@TheCastleHouse 

We currently do not have an outdoor product that can work in tandem with the Deco mesh network as far as having a seamless network. You can use an outdoor AP unit and configure it with the same network name and password. Our outdoor AP units can work together as a mesh network (2 or more EAP225-Outdoor), but not with the Decos mesh, they are two different kinds.

@Tony Thanks for the answer. I do have a EAP225-Outdoor, and I am considering to buy a TP-Link Deco M9 Plus Smarthome Multiroom Wifi 3-Pack. 
Few questions:
1 - is it really the same network if I have the EAP225-Outdoor and a mesh unit? I.e. if I have few Sonos speakers connected to the 'mesh' network, and I am with my phone outside in the garden connected to the  EAP225-Outdoor, will I be able to control the Sonos speakers?
2. If I configure the EAP225-Outdoor to have same WIFI, & password, in case I do get some 'weaker' signal from the mesh outside in the garden, how would I be able to connect my phone to the EAP225-Outdoor and not to the mesh?
3. Are there any plans in the (near) future to produce an outdoor element compatible with the TP-Link Deco M9 mesh?

Thanks a lot,
Miki

@MikiM 

1. Yes, it will all be the same network/subnet. I think there were some users mentioning not being able to connect at times with the mesh network?

2. When it moves from the Deco to the EAP it would depend on the device if it decides to move either to the stronger signal or until the signal completely disappears.

3. There is nothing in the grapevine about that, but I wouldn't be surprised (I'm just speculating) if we do as I see more users have an existing Deco wanting to expand to their backyard.

@TheCastleHouse

My electrician put my Deco 9 Plus units inside 8" white junction boxes, drilled a few holes for ventilation, and then put them around my property such that the main house is in the center of a triangle with the main Deco unit inside the house.  The three outside units are on 6 meter poles with clear line of sight between them all.  Great coverage and good speeds all over.  Pool area, gardens, driveway gates, garage, etc. - all covered.

@Estuardolo 

This one is between the pool area and main garden.  The deco is inside the white box and wired to a line supported by our backup generator.  It sits atop 2 aluminum poles (2" x 2" each, ~1.8 mm thickness) which are joined together by long/strong screws set at 2 meters apart.  Two meters of it (not shown) is attached to the pool area wall.  The setup is strong enough for up to *maybe* a Category 4 storm.  We rarely get so much as a Category 2.

The little thingy on top of the box are plastic bird spikes.

Hope this helps.  Cheers!  🙂

Edit:  The box is attached using L brackets.
 

@Tony pls do seriously consider deco outdoor units, you will be surprised how many will be happy i have m9 plus's m5's and m3w's, believe me eap 225 is not as seamless with the system if signals overlap, most devices tend to hold on to the interior mesh node until signal is really low and unusable..

@DrManu_M 

I hear you, I have seen a great number of people too wishing to keep their network consistent. 

This has been presented to our developers for consideration.

@TheCastleHouse 

We have just moved to an acreage and would love to integrate the 'outdoors' with the indoor setup.

we have 3 x Deco M9 Plus indoors (steel framed house) and run a Ubiquiti external antenna to service outside needs.
If TP-Link come up with an external device that would integrate with the MP Plus I would buy it immediately.

Rob.

@RobOK , @Tony - me again. I did decide to purchase DECO M9, I have to say I am super happy (210 m2 house - I have 3 units). However I really miss an outside unit. 
I'm seriously considering to sell my TP DECO system and move to Netgear ORBI because of this reason :-(.