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Radiant Floor Heating/Roth panel over slab - is there need for additional insulation?


We are considering Roth panels for radiant heated floor over slab for our 2 rooms, hallway and powder room. Is insulation provided by Roth panels with R value of 4.5 is enough? I would think at least R-10 is needed. Should we provide additional insulation under the panels? How can it be done? Should we add insulation to perimeter?
Also, for the floating floor there is no need for sleepers and the floor can be placed directly on Roth panels. Would it make soft feel to the floor? What should be done to avoid it?
Any other method for over slab would you suggest?

Badger Radiant Roth Ceilings
Badger Radiant Roth Ce  
We use Roth radiant panel for heating floors, walls and ceilings every day here in cold Minneapolis with great effect. The high density EPS backer and thick aluminum plate make the Roth panel one of our favorites for special applications where performance essential and space limited.

The insulation required on the cold side of any heating panel depends on how cold it is e.g. a four season porch exposed on all sides but one is a much greater challenge than a basement studio 8' deep.

As for a soft feel, the Roth panel sports a 60 psi insulation and will feel stiff but not soft depending on the size and gate of the stepper.

Naturally all is speculation until you secure a room-by-room Manual 'J' heat load performed on dedicated radiant floor software to determine if the Roth panel will meet the heat load.

We have used all of the current offerings for sub-floor, sandwich and poured floor radiant systems with perfectly acceptable results matching our clients' budget with product and performance but in every case we new the heat load before choosing the product, specifying the heat source and tuning the control system to the application.  

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Morgan M. Audetat


Radiant panel heating design, including floors and ceilings, European wall panels and snow melting for residential and light commercial buildings..............................................................-Master of Steam and Hot Water,City of Minneapolis....................................................--- Master Plumber, State of Minnesota...........


30 years..... Charter Board Member - Radiant Panel Association, former manufacturer of condensing boilers, former national distributor of radiant floor products, son and apprentice of mechanical & plumbing contractor. Current mechanical/plumbing contractor specializing in hydronic based, integrated HVAC systems. Radiant floor heating/cooling. Snow Melting. Condensing Boilers. Indirect water heaters. System design, consulting and technical training world-wide. Licensed contractor, designer, installer and consultant.

B.S. University WI 1981 CONTINUING EDUCATION: Viessmann Condensing boiler and Solar water heating certification 2010, N.D.S.U. Lead Worker RRP certification 2010, Knight condensing boiler certification 2009, Wrightsoft Manual J CAD certification 2009, RPA Designer & Installer Certification 2008, Nate Hydronic/Forced Air Certification 2008, Uponor/Wirsbo advanced design school certification 2007, Buderus Wall-hung certification 2007, Power Limited License (low voltage controls) 40 CE credits 2005, Basic Hydronic Certification IPEX & Northern Alberta Institute of Technology 1998, Charter Board Member - Radiant Panel Association 1994, Residential Off-Electric to Hydronic Conversion Heating School Canadian Hydronics Council 1994, B&G Little Red School House 1993, Rood Utilities (now Auburn Technical Institute) Oil Burner School 1993 ,Tekmar Controls residential and commercial 1993, Division Manager and Advanced Hydronic Seminar Instructor for the first Exclusively Hydronic Radiant Floor Distributor in the USA 1990, Hydronic Radiant Heating Association Workshop participant with Richard c. Bourne, PE spring 1988, Master Plumbing, Hydronic, Solar Course Red Rocks Community College 1987.

Awards and Honors
2009 System Showcase Award - Radiant Panel Association

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