Height Transitions Between Same Wood Flooring?

Hi All,

We are doing some remodeling, and we are looking into putting radiant floor heating under about half of our downstairs floors (which are all being ripped up anyway). The radiant floor is the kind that is basically plywood nailed onto the subfloor, with little grooves running through the plywood in which PEX is placed, with metal sheathing to direct the heat up.

This type of product adds about 0.75" to the height of the floor, so that when we put the real floor on top, there will be a 0.75" height difference between where there is radiant flooring and where there is just regular subfloor with no radiant flooring. All the top wood/engineered wood flooring we are using will be the same.

We have three transition spots:
1) between dinette area and a mudroom area (not a big deal);
2) between the front door area and a living room area; and
3) between the kitchen and a kids' playroom area (will be directly under sliding french doors).

Our builder/general contractor has recommended putting plywood down in all other areas so that it matches the height of the radiant floor areas - meaning there would be no transition areas. That would be more expensive than I would like, meaning the installer has said probably on the order of just over $10k to install (about 650 sq feet of radiant flooring, and maybe like 900 sq. feet of non-radiant - would probably mean we would not do the radiant floor heating.

I'm wondering how bad the transitions would look and if they would affect us during regular living.

I could easily do the additional plywood in the first transition because its very small (i.e., not too expensive).

What are people's thoughts on how a transition would be under interior French sliders? What about between the front door and living room?

Any other suggestions on what we can do?

Thanks for any help!

 

So how much for installing the plywood in the non radiant area?

A 3/4" transition is on the upper end, certainly between rooms with a door it might be some what hidden but in an open area I would try to avoid or minimize.

 

Thanks for the quick response.

I'm still waiting on him to run the numbers and give me a line item total.

The transition from the front door area to the living area is sort of a little bit of a hallway and looks transitional anyway. The transition from the dinette to the mudroom will be between areas that will visually look a bit separate anyway. Under the door will obviously look different.

I just don't know if all three will be problematic.

Also, any thoughts on using floating engineered wood instead of nailed-down hardwood? Are they half-way decent looking engineered wood products? My wife loves the idea of wood, so they'd have to be good enough to get her stamp of approval. I assume floating an engineered floor would be cheaper than having the flooring nailed down where the installer would need to be careful not to puncture the PEX. (Right?)

Thanks again!

 

I've personally only had/installed conventional 3/4 nailed down floor. I have never heard of any issues with engineered flooring so others would have to comment.

Your comment about the nail down is valid, conventional cleats are 1 1/2" long and easily go through the 3/4" sub flooring.

I think that would be enough to deter me from using nail down, one hit and everything would have to come up!

 

Quick-trak at Supplyhouse.com is a .5 inch product for radiant PEX underflooring.

I have used glue-down engineered flooring over PEX radiant. Check to make sure the flooring is approved for use over radiant. Not all are. If a manufacturer says their floating floor can be used over radiant that should be OK. You will certainly have to pay attention to clearances for expansion since the floor will be directly affected by the heat.

Do you have access to the floor from below? (Unfinished basement or crawlspace.) If you do then you could consider using a between-the-joists method to mount the PEX below the floor. See Joist-trak at Supply.com. I have used this in my dining room/kitchen area and it works very well through 3/4 inch solid subfloor with 3/4 inch hardwood finish floor.

 

Thanks again all, for all the advice.

Regarding the Quik-Trak product - I had looked into it, but I wasn't a big fan. Its metal/heat transfer plates are on the bottom of the product so that the product itself heats up. In contrast, both Warm Board and EcoWarm have the heat transfer plates on top of the product, in contact with the PEX.

Anyway, I just spoke with my contractor, and it looks like it would cost an additional $12k, all-in (including upgraded wood floors to handle heat, longer installation of wood floors over PEX to avoid punctures, extra plywood for raising subflooring in non-radiant parts, etc.).

So what do people think of this - I don't really need radiant floor for heating, the hot-water baseboards work very well (plus we have spent a lot of air sealing). Rather, I just want floors that feel warm when walking over them. We have a 3-4' tall crawlspace under everything. Its a poured concrete slab floor, and the crawlspace walls are all foam-spray insulated from the floor up to above the rim joists. In essence, my crawl space is a conditioned area.

What if we were to just drop a loop or two of baseboard heating into the crawlspace? Would that heat up the floors above the crawlsapce a bit so they would be nice to walk on? We have a very high efficiency boiler which is literally just feet away from the crawlspace. Would that work? My contractor is going to discuss with his plumber, but I'm thinking that may solve my problems.

Again, I just want warm floors, I don't need them to heat the house.

Thoughts?

 

Assuming that there is no insulation below the floor to isolate it from the crawlspace...Adding heat to the crawlspace will not make the floor noticeably warmer. It may be warmer than without heat but you could only tell by measuring the temperature of the floor. If you want the floor to FEEL warmer you need to heat it directly.

I have used the Quik-trak panels in two bathrooms. One has 1/4 inch cement board and 1/8 inch tile flooring. This is on the third floor and may have insulation in the ceiling below but not in contact with the subfloor.

The other has glued-down 3/8 inch engineered flooring. This is over an unheated basement and has 8 inch fiberglass insulation below the floor.

In both cases the floor gets comfortably warm even though the metal transfer plate is on the bottom and not in direct contact with the flooring material above. (The PEX tubing contacts the metal plate with heat transfer silicone caulk.)

As I mentioned earlier I have also used the under-joist method. That floor is over a basement that is heated only by the heating equipment and exposed piping. I installed 1 inch closed cell insulation board directly below the metal plates in each joist space.

Prior to installing the radiant for the dining area (specifically for the warm floor effect--existing radiation was not changed) I had also used some leftover Quik-trak panels between the joists under the floor in the work area of the kitchen with 8 inch fiberglass insulation below. In that area the metal plate is above the PEX and in direct contact with the wood subfloor above.

The kitchen and dining areas are on the same radiant loop and the warming of those floors is the same. The method of installation has not made a difference.

Finally, just to give you some more information about adding heat to the crawlspace--We have a heated 4-season greenhouse that is attached to our dining room through a sliding door. (It was an exterior door before and has double insulated glass.) It is 10 ft X 13 ft with 3 glass walls and a glass ceiling. The wall between the greenhouse is insulated. It was built on an existing deck with 4+ inch closed cell spray foam insulation below. On top of that I built a raised floor of 2x8s and plywood so there was space inside for fin tube heating below the floor. The raised floor is open at the ends so heat can rise up along the glass walls. There are 8 cavities with a 10 foot fin tube in each. The flooring is commercial carpet tile and rubber industrial floor tile. That floor also feels as warm as the PEX-heated floors but the amount of heat needed to achieve that is much more than the radiant.

Only adding heat to your crawlspace would not be uniformly effective for heating the floor enough to notice.

Since you asked on the DIY forum, would you consider taking the project on as DIY?

 

Hi John et al.,

Thanks again for the info.

Regarding heating the crawlspace - if the crawlspace got up to, e.g., 70 degrees (which is what we generally keep the house at in the winter), then wouldn't that heat the above floor up to at least 70 degrees? The heat would just need to transfer from the crawlspace, up through the subfloor and into the hardwood floor. (Right?) I guess I could put the crawlspace loops on a new zone and pump it up to maybe 80 or 85 degrees down in the crawlspace. We are not talking much cubic volume in that area anyway.

Regarding DIY - yes, I would definitely consider doing at least the crawlspace heating as a DIY (or, at least as a DIWEF - Do-It-With-Experienced-Friend). Does that count? (Why do you ask? Would there be a better way for me to do it if its DIY/DIWEF?)

Thanks again!

 

If done properly, adding heat to the crawlspace would make the floors above feel warmer but likely not as warm as the radiant, since it will likely provide a higher temperature. That said, the 'If' at the beginning of my response can be pretty big....

 

Hi Stick,

Thanks for the info.

I don't need it to be "radiant-warm" because I don't need to heat the house with it. I just want the floors to feel warmer than usual.

What are some of the factors that go into the "if done properly" at the beginning of your post?

Some of the things I can think of in our favor for it to work:
-high efficiency boiler;
-poured concrete floor;
-~R13 closed-cell foam spray on crawlspace walls up to rim joists;
-will not have any carpeting (just some area rugs); and
-low-height ceilings in crawl space, so small amount of cubic feet to heat up in crawlspace.

What other factors would go into it?

Thanks again.

 

There are two schools of thought with crawlspaces:
1. Insulate the ceiling, seal off from the house and open the space to outside air.
2. Insulate the walls, seal from outside air and open up to the conditioned air of the house.
Both methods include a continuous vapor barrier on the floor.

While the first method is common in the south, the second is the one more common in primarily heating areas and the one you would need for this to work.

 

Hi Stick,

I think we've already done the second option in your list. That is, we have closed-cell foam sprayed the walls of the crawlspace from the poured concrete floor up to the rim joists. Its 2" thick insulation, so approximately R-13. There is no insulation in the ceiling of the crawlspace, i.e., under the subfloor for the living area floors above.

Basically, the crawlspace is a conditioned space, and we are in the northeast (New Jersey, suburbs of New York City).

Is there anything else that would go into the "if done properly" part of your post?

Thanks again!

 

Since your original questions referenced talking with a contractor I just wanted to suggest that adding radiant heating under the floor after-the-fact was a possibility. Crawling around in a crawl space and installing metal panels, PEX and insulation is not complicated. Attaching to your heating system will take some skill but within the usual capabilities of DIYers.

Heating the entire crawl space could make the floor above feel "not cold" but it won't feel any warmer than the room it is in.

 

"Heating the entire crawl space could make the floor above feel 'not cold' but it won't feel any warmer than the room it is in."

I'd be ok with that! I guess if I cranked the heat up in the crawlspace to like 85 degrees, the living area floor might feel slightly warm. Good enough for me!

regarding DIY - I'm told I should probalby use quarter sawn hardwood flooring if I intend to install radiant floor heating (either now or in the future). So, I need to decide now if I want that type of hard wood installed. That's a question I'm debating with my wife now.

If we do decide to drop a heating loop into the crawlspace, any thoughts on what I can do to improve the results I'm looking for?

Thanks again!

 

You say the crawlspace is conditioned, which means there is heat and AC in there. Is that correct? If so, you've done everything you can.

 

Well, by "conditioned", I mean its considered part of the conditioned space. It is fully insulated/moisture-barriered against the outside has a direct connection (via air) to the rest of our house. I believe it is therefore considered part of the interior of the house envelope (if I'm using that term correctly).

What I want to do is put heating down there, as per your most recent post. We do not have any a/c down there, nor am I planning on putting it down there. (Its not really a space I like to go down in; its dark and only 3-4' tall, so mostly crawling around on hands-and-knees). I do have a dehumidifier down there that dumps into a sump-pump. Its not really needed ever since we closed-foam sprayed the walls, but it does kick on every so often in the summer.

I guess I have done everything I can, right?

Thanks!