Hot water in floor heat-add/extend a zone

[mrjigger]

I have a hot water in floor heating system in my basement. The water gets heated with an electric boiler. The whole system is in my basement right below the wall in my garage that joins the house. I want to add or extend a zone into my garage to provide heating for my dog and also to keep boots, etc on. I am not concerned about having temperature control.

Can a Just "tee" off a zone supply, make my loops in the garage and then back again to another "tee" on the return line?

[CAMAN]

Probably not without the possibility of severely effecting the zone you tap in to. Water takes the path of least resistance, and if there is less resistance in the new line it will prefer to take that route over the old line, or vise-versa and cause a cold zone. That is why manifolds are used. If you have an extra outlet on the manifold I would use that, if not I would add one. But it would probably be best to bring in an expert so the system remains balanced and works efficiently.