I am in the process of “upgrading” my radiant floor by installing heat transfer plates in my staple up installation and replacing my existing carpet and rebond pad with a wood floor. I am going to install a floor sensor and am understand that I need to keep the floor temp at a max of 80-85 degrees and keep the relative humidity in the 40’s. My question is what to use for a floor. I am looking at a solid 5/8″ prefinished Teak alongside a prefinished engineered Teak or Asian Rosewood made by Bellefloor which is a 7-ply with a 1/8″ top saw veener. Basically staple or nail down vs. glue together and float the floor with the Bellefloor. Both floors are roughly 3.5″ wide and vary between 12″-48″ in length. My wife prefers the solid Teak and I know it would be a lot less work, but I am still a little concerned about movement with the radiant.
Has anyone ever installed either of these products over radiant? I have read the tests the Launstein.com has done with American woods and it seems like as long as the humidity and heat are kept in check, there is little movement. I am just trying to get as much input as possible before as this is a major investment and will be highly visable.
Thanks for anyones input or ideas.
Replies
Two years ago I used a Kahrs engineered floor over the same thing you have & am pretty happy. It was a new house & the floor floats. I did not dare to nail a floor down because of the wood movement. The floor strips are 8' long & snap together. The longest spans without an expansion strip were 40'. The building is 39'deep X 65' long and one story. I did not use the transfer plates around the pex tube - it is simply attached every 2-3' with clips and foil faced insulation installed with foil up. I am going to install an outside temp control to lower the water temp when possible.
I did find out later from Kahrs that there are 2 or 3 species that are not the best choices for radiant heat and beech was one & I found out after having it delivered and partially installed. Dispite this I have had no bad experiences with it. It has almost an eighth inch surface allowing a couple of sandings in years to come for the next guy. You won't miss a carpet. Wood never felt better. Good luck
Thanks for your reply on the Kahrs flooring. I was actually all set to go with their Rosewood until I found that it was out of stock all over until January at best. The other factor was the cost. My local flooring shops wanted over $7 sf. I found it on the Internet for less than $5 but Kahrs strongly discourages buying this way as getting warranty service requires either a flooring retailer or a company rep to inspect it first and buying over the Internet basically makes that unlikely. (I called Kahrs CS to question this). I really like their product and the interlock they use though. The best I found and definately less work than most the other floating systems which you end glueing together.
I found a solid 5/8 x 3.25 True Teak on sale last week for $4 sf locally and have been assured with careful monitoring of heat and humidity that it will work fine with radiant. Hopefully it will work as promised.
Thank you for input and experiences.
I'm up here in the NW corner of the lower 48 our humidity swings west of the cascades can be a terror on wood floors with radiant heat.
But on a "floating" floor I have not seen any problems. Only on the nailed down floors have I seen & heard problems.
Good idea with the sensor & yes a lower temp is a must. Remember the more consistent you can keep the temp & humidity the fewer problems that will arise.
Thanks for your post. I live in Central NH so we have probably similar weather conditions. What kind of problems have you seen with the solid floors? Was it due to low humidity and to high of heat or improper installations? I know some species are much more suspecible to problems as well. I plan on using a solid 5/8 x 3.25 True Teak with is reportedly very stable and has been using outdoors for flooring as well. I will be using a floor sensor and outdoor reset with a humidifer in the dry winters we have.
Time will tell.
Thanks again
Most of what I have sen problems with- is radiant added in a remodel with an old floor.
I helped my neighbor put radiant heat in under his 1941 red & white oak floor < which was common to mix them back then> I told him not to do it but he didn't like baseboards. Now he has squeak city.
High temps is big problem & just not to wood floors. When using radiant in floor heat you run a lot lower temps than baseboard or radiators.
& like someone else has posted it has been blown out of proportion.
When using hydronic heat you need to remember it's not fast it heats & cools slowly & evenly. Multiple setting thermostats are not recommended. You want to keep an even temp
Wood floors is like fine furniture- ever see a chair in a heated garage open & closing the garage door & BAM it splits.
I plan on using a solid 5/8 x 3.25 True Teak
You should be pretty safe with that we always joke about Teak not having any wood in it it's pure pitch. LoL
In my experience the question of wood floor movement over radiant heat has been blown out of proportion a little bit. I live in the finger lake region of New York, with pretty good temp and humidity swings. My 8 year old house has radiant floors with heat transfer plates under the 3/4 inch ply subfloor, and I installed wide plank {11"} t&g ponderosa pine floors, 3/4" thick in most of the first floor, with some random wide plank 3/4" thick rustic cherry in another area. We experienced about the same movement I would have expected in a conventional heated house, and most of that the first year. Floors stay fairly stable now. My boiler runs at about 115 degrees. Just my experience, but 8 years worth of observations.
Bish
Thanks for your reply. You seem to be doing well with a similar setup to what I plan. I live in Central NH so I have similar weather conditions. I will be installing Wirsbo Joist Traks to my existing staple up 1/2" PEX (2 lines per 16" bay) and have 9" of fiberglass insulation under this. I have a finished basement that normally stays about 50 degrees in winter.
I will be installing 5/8 x 3.25 solid True Teak with 1.5" T- nails to 3/4" T&G subfloor, so after seeing that you are seeing little movement with wide planks, I feel confident that this should work fine as long as I control the temp and humidity.
Thanks again
You might also want to dig back a bit to your original heat loss calculation (if one was done), to make sure that your tube spacing and loop lengths will support your need for a fairly low temperature application. Is the staple-up placed 2-per-joist bay? Is it 1/2" PEX or smaller diameter? How long is each loop? What was the problem with the carpet overlay? Are you making the upgrade simply because you want wood floors now or did you have a hard time keeping the room comfortable with the plate-less and carpeted system?
Just bringing this up because I'd hate to see you go to all the work of upgrading the system and still end up with inability to heat the space without roasting the fancy new flooring. If you need to shorten loops, add a loop to tighten up spacing, etc NOW is the time to do it.
That being said, I agree with the other poster saying that the problem with wood floors and radiant heat have been overblown...provided the system is designed so you can have both a comfortable room and a nice wood floor. And a signifigant portion of the design must be to keep your heat loss low through good insulation and sealing detail with low-heat loss window design.
Thanks for your reply. You had a lot of good questions. I live in Central NH so we do have some pretty cold weather. I have a very small house that I built in 2000 with good insulation and Anderson windows. I do not have a large heat loss and have been heating the whole house previously with a 30,000 BTU gas log stove although we don't expect it to heat the upstairs to 75.
I currently have 1/2" PEX running two tubes per 16" bay between TGI's over a finished basement with 9" of fiberglass (not foil faced) about 2" below the stapled up tubing. The radiant does work, but you can definitely feel the difference between the kitchen and the living room where the kitchen has lino and the LR has carpet with rebond padding. We want to change to hardwood flooring anyway and I expect that even without the heat transfer plates it would work better, but I want to be able to lower the water temp anyway. Right now it is running the same temp as the other two zones with baseboard heat (basement and top floor).
I know that I need to install the controls to temper the water and outdoor reset and floor sensors, but I think it will be worth it or it better be as it will require considerable labor on my part.
I really appreciate your time and thoughts.
Your wife is right, go with the solid teak you won't regret it the floor will feel much more solid than the floating one. To miniumize exspanion start in the middle of the room and install a double tongue and go out from both directions.
also acclimate the wood 2 weeks or so. The floor sensors are going to be a pain but go ahead. Make sure you don't put them in the path of sunlight,under furniture or throw rugs, in the traffic path (breezes & wind from room to room or an open door), or where the cat likes to lay down.
good luck
David
thanks for you input on this. Do you really think I need to start in the middle and go both ways with a 15' x 21' room size? I will have a very short 4' hallway into the kitchen (6'x 21') which will also be hardwood. What specifically makes the floor sensors such a pain?
Thanks again for your help.