ReplyYou suppliers sales engineer should be able to lay everything out. I would imagine you could do something with 5/16 or ⅜ pex. I never heard of ¼ radiant pex
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I think In February I’ll be redoing the kids bathroom. Since we spend the same amount of time in it as they do, I want my feet warm. Problem is we’re on a slab, so can’t use 1/2 inch pex then put my tile down as they would put me a considerable height above the adjoining floor.
The question is, would 1/4 in pipe work and provide enough heat for comfort only? The area that would be heated is 3’x12’. My thought was to run a 1/2” line then split it to 3 1/4” inch lines. Run each 1/4” loop 12” wide by the length of the room. Thoughts if it would provide any heat. I’m not a radiant guy.
Clearly the other option is electric, but I did that in my last house and even with a 220 feed it made the meter spin.
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You suppliers sales engineer should be able to lay everything out. I would imagine you could do something with 5/16 or ⅜ pex. I never heard of ¼ radiant pex
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Without insulation most of the heat will go into the earth under the slab!Originally Posted by jbhenergy
How thick is that slab? 10' X 10' area cuts real easy but is messy.
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Yeah 1/4” may not exist I honestly haven’t put a lick of research into it yet. Figured I would ask the brain trust here first before moving forward.
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X2,,,, now having a warmish foot(don't that feel good) is one thing and satisfying a heat load is another thing.
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In that situation I would:
Option 1 - cut the slab inside the bathroom walls into 12" square blocks and carry them out. Remove soil to about a 12" depth and tamp in a bed of crushed concrete. Lay on a sheet of EDPM as a vapor and put 4" of high quality foam board over it. Edge-drill the existing slab all around, install 1/2" rebar on 12" centers and tie all the 1/2" pex to the rebar grid. Then coat the edge of the old slab with concrete adhesive and pour the new floor. I would want to keep the new concrete wet for 28 days - but a week would be strong enough I imagine and/or you could use a high-early mix to shorten the cure time.
Option 2 - install a large vanity rather than a pedestal and build a 4" false-floor into the closet. Install three kick space heaters under the vanity (left, right, and center) and two under the closet. Direct one of them to heat under the tub. Supply them with boiler water as a separate zone or with a loop off the domestic water heater.
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
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Good lord Mikey I’m looking at 4 days not 4 months lol.
I realize under the heat should be insulated as I did on my last house and electric floor heat but I’m willing to absorb that loss in this case.
Now that you guys are making me think about this I figured I would have to look stuff up. 3/8 pex is 1/2 od so plus a bit of grout on top I’m probably looking at adding 5/8 to the floor thickness. I’m sure I can find some transition to adjust for that 5/8 thickness addition.
And since it’s really only for comfort during bath time and what not, I’ll eat that loss just for the pure comfort effect.
Hell maybe if the wife likes it enough I’ll get lucky the week after it’s installed.
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Get that agreement up front
Hell maybe if the wife likes it enough I’ll get lucky the week after it’s installed.
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How about radiant in the ceiling? You'll only lose 1 1/4"
If I do a job in 30 minutes it's because I spent 30 years learning how to do that in 30 minutes. You owe me for the years, not the minutes.
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You could saw cut/notch the existing slab and lose no height at all.
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
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I’m going for warm feet. Tile is cold in the winter on my old body.
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They make some slick attachments for angle grinders that all but eliminates the dust. I have thought of the option of doing that. Not ruled it out completely at this point.
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Just lay down electric infloor and only use it when you are in there. Put it on a timer so it's not left on.
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That's not how radiant works. If the sun was beating on the tile, would it be warm or cold?
If I do a job in 30 minutes it's because I spent 30 years learning how to do that in 30 minutes. You owe me for the years, not the minutes.
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Ill give you my "drinking my cowboy lost blues away" smart ass answer..... with my new windows I put in, the sun shinning in on the floor does not make much difference. BUT, in my font room, where I have a south facing 10x5 1964 window, when the sun shines on it, it is warmer than the floor in the next room over.
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A helper with a shop vac hose end in each hand will also work.
If you use long hoses the shop vacs can be outside / can discharge outside.
I fairly often use a water trap for dust: a five gallon plastic bucket with a lid. Two 2" male adapters through the lid - one with a stub extending to 3" above the bottom of the bucket as the inlet. The other one (outlet) just the lid fitting. Fill the bucket 1/3 with water.
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When faced with the choice between changing one's mind, and proving that there is no need to do so, most tend to get busy on the proof.
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ok....I FINALLY get to give an answer on something I really KNOW about. I have installed countless tile floors, and have put radiant heat in many of them. First off, without tearing the slab out and re-pouring it with the tubing in place it's pointless to even talk about using hot water to do it. Installing tile alone, on a slab, you need to assume 1/2" of rise. 1/4" for the mortar and 1/4" for the tile. Try to put tubing under that and now you are going to add AT LEAST another 3/4"-1". This makes the entry into the bathroom a tripping hazard, no mater what kind of transition you use.
The suggestion to grind the floor down is a GIANT mistake. Even with the nifty grinder attachments and a good shop vac (I have BOTH) you will wind up with dust EVERYWHERE in your house. Had to pay a maid service to clean a customer's house after we ground off the mortar, from previous tile, from the slab. And yes...we had bathroom sealed off with plastic, tape, etc...
My professional advice would be to use Schluter's DITRA XL uncoupling mat and SunTouch's "Warm Wire" kit. The DITRA is put on top of the slab with a very thin layer of mortar. Once that goes down the "Warm Wire" snaps into the mat. The tile then gets installed over that. Your total rise in floor thickness is approximately 3/4". Just keep in mind that you don't need to heat under the toilet or under the vanity, just where you are going to walk.
I won't go into any more installation details is this post, but if you have other questions feel free to ask. Happy to help in any way I can.
www.suntouch.com for the Warm Wire kits and any you can get the DITRA XL from a lot of different suppliers.
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I wouldn't go with electric. I haven't been around very long (50 years), but in my short time I have seen MANY electric heat cables fail. PEX tubing, when buried in concrete, has a 200+ year life expectancy. What happens when your heat wire fails?
I do like the idea of radiant ceiling. Remember, radiant heat heats the objects/surfaces in the room, no matter where the heat is coming from. Up above, down below or from the side. In fact, go with radiant walls and when you climb into the shower it will be like you're back in the womb!
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You heard the answer I received when I suggested it. Maybe you'll do better as you explained it better..
If I do a job in 30 minutes it's because I spent 30 years learning how to do that in 30 minutes. You owe me for the years, not the minutes.
Helpful Calcs, tips, tricks on my YouTube channel: https://www.youtube.com/channel/UCgm...TUTAdKmqRiTDEg
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Yes....I agree completely that circulating water is the BEST way to accomplish what he wants. BUT, as I stated in my first paragraph, it is pointless to even think about trying to add the tubing without tearing the slab out and re-pouring it.
I have also seen many electric systems fail, and in my experience I have found that in most cases the failure happens because it was not installed properly. Most commonly people try to heat the entire floor instead of just the traffic areas, or they place the wire paths too close together which overheats them. They put too much wire in too small an area. The kits come in 10 sq.ft., 20 sq.ft., 30 sq.ft., etc. and you need to get only what you need instead of rounding up. If you have 25 sq.ft. then you need to get the 20, and NOT the 30.
The other thing people get wrong about electric systems is the fact that they do NOT make the floor "warm". They are only designed to make the floor "not COLD". This is another reason they fail, the homeowner turns the thermostat all the way up and leaves it on all the time, which winds up burning the unit out trying to make the floor warm.
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