Hello everyone. Let me first say Hapy New Year and here’s to a safe and prosperous 2007. My wife and I are renovating an 1888 house with forced hot air and baseboard heaters. The kitchen (about 216 sq. ft.) is above a crawlspace. Our intention is to remove the flooring and subfloor, repair/sister the joists where necessary, and to apply Warmboard under Ditra under slate tile. We have contacted Warmboard for pricing and more information, but thought we’d solicit advice here in the meantime. After a search of the archives, I find a few discussions of Warmboard but most are either dated (2000-2003) or centered in a different area of the country (PNW) so I wonder how close to what we’re in store for they are. Does anyone in New England have experience with local/regional distributors? What sort of sq.ft. price should we expect to pay for the sheets? We will be doing the work ourselves, tying in may occur next fall, and my wife is an architect, if any of these factors affect your advice.
Many Thanks,
Forrest W.
Edited 12/31/2006 3:43 pm ET by fgw2
Replies
As far as I know, Warmboard is approx. $5 per SF, but you'd have to get a price quote to really know. There are several products you can apply over an existing subfloor--ClimatePanel, RauPanel, Roth, etc.--rather than replacing the subfloor with WB. As far as I've been able to determine, WB is typically a new-construction product, while others are more suited for retrofit. You might be able to get some info at heatinghelp.com.
We will be removing the subfloor anyway...the crawlspace lies between two basements (original and addition) and we will be moving a bathroom and laundry room and having easy access to the crawlspace should be a nice luxury. Additionally, the idea of working on the joists and taking some bounce out of the old floor are actually kind of appealing because of the crawl space. So when the subfloor gets replaced, might as well glue and screw Warmboard...................right?
I have not installed Warmboard but we may on an upcoming house. It seems to be a widely accepted product but my radiant guy is not crazy about it for a couple of reasons.
First, the tube spacing is set and doesn't permit him to concentrate heating in areas where more is needed, such as in front of a large bank of windows. With gypcrete, he can run the tubing anywhere he wants. With some of the other over-the-subfloor systems there are options for spacing the tubing differently, although not with perfect flexibility. So, you live with their 12" centers and set your water temps accordingly.
Second, you deal with the WB folks to get parts that suit your needs. You need to determine things like manifold placement etc. Not a big deal but not as much onsite flexibility.
Third, at least in new construction, the tubing is often installed before the interior walls are framed (tubing actually goes under interior wall plates). This means the tubing is subject to damage during the rest of the project. Tubing embedded in gyp is also subject to damage. Other systems allow installation of the tubing much later in the process.
Fourth, from the framer's point of view, you need to incorporate the product into your process rather than just installing commodity subfloor. There will probably be some routing of special grooves to get the tubing where you want it. There will be no aluminum in those grooves you route.
Myself I probably want to do gypcrete but there are some drawbacks there also--heavier floor framing, possibility of water damage, possible difficulty tiling over it. Some of the other systems look good as well. All of these options are fairly pricey.
David, I agree with everything you said, but in his case he doesn't have to worry about many of the potential problems you listed.
I think Warmboard would be a much better product if they had grooves every 6" instead of 12". That would allow a lot more flexibility.
It is a good choice for remodeling jobs like his where floor height may be a concern.
Personally, I would never use it in new construction. I like concrete or light weight concrete.
Surprising comments. It doesn't seem like a retrofit product unless you are willing to remove the existing subfloor. Otherwise you get 1-1/8" of new height PLUS your finish floor. The various other products all look more suited to retrofit, and are more like 5/8" thick, and in smaller pieces. Warmboard only makes sense to me if you can lay down a lot of 4x8s without cutting.
It is a good choice for remodeling jobs like his where floor height may be a concern.
My comment was in reference to his situation. He already said he was tearing the subflooring out.
In such a case, Warmboard is the thinnest, easiest, best product to install in my opinion. It saves a lot on labor and you get a good heat transmitter.
I do not like it in new construction for many of the reasons you listed. I find the concrete systems to be much more comfortable and I can do it all myself with no delays.
Warmboard is a good product. As Dave said, somewhere around $5 sq.ft. It's thick ,so it makes for a sturdy floor under tile.
Remember, you should insulate heavily between the joists below it.
I would get the router bit & pattern kit because you will probably have to route several grooves in the board yourself to accomodate different situations.
Use pex-alum-pex tubing
Use PL Premium and screw and glue to the floor joists.
Use this opportunity to perfectly level your joists before installation of the Warmboard.
They have distribution centers in NY, so you shouldn't have trouble getting it.
File any rough edges if you route your own grooves.
If your home is not well insulated or has leaks, you may need supplemental heating in that area.
I'm sure you know that you have to provide lower temperature water to the Warmboard??
Have fun!!
I like staple up with 3/4 t&g ply with 1/2" PEX 8" OC fastened with copper plated plumbing straps 12" OC under the floor after all framing is complete. I know I live in NC but my tower room has twelve windows in it and heats fine with this situation with 130 degree water in the pipes. Insulate the bottom of this assembly well though.
I would be concerned about the metal straps on PEX in a staple-up system. There are plastic C-straps (and bushings for 1-3/8" holes) that are ideal for this, and you don't risk having the strap bite into the PEX as it expands and contracts. The ones I use are white/beige plastic and any plumbing supply will have them.
I got this idea from Dan Holohan's book "Hydronic Radiant Heating" (http://www.heatinghelp.com) it's been used in Colorado for years and we've been doing all our staple ups this way for years as well with no problems, The key though is to get good contact between the pipe and the floor so the plastic ones you are recommending sound good.
Years ago I had an inspector require that all metal clips on a PEX staple-up be removed and replaced with plastic. I don't know if he was quoting chaper and verse, or just had his own idea.
Here is an idea I saw at a radiant site, that may be worth considering, and it is certainly less material cost than Warmboard.
Since you will get full joist exposure when you demo, begin with cleating and insulation, then another row of cleating, to support between-joist decking, the decking surface down about 1.5" from joist tops.
Onto this decking goes PEX or PEX-AL-PEX tubing, and then either lightweight gypcrete fill or simple sand fill is used to pack and encase the tubing, creating a mass under the subfloor which is heated.
You know how gypcrete goes atop a subfloor. This is between-the-joistbays gypcrete below the subfloor.
Atop that, you simply have your plywood subfloor, then your Ditra and tile.
Since you will get full joist exposure when you demo, begin with cleating and insulation, then another row of cleating, to support between-joist decking, the decking surface down about 1.5" from joist tops.
We just did a job like this last fall. It worked great. You must have beefy floor joists tho'. This was a 100 year old mansion with 2 1/2" thick hemlock joists.
With a detail like that, I assume you run the PEX downhill at the end of each joist bay to avoid drilling too close to the top of the joists. To do this, you must have to drop down thru your "pan" somehow.
Yes, that was the problem. It wasn't bad in that situation because we had joists sitting on top of a support beam in the basement and simply stopped the concrete short of the wall and let the pex drop down and feed through holes in the joists where they sat on the beam.
The pex was fed just as you would do it if the tubing was under the floor.
It was a bit of work, but was a good solution to the situation in that home.
we looked at Warmboard , wound up with QuikTrak in a big sunroom job.. my heating sub supplied the board, we installed the board, he ran the pex and took care of the manifild & bolier hookup/ thermostats
applied 1/2" underlayment ply over that and then had our tile guy install the tile
whole system worked great... on it's way to the 2d winter.. owner loves it
here's a link
http://forums.taunton.com/tp-breaktime/messages?msg=63765.1
We're moving away from the Warmboard idea due to the cost and the total thickness under tile/thinset and Ditra. The QuikTrak idea is interesting; does anybody know the sq. ft. price for the boards? The other option is laying Pex on top of the subfloor (maybe over sheet aluminum), clamping it down with plastic clamps and pouring a mortar bed over that...too extreme a swing from Warmboard or am I on the right track?
You probably wouldn't use mortar, you'd use gypcrete and the cost would not be a lot less than Warmboard. It adds 1-1/2" of height over the subfloor and poses some issues re dead load and correctly setting tile. If you really need to keep the height down you either recess the tubing between the joists as described above, or just go with a staple-up system under the subfloor. That last one might be the easiest for a DIY to accomplish.
You can get some exact pricing for Uponor QuikTrac by googling around, buy my recollection is that it runs about $5 per square foot.
Edit: I wuz wrong and my memory needs rework. I just checked, and it can be bought online for $8 per 7" x 48" panel, so that works out to $3.43 per square foot, plus shipping. Then you need the loop end pieces, etc.
It is a highly efficient way to deliver heat to the floor, but if you are tiling over it, you will be first putting down a cement board layer. I think 1/4" Hardibacker would work for you.
Edited 1/3/2007 1:26 pm ET by Gene_Davis
If you use new 3/4" subfloor and any other type of wood track product on top of it you are going to be thicker than just using the Warmboard aren't you? Plus, you have two application processes to go through.
I think you should run the numbers again.
We just blew out our kitchen and adjacent storage spaces, including removing a dead chimney and several plumbing "ideas" from previous owners. A new subfloor was a must and radiators don't work into a kitchen very well. We used the Warmboard and an indirect kit designed to work with the warmboard.
It is an excellent system. Delivery requires a couple of extra hands dor DIY'ers. Cuts like regular plywood and is nice and stiff. We are really happy with it, and when the wife is happy...
Good luck on your job!
...that's not a mistake, it's rustic