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I’m almost through with my new bathroom on the 2nd floor of my 150 year old New Englander here in NH. I still havent put the tile flooring down yet, and I got the wacky idea that I could run 20 or 30 feet of flexible copper tubing through a channel routered out in an extra sheet of plywood on the floor. The tubing would be connected to the pipes in the next room that supply the hot water radiator.The purpose would be more to keep the tile floor warm rather than to heat the whole room. I have a gas fired hot water boiler that is pump circulated. Would it work?
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"Wacky." This may be one of clever ideas you regret later.
Get a little forced air heater. I put a toekick heater in our smallish bath, on its own circuit, and added a 120 V thermostat. The heat is fast and easy on a cold morning and keeps the mirrors clear.
*That loud sound that will, in the future, wake you and your lovely spouse in the wee hours of the morning? That sounds like, ahhh, gun play from the crack house down the street?No need to dial 911...it's just the tiles popping off your floor. When they pop, trust me, they "POP".The radiator water may be a bit hot to run under the tile. May. Maybe you could get away with it...maybe not. I doubt, though, that the high temp would be comfortable.Best bet would be an electric mat made specifically for the purpose. In a nutshell, it goes down in the thinset bed when laying your tile. Wire in a thermostat that can up the tile temp during the hours of the day you use the bath and you'll be in comfort-land.Good idea, I commend your attempt to come up with a solution to warm your toes, but I'd take a pass on it. The cost of the mat really isn't unreasonable, and the performance would be far superior to the copper pipe idea.
*I really like the idea of the mat, but lean towards the low tech toekick heater with just a 3-minute latency. I tend to be in and out of the bath quick in the morning, not lounging on the floor like they do in the ads (do people really do that?). Ah, then there's the horror of touching cold tile with your feet. God, people are getting soft! :)BTW, I wouldn't use a toekick heater anywhere else -- noisy!
*Andrew, The first winter we had RFH in my own house, my two kids would always lay on the floor, reading, drawing, whatever. My wife could never, ever, get them off the floor to sit in furniture.Funny part was they would both be crammed up agianst the wall of the living room, and would never, ever move either to the middle of the floor or up on the furniture. "We like it here" is all they'd say.The first time I joined them down there I figured it out...their "work area" sat right over the part of the floor where I had about 5 or 6 parallel runs of PEX, all running adjacent to the main beam of the house (over which sits the wall they slide up against), with the PEX runs heading out to their respective joist bays. Nice and toasty-warm.This past summer my wife claimed their area by placing a hutch there, so they've been displaced...their new area is, however, once again over a similar run of PEX.
*I say you should go ahead with your plan.Email me privately for some guidance or post it here on BreakTime.There are details which you should consider. But, what the hey, while you have it open.....why not try it?Jeffieps: I can show you how to do it!! Screw mongo and fred, they have grown complacent in the luxury[g].
*I'm with Jeff. Nothing beats the erie warmth of in floor heat. You might just find yourself lounging on the floor yourself some day.But there's also some good advice on the temperatures. Depending on what's flowing through your house now, it's going to be difficult or extremely difficult. You can't just circulate 150 degree heat through the floor. At least you're not working with steam, so it's not impossible. It's not that expensive to bed heating pipe in a floor. I would give it some thought and lay down pipe just in case, no matter which way you go.
*Will the tiles go in a mud base? I wouldn't ever put copper pipe in anything resembling cement, as it is corrosive. PEX tubing is made for this purpose, and meant to work with much lower temperature water. We have radiant floor heat in 3 rooms with tile floors. All were put down with PEX in mud base under the ceramic tile, and all give excellent comfort with just warm water...
*My grandfather's house (slab on grade-3200 sf) and his shop (6300 sf) has copper in floor heat. He has never had the first problem. Both were built in 1948. Rather than lay off his construction crew for the winter, he decided to build the home and shop so they would have work.He spared no expense. They knew better than to use flyash in their concrete that had copper or steel tubing. According to him, the use of flyash was the greatest single factor in concrete/copper failures. Next reason for failure was the practice of using long straight runs.My uncle has a slew of pictures that were taken during construction. I'll see if I can have him round them up for posting here on the forumn.My, how construction times have changed. These guys, pipefitters, plumbers, plasterers even wore white shirts and bowties to work. If a man showed up at work without a tie or bowtie, they were sent home for the day. The second time it happened, he forced them into early retirement.BTW, all of the ceilings in the house have copper tubing embedded (6 inch centers) in sand/cement/lime plaster. He was the extravagant type. He heated for about 25 years using methane gas from a homebuilt digester. He switched over to natural gas when he quit farming. Pigs are good for something more than Canadian Bacon.
*A dyslexic plumber I was chatting with a while ago (irrelevant story) suggested embedding PEX in the floor and runny the shower hot water supply through it. He also said I could set up a valve arrangment to switch the water diverted to the PEX to the cold line during the summer. i imagine this might even have a pleasant effect, or in a humid house cause gross floor sweat.Mongo, funny about your floor-bound kids (pets?). But I was really talking about pictures of people lounging on their BATHROOM floor -- some mfr ad in FHB. We have a serious defect in our forced air system -- the main register in the living room keeps getting stopped up by our 20-lb. cat, who parks his fat bod there with his fur flying in the breeze every chance he gets. I keep warning him he'd make an awful nice winter hat.All these tales of radiant floor heat do tempt me, and i even have some of most of the floors accessible at the moment ... but we have a perfectly good forced-air furnace. A hybrid system of radiant and forced-air might be nice -- a quick burst of forced-air heat in the weekday morning to get you out the door, then a longer run of radiant heat when you're home a lot.
*P -You don't mention what material the adjacent hot water radiator and other radiators on the system are made of. If it's cast iron and you add a copper loop you may be in for some very interesting chemical reactions (galvanic) below the floor. It could turn out to be a shower in the foyer below.PEX or better yet PEX-AL-PEX (Aluminum tube, PEX liner, PEX external covering) does not have the same issue. The electric mat is a fine idea too.I usually regret my wacky ideas ...Jeff C.
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Thanks for all the postings and the feedback.
Here are answers to some of the questions posed..the radiators throughout the house are cast iron. I was planning on putting the tile on top of the plywood using thinset made for plywood.
Do all plumbing supply stores sell pex? What;'s the best way to connect to steel pipe.?
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Mongo,
I'm with you on the radiant mat idea. I've got samples of this stuff at home. It looks virtually indestructable, can be set by a timer, is fairly energy efficient and doesn't cost a whole lot for a bathroom size installation. Why anyone would even consider cobbling together a system that has so much potential for disaster is beyond me. Not to mention the possibility of compromising an existing major mechanical system. Whatever . . .
EB
*Shop around for your Pex. For the DIY, places like Home Depot are probably cheapest. Plumbing outlets usually require you to be a plumber. Otherwise, you get the 3 times "off the street" price. Believe me, you don't want to pay those prices. I'm lucky in that the only real boiler/RF heat distributer in town is very much DIY friendly. They sell pipe by the foot (you take a roll home and return what's left) and have several tool boxes that they lend out free with all the crimping tools. All at prices between retail and wholesale plus all the free advice I can bother them for.One more important thing, you need to get the pex with an oxygen diffusion barrier. You may not be able to find this kind of pipe at the local HD. In a nutshell, plastic pipe allows oxygen into the circulating system, which then goes on to corrode (rust) anything made of iron (like those radiators for instance). Somebody mentioned PEX-AL-PEX. The purpose of the aluminum is to keep oxygen from passing through the plastic. The Rehau brand I use has a special red coating of some sort which serves the same purpose. Regular water plumbing pex doesn't care about disolved oxygen, because the fresh tap water is constantly providing a much larger source of disolved oxygen so there's no point.Pex connectors come in a huge selection of fittings. Threaded, solder, reducers, enlargers, mini valves, tees, etc. You can choose the crimp type fittings and crimp the pipe permanently, or use the twist on type fittings which can be dismantled a few times (not recommended). I've used both without problems.
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I'm almost through with my new bathroom on the 2nd floor of my 150 year old New Englander here in NH. I still havent put the tile flooring down yet, and I got the wacky idea that I could run 20 or 30 feet of flexible copper tubing through a channel routered out in an extra sheet of plywood on the floor. The tubing would be connected to the pipes in the next room that supply the hot water radiator.The purpose would be more to keep the tile floor warm rather than to heat the whole room. I have a gas fired hot water boiler that is pump circulated. Would it work?