Hey again all. Thank you so much for the info in my last post, very helpful! Just wanted to get opinions in regards to the method of flooring installation I am considering. I have an undersubfloor radian heat system and am planning to install engineered hardwood in my house. Of course the best way is to nail the floor down, however I'm concerned with the nails puncturing the pex. Wondering if anyone has glued down hardwood over a undersubfloor radiant system or if you just did a floating floor? Thanks again

Under subfloor? Can you find where the subfloor is nailed to the joists, and match that with the hardwood?

Floating wood floor as much easier to later remove and howabout you come back and tell us how high the water temp is and how loud the snapple crack pop noise is after you get this monstrosity operating.

"Floating wood floor as much easier to later remove and howabout you come back and tell us how high the water temp is and how loud the snapple crack pop noise is after you get this monstrosity operating."

Very Helpful!

I would figure out a way to mark the top of the subfloor with the underfloor PEX runs. Warmboard stencils the bottom side of their panels with the tube locations to help keep someone from drilling up thru a tube run by accident...

Right, if you nail, just nail to the joists. Also identify the areas where the PEX passes thru the joists and don’t nail in these areas! My vote would be a thinner (i.e., lower R-value) engineered floating floor rated for HR. You will get better heat transfer and you will also be less likely to experience contraction/expansion joint cracking.

While condescending, Icfbound’s comment is not entirely without merit. Just Google “radiant floor heat noise” or “radiant heat expansion noise” and you will find hundreds of folks complaining about this. This problem is the result expansion and contraction of the PEX length within this sandwiched floor assembly which results in significant noise. The fact that these sandwiched floor assemblies also require a significantly higher water supply temperature results in even more expansion and contraction. This can sometimes be somewhat mitigated by running the system at a reduced temperature with constant circulation and using outdoor reset (ODR). Also be sure to only fasten the PEX using products that are approved by the PEX manufacturer. So, perhaps something to consider when first considering HR floor heating options.

By the way, this noise issue is not an issue when PEX is embedded in concrete. While the PEX still expands/contracts, it only does so in circumference by reducing/increasing the inside diameter. Incidentally, this is why copper pipe embedded in concrete ultimately suffers from fatigue failure. Copper pipe doesn’t handle cyclic circumference hoop stress well...PEX does.

Suurface mount sandwich systems like RHT Floor panel system will require about 100 degree h20 very similar to a topping pour
Staple up typically runs warmer think 125-135
Dan

Surface mount sandwich systems like RHT Floor panel system will require about 100 degree h20 very similar to a topping pour
Staple up typically runs warmer think 125-135
Dan

All this from an internet "Xpert" that has never designed, installed or serviced such a system, backed up by the condescending alter ego.

Too bad you don't have enough money to do it right!

Ticking is a function of the PEX tubing expanding linearly in a constricted space and suddenly "jumping" . And more common in retrofit applications, the sub-floor expanding and contracting over loose nail points-the same reason many wood floors crack underfoot. This is more common in a true "staple up" radiant system that may operate at 180F in an older loose house with high heat loads, but can be mitigated and even eliminated in the various "dry" radiant panel designs such as Warmboard, between floors and sub-floor systems following good practice following an experienced designer.

The many old copper radiant systems installed in concrete that we have replaced or repaired failed primarily from the outside but not from abrasion, rather their reaction to the alkalinity of the typical concrete mix and rarely if ever from friction since copper and steel have much lower coefficients of expansion.

As for floor coverings; the theory leans toward thinner "engineered" floors, but my theoretically perfect 3/8" engineered bamboo floors cupped at very moderate 80F surface temperatures and the 3/4" oak is still as tight and straight as the day I installed it in 2010. Fortunately my customers have had no problems with dozens of floor coverings save the occasional separation due to low indoor humidity levels.

Again, you may find a local contractor with real world experience or get a hold of BlueRidge for real DIY help.

If you wish to staple the PEX tubing to the sub-floor and pouring concrete or gypcrete over all, you will want to install 2x4 flat to the sub-floor as sleepers for nailing the finished floor as recommended by the flooring supplier. Honest people sell honest products all the time and most do it without slighting, snubbing or slandering others directly or through smarmy innuendo.

The problem is if you transfer the joist line locations by say snapping a line on top of the subfloor to indicate the centre of all joist runs, then you put the wood floor down and it covers those lines no? Btw I have a stapled up system with the aluminum plates. I'm just worried that one stray nail will damage my entire loop, then I'm screwed.

Others know better, but you can't just use nails short enough that they won't go all the way through the subfloor?

Today's glues are a marvel. I used Bostiks Best, a flexible one-part polyurethane, to glue down 3/4 oak planks. (Warmboard blesses BB as well a handful of other glues.) A year later, there isn't a squeak or pop anywhere. On the down side, my floors are Permanent with a capital P.

I would float engineered wood myself. Nailing is going to exacerbate footfall transmission to the floor below. Floating will attenuate noise. Make sure you have a vapor barrier between the finish and sub- floors. Dunno if engineered wood has it built in. If it doesn't there are products as thin as 2 mm that claim noise reduction as well as vapor control. Obviously, you will want to follow the instructions of the flooring manufacturer, which may or may not cover radiant heat.

Probably not. IMO flooring specialists don't know radiant, and radiant specialists don't know flooring.

Literate radiant heating specialists who have experience beyond cementious sub-floors should have a great deal of experience with various finished floor products. Infloor by Maxxon did the research and solicited the flooring industry for their input over 20 years ago.

Your average carpenter or Big Box flooring department employee, not so much.

http://www.homerwood.com/assets/Uploads/NWFA-Radiant-Heat-Install.pdf

http://www.healthyheating.com/Page%2055/hardwood1.htm#.V8gr5PkrJhE

http://www.hardwoodfloorsmag.com/installation/heat-wave-installing-wood-flooring-over-radiant-heating.html

http://www.warmboard.com/sites/default/files/pdfs/WB_InstallGuide_HW_1112.pdf

http://www.uponorpro.com/~/media/extranet/files/cdam/cdam_manual_7thed_0711_ch16.ashx?version=072920111126

Posted By Apollo1010 on 31 Aug 2016 07:35 PM
The problem is if you transfer the joist line locations by say snapping a line on top of the subfloor to indicate the centre of all joist runs, then you put the wood floor down and it covers those lines no? Btw I have a stapled up system with the aluminum plates. I'm just worried that one stray nail will damage my entire loop, then I'm screwed.

Welcome to the realities of above/below floor HR emitters. This is one of many reasons why many HR contractors don’t advocate or recommend these emitters. I am curious as to why you are not coordinating with and working directly with the company that sold you this system.

Can’t you transfer the joist locations to the wall area slightly above where the hardwood floor will be placed? If you are still not comfortable with being able to safely nail, this is just another reason to consider going with an engineered floating floor solution that is rated for HR. If you do end up with a noisy system, there are some recommendations that you may find useful here:

This Old House - Noisy Radiant Floor Heat