things.

@Chris- movement across the pattern is key, however corner mount is typically best IMO. You're trying to pick someone coming in from outside, not someone moving towards the detector from inside. A lot depends on the room and layout of furniture, but dead center on a wall, unless you're looking down a hallway or alley isn't good use of a pattern. Part art form, part really knowing the performance of the detector that's being installed.

For installation, part of the method depends on your area of the country.

Diversabits are bravery for running through walls. All I can say about that.

As far as how it's done, I use my #2 Klein to make the hole for the wire and feed about 3' doubled up into the wall. I have a snake, about 12' long, cut from a normal snake, with a small hook on it. Slight bend so it rides up the wall, either sheetrock or outside. Feed up the wall, towards where the wire is, then spin 90 or 180*, pull down and feel for drag on it. Lather, rinse, repeat.

Part of the secret is to NOT use the cheap snakes available now at most home stores, those are only good for uninsulated walls or conduit. Buy a 1/4" steel snake or anything heavier than the normal 1/8" light metal ones. They stay straighter and go up easier. That said, I still coil my snake to fit in my drill case and I don't always use a real heavy snake either. I've found, now that Klein and Ideal ones are both very light steel, that Greenlee or GB seem to be a little heavier and work better.

Rods typically will not work well in insulated outside walls unless you're trying to meet holes that already line up, such as via a diversabit and window method. Wet noodles always fail in fiberglass walls.

A lot comes down to skill. Surface wiring and closet shots should only be left when there's no choice or the damage from attempting to conceal wire isn't practical.

The reason I've had good luck with rods is that I cut access holes at times - maybe we're talking about different scenarios... For example, adding a keypad in an exterior wall - I cut the recess hole for the keypad, then I can reach my hand in and guide the pole where I need it. As for when the holes don't line up, I'm not sure how anything would get through that! And you're right about wet noodles - they're good for when you need the smallest possible hole in a hollow wall - it's super easy to grab them through a hole no bigger than the wire itself and faster than the hook method. I refuse to accept surface wiring ever if I have control - in extreme situations I've build/extended soffits but visible wires are the ultimate in unprofessional appearance, regardless if they're in a closet, etc.

I think an extreme amount has to do with the construction details and practices within the area of the country you live in. What works well in the midwest is like seeing a dinosaur here. A Florida style block construction is almost unheard of here, but mention baloon framing or post and beam in the Gulf coast and you'll get the deer in headlight look.

I've found that rods have their place, but in an outside wall, the problem I've run across is they ride up the outside wall, and unless you tie a wire or string to snake to, it's somewhat cumbersome. The amount and size of holes we're cutting the majority of times is a single gang, and with many trims, there's little room for error after cutting in a MPLS, LV ring or old work box. Call me old-school, but instead of a wet noodle, we've always used jack chain and a magnet, or in other cases, a "mouse" made up of mason twine and a small piece of lead.

Usually, in a lot of our cases, visible wiring in a closet is minimized to get around certain construction details where cutting isn't desired or an option, basically run from where you can snake, say vertical to a horizontal run. Painting/patching by others, while nice to put on a contract, is usually cause to lose a contract or a point where people start to look for a discount when really shopping a contract. Nice to have on a large, tough integration, but for a run of the mill system, the HO isn't going to go for it when the "Geeks" or "APT Security" aren't addressing such.

Yeah you bring up a good point - construction varies greatly from one region to the next, and also from one time period to the next (every decade brings different features around here thanks to ever expanding code related to efficiency).


The great thing about experience is you learn what tools you work for you and you get good with them. Over time, you develop tools and technique to solve almost any problem.

Yeah I played with a few locations for our motions. My house is setup where there are stairs all the way to one side of the house to go upstairs. Since my primary goal is protect people in the house, I set it all up for the situation of someone breaking into the house and attempting to run upstairs (assuming they arent daring enough to break in during daylight). To do that, they would need to CROSS the motion sensor. I originally had it in the corner at the bottom of the steps, and even *I* was able to get past it without setting it off. Its kinda a "great room" and there are obstacles in the way that would prevent the motions from working their best as well.

For other rooms I went with normal corner mounting. Just the great room needed some fudging.

We've talked about DiversiBits I think they are OK (even from newbie me), but the key for me was to drill thru the window RO, then stop drilling and "feel" the drill bit as I pushed it thru the stud cavity. Eventually I came to know when I hit something that WASNT the sill plate of the wall (when the bit hits wood, it gives you a different thunk/feel than when it hits metal, etc)

I used fiberglass fish rods almost 100% of the time to fish the wires when I didnt have access to the end of the bit. For most of the wires the DiversiBit worked great.....I could go into the basement ceiling and access the bit to wind some of the contact wire around and pull the bit back up. For complicated stuff that needed to be fished around, etc, I used fiberglass rods and access holes. Kept most of the access holes in closets so "when I get to it" I can patch them up. I suppose it might be a "what works for you works for you" thing, but I found what works for me (luckily) and Im just about done puling wires finally

Diversabits work great in certain applications. Hell, I have about 20 of them, with my favorites being either the 1/4" HSS or 3/8" augers, but I've got up to either a 1/2 or 9/16" one, just to get out of a jam for whatever reason. If you're working by yourself and the window and wall construction allow their usage, they can be a good timesaver and I've done 5-6 of them at the same time to minimize trips up and down and speed up the process, so they do work, but a lot of times, it is common to end up in the joist or in a spot where the wire can't be tied on, and I've moved back to a snake and traditional methods to get the wire to the hole. I wouldn't, however, as a lot of the pictures show, drilling down from a light switch height to a basement or similar.

I've used them (judiciously) in the past to drill sideways through 2 bays on a window in a house where the openings were framed after the wall and the sills went all the way to the next stud bay. Also did the same for some 2nd floor windows to shoot them into a closet, then up to an attic. Same goes for drilling a door contact across a finished wall to an unfinished basement in a split level entry. They're also pretty nice to use in blown in insulation as a stand in for rods (or to minimize the trip to the attic). They're hit and miss in spray foam, but I've resigned most HO's that go that route for insulation that it's either rough in or plan on using RF because of how intensive the labor is in running wire after the fact....I refuse to provide a flat price on those jobs anymore and bill it as T+M.

As you stated, part of the art is "feeling" what you're going against, combined with a heck of a lot of checking before attempting to use them. I've heard and seen guys use them to skate down a stud within a wall or up into an attic, near existing electrical....very scary and brave if you ask me. I've also seen people drill either to the outside of the house or through the sheetrock towards the inside with them when they skipped along the bottom plate.

There's no magic wand when running wires, usually it's skill and experience that wins, as well as some creative methods (I've pulled and cut subfloor under carpet and used diversa's to get to the joist bays). A lot can really be learned in wiring home systems from a skilled LV installer that does a high % of retrofit work, as most electricians don't have the same skill sets to get wire to the same locations with the same holding true in those guys that predominantly do new construction.

Thinking about the motion around the staircase... one thing to point out - if you're looking for the best coverage, you might want to see the staircase; if you're designing a system around pet-immune sensors, staircases will do you in! Even a 100lb pet immune sensor will trigger from a 15lb cat that makes it up too high vertically in the sensor's view.