An interesting project came my way today in the form of the following:

6000 sq.ft
radiant heating
wants 5"+ Solid Ipe w/plywood sub floor.

any tips?

I am new to radiant heating.

I would recommend NOT using a solid wood floor product UNLESS it is narrower, strip flooring and is quarter sawn. Even then, it is a risk at best. There is a flooring company that makes a wonderful engineered, unfinished floor with any width and wood you want. Pacific Hardwood is the parent company and FloorLayers is their engineered line. http://www.floorlayers.com/

How you lay the floor depends on the system they are using. If it is tubes directly underneath the plywood subfloor, you may not be able to nail unless using shorter 1.5" staples and the subfloor is at least 3/4" thick. And at 5" wide, you will want to glue as well. Forget any asphalt laden paper product as a vapor retarder, the warmth may cause it to off gas. If you are to install plywood over a solid, concrete subfloor, then I would consider a floating subfloor comprised of opposing 1/2" plywood panels glued and screwed together. First, you would flatten the concrete, then lay 8 mil polyethylene sheeting over the entire concrete subfloor, lapping seams by 12" and taping them. Then lay the plywood and glue and screw the panels together but NOT to the concrete. Over this, you could lay a solid floor and nail it with 1.5" fasteners. I would also glue it as well. This is a floating subfloor.

Just do not think you can lay down some solid flooring like you normally do. One needs to consider the heating system.

5" wide solid?? your going to be chasing that job forever!!

I would not put any solid over radiant heating.

Especially one of those dang exotics. What a recipe for disaster.
The only solid you should entertain for this type of install would be a 2 1/4 inch width quarter-sawn material.
Even engineered will move on a radiant heat system if the house does not have really good humidification system.
I like the dual layer plywood sub-floor for nailing purposes, but if you go engineered, I would be gluing the floor down.
The heating industry has done a wonderful job of promoting the new techology radiant heat systems, leaving us floor covering guys to come up with solutions for the client that still wants hardwood.

About 60-70 percent of our custom projects now include radiant heat systems in at least part of our work space. Fortunately, these clients also seem to have a penchant for 1/4 sawn white oak. (what a break for us)
I have also done 1/4 sawn walnut but man is that a boring look when finished. Almost any wood can be had in a quarter-sawn configuration, but it can run the job costs way up there.

I had a customer who wanted 3 " over radiant heat . I called the mill to see if they would stand behind the product ,and sent them a piece of the system . Their response was no way .

So Dennis, how is that working out? Does the solid quarter sawn wo strip perform well over the radiant? I figure, with the exception of a few, very stable woods, it would do well. But here in CA, we see little radiant so I have only done a few. All were engineered.

Works out very well, especially with 2 1/4. Have also had success with 3 1/4, but anything wider than that and its engineered or call someone else.
Remember that most of the expansion and contraction with quartersawn is vertically oriented so very little gapping between boards.