40x70x16 shop

[bgibbons]

Well my dream shop begins. I will try and keep you updated and would love to have input along the way. I've never build a shop but here we go!! My first question would be

Is in floor heating worth it? I have been going back and forth on using a tankless water heater to accomplish this task. Lines would be filled with antifreeze and heater would be run off propane. I'm thinking someday down the road I could also use this tankless water heater to heat my water too if i ever decide to run water to shop. Is there a better system to use? I want to use the least power as possible since my power service will be around 100-125amps. Please see pictures of progress so far. I also don't need my shop to be more than 50-55 degrees. Thanks in advance

 

[mike93lx]

Tankless electric heaters require a ton of power. I think you'll run into problems with a pretty small service.

In floor heat is amazing and you only have one chance to get the pipe in the floor, so I would do it while you sort out how to run it

 

[loganb]

Will probably get proved wrong here, but have yet to see someone regret putting in the infloor heat... lots regret not doing it.

As mentioned, you can put the tubing and insulation(if desired) in now and the heating element later as that's figured out and cash is available

 

[velillen01]

If you can afford it, i would at least insulate and run the pex. You dont have to hook it up till you want...but you cant go back and add it later. Its an added up front expense but worth it IMO.

Especially since you look to be in Eastern, WA? Where it does get cold in the winters for longer periods of time

 

[Stuart in MN]

It's kind of late in the game to still be planning how to heat the place, if you're already under construction...
A tankless heater is a poor choice, particularly for a building that large. It sounds like you're thinking of an electric one, and they can require well over 100 amps all by themselves. A boiler designed for the purpose is what you want, if you decide to go with in floor heating.

 

[bgibbons]

It's kind of late in the game to still be planning how to heat the place, if you're already under construction...
A tankless heater is a poor choice, particularly for a building that large. It sounds like you're thinking of an electric one, and they can require well over 100 amps all by themselves. A boiler designed for the purpose is what you want, if you decide to go with in floor heating.

I'm build this shop at my pace so there is no pressure on how fast I need to complete it. I wont be doing the floor for quite some time so i've got time to figure out if I should do floor heat. I hope I'm not too late!! Other ideas for heating that you like?

 

[finn]

You probably need 200 amp service if planning for an electric boiler. Tankless water heaters are a poor choice over an electric boiler. They are usually highly restrictive so there is a high delta T and low flow compared to a boiler. A few may be dual rated for hot water or domestic heat.

I have in floor heat in my house and large shop. I installed the insulation and pex in my second garage/shop (32x54x13’) when I built it in about 2003, but never installed the boiler. Too expensive for what I use that shop for. I use a wood stove and 75000 BTU hanging propane heater.

I wouldn’t consider in floor heat if I ever built another shop or garage at this stage of life. Not worth the up front cost or lack of flexibility.

 

[rancherbill]

I love my in-floor heating. I would imagine a tankless would work, my system uses a "boiler" which to me looks like a tankless water heater. I think the difference is in the heat out put and the 'continuous' duty rating, but I am not an expert in any way. I use natural gas.

 

[Stuart in MN]

An important thing to remember about hydronic in-floor heat is that's pretty much meant to be on all the time, it can take quite a while to change the room temperature setting. You don't leave it turned off during the week and expect to be able to walk in Saturday morning and turn it up. If you use the shop on a daily basis it's a great way to go, but if you're only going to be in there occasionally and want to turn the heat off when you aren't there, a couple propane unit heaters would probably be better (unit heaters are the kind you see hanging up in the corner of a shop.)

 

[Jayman17]

That has to be eastern WA because we don’t have blue skies like that on the west side of the mountains.

Jay

 

[larry_g]

In E.Washington you should have enough sunny days to use solar to heat the water. The only electricity needed then is the power to run a circulating pump and a controller.

lg
no neat sig line

 

[bgibbons]

Tankless electric heaters require a ton of power. I think you'll run into problems with a pretty small service.

In floor heat is amazing and you only have one chance to get the pipe in the floor, so I would do it while you sort out how to run it

So i've been looking into tankless heaters that run off of Propane and require very little power to run. Am I missing something that I'm not thinking about?

 

[bgibbons]

An important thing to remember about hydronic in-floor heat is that's pretty much meant to be on all the time, it can take quite a while to change the room temperature setting. You don't leave it turned off during the week and expect to be able to walk in Saturday morning and turn it up. If you use the shop on a daily basis it's a great way to go, but if you're only going to be in there occasionally and want to turn the heat off when you aren't there, a couple propane unit heaters would probably be better (unit heaters are the kind you see hanging up in the corner of a shop.)

Those are some valid points to think about. I appreciate all the feedback. I plan to build a 20x35 workshop inside the building that will be used the most. Maybe I just heat that room. I plan to have an open bay for changing oils and working on vehicles but that won't get as much use. I have some thinking to do.

 

[bgibbons]

In E.Washington you should have enough sunny days to use solar to heat the water. The only electricity needed then is the power to run a circulating pump and a controller.

lg
no neat sig line

The winters around here are ok for the most part but a lot of times we get this soupy fog that settles in for long period of times which would be problematic for solar?

 

[bgibbons]

Today the foundation panels were pulled. The building is probably 6-8 weeks out so I will backfill and compact the ground in preparation for pouring the floor. Another question. Would I be fine with a 4'' slab for parking SUV'S and a camper or would you guys recommend a 5'' slab? If you think a 5'' slab is best please give me the reasons so I can weigh my options.

Also this building is going to be a clear span building that is build out of wood. Should be exciting, stay tuned!

 

[mike93lx]

So i've been looking into tankless heaters that run off of Propane and require very little power to run. Am I missing something that I'm not thinking about?

This is where details help a lot. All you mentioned was having 100a service. How could we know you want to use propane?

Aside from that, propane is a very expensive way to heat. Better than electric, in some parts of the country, but nowhere near the cost of natural gas

 

[kwb]

Heat Pump Water heater is another option that might work. Unless you need to keep it above freezing inside all the time having the heat on all the time is expensive compared to just firing up a unit heater when you are out there. It is 39F at my house right now. I got home from work, turned on the shop furnace to help dry some paint and it was 63F inside in a matter of about 20minutes. If I was out there all day every day as a part of my job or retired and looking to hide from the other half then keeping the heat on 24/7 might make sense. For the few nights and weekend days I get out there now.... the unit heater costs me very little to work in comfort.

Nice looking place and just a bit green with envy on the size.

 

[rburke65]

If you run the pet now, your **** is covered. If you want it it’s there and if you never use it you’re not out all that much money

 

[racecougar]

So i've been looking into tankless heaters that run off of Propane and require very little power to run. Am I missing something that I'm not thinking about?

How many BTU's and at what flow rate?

Today the foundation panels were pulled. The building is probably 6-8 weeks out so I will backfill and compact the ground in preparation for pouring the floor. Another question. Would I be fine with a 4'' slab for parking SUV'S and a camper or would you guys recommend a 5'' slab? If you think a 5'' slab is best please give me the reasons so I can weigh my options.

Also this building is going to be a clear span building that is build out of wood. Should be exciting, stay tuned!

What was the purpose behind excavating so wide for the foundation pour? That's a lot of disturbed earth you'll have to back fill and compact.

 

[finn]

Heat Pump Water heater is another option that might work. Unless you need to keep it above freezing inside all the time having the heat on all the time is expensive compared to just firing up a unit heater when you are out there. It is 39F at my house right now. I got home from work, turned on the shop furnace to help dry some paint and it was 63F inside in a matter of about 20minutes. If I was out there all day every day as a part of my job or retired and looking to hide from the other half then keeping the heat on 24/7 might make sense. For the few nights and weekend days I get out there now.... the unit heater costs me very little to work in comfort.

Nice looking place and just a bit green with envy on the size.

Using a heat pump water heater to space heat a room sounds like a perpetual motion machine.

 

[FMB4]

I'd forget in-floor heating on a shop that size. I-F heating is just way too much extra labor/material along with the added risk of too many issues in the future imo.

 

[bgibbons]

How many BTU's and at what flow rate?


What was the purpose behind excavating so wide for the foundation pour? That's a lot of disturbed earth you'll have to back fill and compact.

I'm waiting to hear back on all the exact specs for the system. As for the excavation my cement contractor asked for a 5ft wide hole to be able to work in. The footer is 12'' tall by 24'' wide.

 

[iamrfixit]

We built a shop for a friend in 2011-12. It's 50x104x14 with full concrete. We partitioned it right down the middle to make a 50x52 shop. That's a 2600 sq ft area, heated with radiant in the floor. We laid out 2" foam and stapled down 6 or 8 loops, can't remember for sure. Each was 250' long 5/8 tubing stapled directly to the foam, rebar over that on 2' centers and 6" of concrete on top. It works absolutely fantastic. Keeps the floor warm so any water or snow melt dries up fast. Anything you pull in warms up really quickly. He has several pieces of large equipment that we work on in the shop. They're very dense and heavy and take much longer to warm up in a shop with forced air.

It cost around $4000-5000 just for the foam insulation and tubing, we did all the labor. He runs a gas micro boiler that was approximately another $4500. It has some added features that a tankless wouldn't have, it monitors outdoor temp which is supposed to do a better job to anticipate heating demand. He could have added the tank and additional exchanger to heat his water, but it was actually cheaper to just install a separate tankless unit for water. His heating system is also filled with glycol.

A gas tankless has plenty of power to heat, and some are approved for use as a boiler. The tankless water heater in my house is a 199k btu condensing model that's approved to be used as a boiler. It can easily deliver 10gpm at 120F in winter. That's a 75-80 temp rise, much more than a heating system would require.

Ceiling height doesn't make a lot of difference with radiant, it's ideal for heating anything with tall ceilings. Unlike forced air heat, radiant is cooler up near the ceiling, the heat is kept down near the floor where you want it.

 

[Yankeefarmer]

Today the foundation panels were pulled. The building is probably 6-8 weeks out so I will backfill and compact the ground in preparation for pouring the floor. Another question. Would I be fine with a 4'' slab for parking SUV'S and a camper or would you guys recommend a 5'' slab? If you think a 5'' slab is best please give me the reasons so I can weigh my options.

Also this building is going to be a clear span building that is build out of wood. Should be exciting, stay tuned!

4“ tends to be the common thickness for a garage floor around here. The only reason I can see to go thicker is if 6th plan to install a lift. I went 5“ with mine because I planned a 4 post lift and that better satisfied the lift manufacturers’ recommendations than 4”. If you plan a 2 post you’d likely want thicker, but that’s normally only done at the post locations to control cost.

 

[bgibbons]

4“ tends to be the common thickness for a garage floor around here. The only reason I can see to go thicker is if 6th plan to install a lift. I went 5“ with mine because I planned a 4 post lift and that better satisfied the lift manufacturers’ recommendations than 4”. If you plan a 2 post you’d likely want thicker, but that’s normally only done at the post locations to control cost.

Thanks for the info. I think I'll just pour 5'' and be done with it.

 

[Kaizen]

I did 6" concrete and don't regret it a bit. yours is a lot bigger so consider it in areas you might want lifts. While you only need 4" i feel better with 6.
As i'm not in my shop a lot at one time..........example 3 hours after work.......i did not think it would be worth it to heat a slab so i did not put in pex or floor insulation. I regret it. I just did not have the money for the insulation which was imo a huge expense.

 

[Bennylava]

Will probably get proved wrong here, but have yet to see someone regret putting in the infloor heat... lots regret not doing it.

As mentioned, you can put the tubing and insulation(if desired) in now and the heating element later as that's figured out and cash is available

How much do you think the floor heating costs yearly? I'm already spending so much on my shop that if I don't really need something, it's probably best that I cut it.

s pretty much meant to be on all the time, it can take quite a while to change the room temperature setting. You don't leave it turned off during the week and expect to be able to walk in Saturday morning

What about just turning it on 24 hours before you plan on using the shop? Sometimes I go a month without using the shop, then other times I use it almost every day for a month.

 

[bgibbons]

Saturday I completed the back filling process. Winds were gusting around 50mph which wasn't much fun.

Do any of you guys use pellet stoves to heat your shops? I have thought more on heating my building after your feedback and since I wont be in my shop everyday I'm wondering if floor heat isn't the route I need. I really like the idea but if I'm not in the shop daily is it worth it?

 

[bgibbons]

I did 6" concrete and don't regret it a bit. yours is a lot bigger so consider it in areas you might want lifts. While you only need 4" i feel better with 6.
As i'm not in my shop a lot at one time..........example 3 hours after work.......i did not think it would be worth it to heat a slab so i did not put in pex or floor insulation. I regret it. I just did not have the money for the insulation which was imo a huge expense.

This is what has me torn Kaizen. I wont be using my shop daily so I just figured it was a lot of money to not utilize it. You now wish it was just heated all winter? How do you heat yours now? I can see myself regretting it later when i'm more financially stable and not so worried about all the minor costs as I do now at a young age.

 

[Yankeefarmer]

I chose not to put floor heat in mine, simply because I couldn’t ever envision being willing to incur the cost of heating the slab/shop 24/7 through the winter, or dealing with the complication of antifreeze if I decided to go a spell without running it. I have been in friends shops with floor heat and found them incredibly comfortable heat-wise, just decided I wouldn’t be willing to spend the money to make it worthwhile. As it is, I heat my shop with a 5 ton heat pump, and, contrary to what some folks here will tell you, find that setting it back to 45 deg when not in use works just fine. It heats to my target of 61 degrees in about an hour, and is comfortable then. Economically, it was the best choice for me and I have no regrets.

 

[Kaizen]

This is what has me torn Kaizen. I wont be using my shop daily so I just figured it was a lot of money to not utilize it. You now wish it was just heated all winter? How do you heat yours now? I can see myself regretting it later when i'm more financially stable and not so worried about all the minor costs as I do now at a young age.

I heat with a propane torpedo or trashcan type heater. If i had my ceiling done and insulated i'm sure it would be warm but right now it mostly goes out the vents or up above me. One other point is the time to heat a slab. You can't just go out and crank it up and be warm in an hour. it takes literally days to come up to temp and days to cool off. I have some in my house and i love it.
If you have the money i'd at least put it in for future use. Also i'd highly consider sectioning off areas in the garage. That way you can heat/cool 1000sq ft and leave the rest unheated for storage or whatever. So install pex in at least part or the whole thing but do it in sections so you can use or not use depending on what you need. I do like laying on my slab in the heat of summer lol

 

[Improved700]

Saturday I completed the back filling process. Winds were gusting around 50mph which wasn't much fun.

Do any of you guys use pellet stoves to heat your shops? I have thought more on heating my building after your feedback and since I wont be in my shop everyday I'm wondering if floor heat isn't the route I need. I really like the idea but if I'm not in the shop daily is it worth it?

I was going to heat mine with pellet or wood. I an in Northern Wisconsin.
Insurance agent told me they would not insure the shop, and would most likely drop my entire policy.
Since it is/was not our permanent living area, that was a hard stop, no go for them.

You may want to check first....

 

[pvanderlugt]

Had the same dilemma years ago, smaller shop, similar usage… was going radiant floor heat, ended up with a nice Reznor hanging heater and some fans… easier to change temperature from unoccupied 50 degrees to 65 short sleeve working on stuff, quick recovery time after opening the doors….I have worked in shops with radiant tube heaters, that would have been my first choice, if I had the ceiling height..the best of both worlds….. no doubt that a radiant floor heat is best if you are in there every day, but, if not, other options make more sense..

 

[dcg9381]

Tankless electric heaters require a ton of power. I think you'll run into problems with a pretty small service.

I use propane tankless heaters. I have no experience with them for radiant heating, but they've worked well otherwise.

 

[Diesel Dan]

Years back I seen a unheated shop floor being done.
It had vertical perimeter insulation along the walls and they laid one course of 4x8 insulation on the ground around the perimeter on the inside. Idea was keep the cold out of the slab but let the center stay in contact with constant earth temp that never freezes.
Never seen it in action but in theory sounds like it has potential.

 

[Novamania]

I am also located in Eastern WA on the Columbia River. Temps get into low 20's in the winter and low 100's in the summer. My existing shop is 66' x 48' with 14' ceiling. I just upgraded my system this last spring. I am using an electric forced air system with a heat pump, so I have A/C also. It has a wireless control so I can use my phone to control the temp wherever I am so prior to my arrival I set the desired temp. My electric bill for Jan. 2021 thru Nov. 2021 was $885. I also have a heated pool on this same meter that gets used May thru Sept. I keep the shop comfortable for me, usually low 60's during the winter. I am in the process of building a second shop that is 44' x 60' with a 12' x 30' bump out. It too will be heated the same way. Eastern WA has the lowest electric rates in the country. Take advantage of that. You can always add a wood or pellet stove if you wish. That being said, the in- floor heat is great but for me, not cost effective. I would also strongly recommend a minimum of 200 amp service. I have 400 amp at current shop and will have 400 amp at new shop also. You will not regret it if you go big.

 

[bgibbons]

I feel like I'm all over the board trying to figure out this shop heat source. I've been reading more about radiant tube heaters and I'm beginning to lean that way since my shop won't be used daily. How do you calculate your BTU needs to size it correctly?

 

[bgibbons]

3.5 days into framing the shop.

 

[brownbagg]

i wonder if you could do a fire pit outside to burn wood and have a coil and pump for your floor heat or even solar panels. i saw a diy one with copper coils on plywood and everything painted black

 

[mwalsh9152]

3.5 days into framing the shop.

what did you end up deciding on for heat?