tar paper under oak floor and radiant heat

Dave Larsen_2

Surface temp means very little in this situation. The real worry is supply water temp. What is the heat load of the room? Even if this is only floor warming, where is the t stat located for the primary heat? I'd be a little careful about any high temperatures under that floor, maybe install a floor sensor. I've smelt tar paper on 2 different occasions thru my years. But I think that those temperatures were rather high. just use a bit of caution.

Jim_55

tar paper under oak floors and radiant heat

I have asked this question before and have gotten different answers so I am asking again so I can make a final decision . I have 15 Lb. tar paper under my floor and would like to know if installing under the floor radiant heat with pex a pex tubing create an odor/smell from the paper. My floor consists of 3/4 inch subfloor, 15 Lb.tar paper,1/4 luan,15 Lb.tar paper,3/4 inch solid oak floors-in that order. So there are two layers of tar paper under this floor. I allready have heat in the rooms and it works great but I am also looking to heat the wood floor for better comfort. I would use 85 F temperature for this application and the tubing will float under the subfloor. The dilema I have is that the article in the Hot Tech Topics says I will have odors for a long time and some one from this site said its OK if the water is 85 F. Before I go any further into this does anyone here on the wall have any opinions/advice concerning this matter. Thanks Jim

Chris_82

Not a clue as to smell, What do you mean "float"? Staple up jobs need, as a rule the transfer plates and insulation. Although I have found that they will work regardless of what people do. After installing a number of staple ups, about fifty over the last 15 years or so I imagine we have unknowingly heated a few flooors with tar paper in them, why contractors install tar paper is beyound me anyways, but never any complaints about smell, much more complants about buckling due to years of wax and floor finishis making the hardwood a solid unit.

Unknown

tar paper

sounds like you are only heating the floor for floor warming, max surface temp of 75F...

I've used tar paper in a lot of bathrooms.. a lot higher temp.. no smell.

Jim_55

BY float I mean the pex will not touch the subfloor and it will be be about 1 inch away . No transfer plates. Insulation underneath. And yes I'm looking to just warm the floor (75F) for a little extra comfort.

hr

The important temperature

is the one that is in direct contact with the paper. I have hundreds of systems installed under asphalt impregnated felt paper, aka roofing felt. It's not really a tar paper per say.

Flooring installers around here use felt paper on a regular basis, rarely do I se red rosin paper.

Only once on a very high temperature direct rubber tube staple up did we get an off gassing. And it did finally go away

In retrospect we really should never had to run the system at that elevated temperature.

If in doubt a plate system would reduce supply remperature requirements.

hot rod

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jim P._2

Thank you for all your advice. Dave- yes a floor sensor will be used and the supply temp will be low as I stated earlier. Hot Rod I think you were the one that answered this question for me a while back and thanks for replying again but when I read the article in the Hot Teck Topics concerning tar paper I became concerned about having the smell/odor in the house. From what I gather from everyones advice is that as long as I use low temps It will be OK to install radiant under this floor. Jim

hr

It would be nice to have a

definitive answer from the felt paper manufactures. Good project for the RPA!

I just started recieving Roofing Contractor mag, as my wife writes for them now. I'll see if I can contact some of the "paper" manufactures for their advice.

I suspect temperatures under shingles in the summer approch, or exceed radiant temperatures. There must be a temperature "number" available somewhere.

hot rod

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hr

felt paper PDF

The caution box at the bottom makes me think the manufacture would not embrace heating felt paper

I have a funny feeling they may indicate the product is not listed for heating applications?

I'll try and call their tech line Monday.

hot rod

jim P._2

According to the manufacturer they warn against heating this paper. I'back to "nixing" this project. Jim

Chris_82

out of curosity,...

I looked into my neighbors’ home which I was talked into doing a few years back. They have tar paper, linoleum, and a layer of tar glue, still very sticky, on top of the lino for the hardwood. Three of the worst smelling things you can possibly have. Because we didn't initially place transfer plates we bumped up the Wisbro, Uponhor, whatever their name is this week, we bumped up the tubing to 180, astute readers will notice this is above the recommended long term temp rating for the initial 3/8 tube. I warned the homeowner as to any consequences, and we did install some plates and some insulation, they use the under-floor as the sole source of heat, and 6 years later, the tube is a funky color, not the usual grey/white it generally turns into, this customer reports no smell ever! I am concerned about tube failure, but the homeowner isn't, his plan is to replace any leaks if and when they occur. The amazing thing is that we have about 25 runs off of three manifolds and all the tubing is tie wrapped in the 6-8 joist spaces under the kitchen without insulation in that part of the floor. The nice thing about not doing any calculations was that the plan to save cash was to just add more tubing if the initial wasn’t enough! The Wirsbro manifolds make this easy as we can just add on and add on, when and if needed. There isn't enough space to install insulation as each joist space has about 20 individual tubes leaving no room for insulation, additionally without doing anything that resembles a heat loss calculation, we wanted to heat the basement somewhat because the mod/con doesn’t throw much heat compared to the old boiler. Last heating season they report 1/2 the cost of the old unit and about 1/4 compared to similar abutting homes, a Btu is a Btu. O and it is also one of my primary loops serve the domestic 40 gallon SS and an individual 60 gallon storage tank, no controls, only the secondary runs thru the storage tank, all three zones controlled by a Taco zone controller. Independent of the boiler, no reset, no setback, this alone saved close to 2,000 in control and mixing valve costs, which was our objective to heat with radiant with out the associated cost gouging in costs. Yes we gambled and because I was close by with a willing homeowner to see what was going to happen, he now has a great system, although the kitchen cannot keep up the wife reports their only in the kitchen when the cook...the stove heats up the balance on these 6 degree days and isn't a big concern. Incidentally they report that the mod/con only cycles about 8 times during the last Saturday 18 degrees, they counted. Which I found hard to believe considering the heating storage tank was only set to 190. This may be because the upstairs 4 bedrooms and two baths are all INDIVIDUALLY zoned. When they need a room to heat up, all have individual tstats, the rooms heat very quickly, frequently in a matter of moments...And because the storage tanks are the thermal mass, just standing by so to speak the boiler duty cycle is markedly reduced. To those naysayer’s that we have a large standby loss just sitting there, the fuel bill says your wrong!

I'd go for it Jim!