Old Home Woes

Wiki Projects & Stories
1

I thought I would ping the hive mind here, as I am at a loss. So I am helping a friend get ST up and running in her home, as she like what I have done with mine. He goals are

  1. smart dead bolts front and back
  2. control over an exterior light where the switch is located in a storage area.

Seems pretty simple right? Well the home is ~120 years old. It was built without electric, I think most of the old gas lines are still in the walls. The walls are lap board and plaster. And I am guessing some of the lairs of paint are lead.

We started with the Hub, 2 of the iris Zigbee/zwave plug-in adapters, and 2 GE in wall z-wave switches. We got the zigbee sides of the Iris plugs to work quickly and without issue. The Zwave sides were all kinds of fits, but finally got them to connect. We also got 1 of the GEs to connect. Looking at the logs, the zwave sides never connected again after the inital connect. And the 1 GE that connected kept falling off.

Fast FWD 2 weeks, and we work on it again.

I bring a GE Zwave plug in module that I had been using at my home over the holidays. I had removed it from my hub. At this point my friend had moved the hub to the first floor, and placed it on top of a china cabinet that is as close to center of the house as we could get. So the hub is about 7 feet up in a room with 10 foot ceilings. Yes it is flat, on wood. At this point I cannot get the GE plug in module to connect. I can’t get the zwave side of the iris plugs to respond. a zwave repair says every device fails to update. We move the irus plugs into the same room as the hub, and still cannot get it to run a zwave repair without failing.

She runs to bestbuy and buys a new hub. (side bar, she got her V2 hub nov of 2015, it sat in a box for a year before she got around to proceeding with this project). New hub, in place, The GE plug in module connects right up. One of the Iris modules connects right up on the zwave side. At this point I am hopeful, that the old hub was bad and that was our issue. I move the GE module to the second floor, half way between the hub and the outside light that we want to control. BAM!! that GE switch paired up!! I think things are going well. But I cannot the the other GE switch to pair up. It did respond when I did the general exclusion to get it off the old hub. I move one of the iris plugs to the second floor, run e zwave repair, and all devices fail. The GE plug in module stops responding, the GE switch that did pair stops responding. I fuss with it more. I move the GE plug in to an outlet on the second floor that is ALMOST directly on top of the area the hub is in. We est it is about 5 feet from the hub on the first floor to the plug on the second floor, and we still have issue.

We ran out of time, so the project sits. The Zigbee devices have no issues so far, it is just zwave. She is going to see about getting more of the GE plugin modules, to see if we increase the density it will help. But I am at a loss. Any one have any ideas?

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Almost certainly the plaster walls have what is called “lathing” inside them, which is chicken wire basically. Makes it almost impossible to get signal through. And the remaining pipes in the wall just add to the problem. For complex technical reasons, zigbee may do a little better than zwave, which is probably what you’re seeing.

It’s likely that you are going to have to approach this The same way that someone who has Adobe or cement walls does. That is, you are going to need to bounce the signal out through doorways or windows rather than trying to get through the walls.

Zwave is limited to a maximum of four hops between the hub and the end device, so some people in cement homes end up putting a hub on every floor and treating each as its own location. Zigbee home automation (ZHA), which is what SmartThings uses, allows for 15 hops into the hub and another 15 out, which gives you more flexibility. Another plus for zigbee in this kind of set up.

Because the signal is attenuated by the lathing, you’re also likely to need a repeating device in every room. Remember that only mains powered devices repeat. (Battery operated devices do not repeat because it would use too much battery life.) typical repeaters are light switches, plug in pocket sockets, plug-in sensors, and in wall relays, although the in wall relays may not help much if the problem is inside the wall.

One more alternative is to see if by chance the Wi-Fi is working better than the Z wave. It may or may not. You can go to boosted Wi-Fi, but then it is likely to drown out nearby zigbee devices. But with Wi-Fi you don’t have to worry about hop limitations. Or repeaters.

So if I were in your friend’s situation I would get 5 pocket sockets, two zwave plus, two zigbee, and one Wi-Fi. Then just start experimenting to see where the dead spots in the house are. The Z wave can repeat for each other and the zigbee pocket sockets can repeat for each other, which lets you find dead spots easier, so that’s why you’re using two of each of those.

The following is A WiFi pocket socket with smartthings integration. Get the newest one, the isp8, to test with.

Once you find out where the dead spots are and how the different protocols compare, you can start making a plan for device selection.

Let us know how it goes. A lot of network deployment in old houses is just trial and error, but fortunately smartthings that you choose from multiple protocols, which should help. :sunglasses:

I should add it’s definitely also possible that the first hub itself has a bad Z wave radio. Check the IDE for her account and make sure under the hub it shows Z wave enabled. But it sounds like the second hub did better, so it’s probably local architectural issues.

4

Also, you probably already know this, but I just just wanted to mention for those finding this thread later that the iris plugs don’t turn the power on/off from Z wave. So for example if you plug a table lamp into it, a zwave command can’t turn the lamp on and off. Their Z wave radio is just a separate device inside the case which can act as a zwave repeater, although a number of community members have reported that it’s a little flaky for that. So I would not use the iris smart plug to test the quality of your Z wave network. Get a separate Z wave pocket socket for that. You can use the iris plug to test the quality of your zigbee network, that’s fine. :sunglasses:

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5

Yea I know that actual switch runs on zigbee and is reported to have a zwave repeater. The idea was there would help the mesh on both zigbee and zwave. I think you have just reinforced my idea the we are going to have to go with a higher density of devices to get this to work. I tried to get her to look at the GE Zigbee switches as an option, but they seem to only come in decora style and she like the more traditional ones.

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6

I have set up ST in my house, which is 111 years old. SO, this is my experience, YMMV.

Plaster and lathe walls are great. As long as they are less than 100 years old. I have replaced about 2/3rds of mine as I upgraded the electric. My guess is that you have two fold problems.

The first problem is that you likely do have chicken wire in the walls. In my house they used horsehair to reinforce the thick plaster. In the 20s, just before drywall, they would put up the wooden lathe strips, slather on one layer of plaster, let it get tacky, smoosh in chicken wire and then slather on a second layer, building the wall thickness to about 1/4 inch. The problem is that the chicken wire touches grounded metal and thereby creates a Faraday cage for all frequencies above the size of the holes in the chicken wire. This is the same reason your microwave has that metal plate with holes in it so that you can see through, but not get zapped. The problem for you is that you have no good way to measure the holes in the wall mesh and would have difficulty figuring out what frequency that size converts to. So, yes, you are going to have to essentially work your way around the house by line of sight. Be aware that the mesh will have rusted through in spots and thereby create holes in the Faraday cage, so you will get occasional areas of spot reception.

The second problem is that you likely have old electric which has crappy grounding. Transmitters work in part by energizing crystals and then dumping the zero energy pulses to the ground. If you have bad grounding it will significantly reduce your range. So realize you may be able to increase the range and efficiency by working the grounding in your house electric.

So, now you can see why my drywall guy loves me. But I have replaced a lot of wall and my wireless and ST networks are great.

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