Cement Pad?

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Dabster13

Member
Nov 27, 2018
74
MA
How many people aren't using cement pads for their boiler? Was thinking of going with a 4"-6" gravel pad with cinderblocks under each leg of the Heatmaster G4000.

Is the cement pad more of a luxury? Just wondering what everyones thoughts are on this.
 
I highly recommend pouring at least a 4x4 pad, my pad is 4x8. I'm in the middle of an install myself and wish I would of already poured a 6x8 pad. IMHO - your pad can't be big enough. My boiler will eventually be in a building so that's why I thought a smaller pad would be okay. Live and learn.

FYI - the Menards concrete bag estimator was about spot on for the number of bags I needed to pour mine.

[Hearth.com] Cement Pad?
 
Assuming you are asking about an outdoor boiler, it really depends on the underlying soils. If you are on well drained gravel, pouring a pad is usually not an issue but if you are on clay soils that can heave a potentially warm pad surrounded by frozen soil can be a big issue as in the spring things can sink and heave. I would recommend at minimum, strip out the topsoil, put down some geotextile and a layer of 6" of crushed rock under the new pad. The geotextile keeps the underlying soil from working into the crushed rock and the crushed rock keeps the area drained and can compensate for frost issues. Pay extra for steel mesh in the pad and add polypro fibers in with the concrete. If you are pouring a pad make it bigger than you think you want. I would pour a big apron out front as its going to get muddy throwing wood into the boiler in spring conditions.
 
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Assuming you are asking about an outdoor boiler, it really depends on the underlying soils. If you are on well drained gravel, pouring a pad is usually not an issue but if you are on clay soils that can heave a potentially warm pad surrounded by frozen soil can be a big issue as in the spring things can sink and heave. I would recommend at minimum, strip out the topsoil, put down some geotextile and a layer of 6" of crushed rock under the new pad. The geotextile keeps the underlying soil from working into the crushed rock and the crushed rock keeps the area drained and can compensate for frost issues. Pay extra for steel mesh in the pad and add polypro fibers in with the concrete. If you are pouring a pad make it bigger than you think you want. I would pour a big apron out front as its going to get muddy throwing wood into the boiler in spring conditions.
I'm actually likely going to be on top of ledge, trying to find a flat enough area to put
 
If you are on ledge then some gravel and blocks would probably work...just make sure the feet are sitting right on the web (center) of the block...there is some real weight there when full of water n wood...
 
If you are on ledge then some gravel and blocks would probably work...just make sure the feet are sitting right on the web (center) of the block...there is some real weight there when full of water n wood...
Yea, i did actually google the weight limit of cinder blocks (1700 PSI) and the weight of the G4000 + water should be about 2400 pounds, which will equate to 600ish pounds per leg.
 
Yea, i did actually google the weight limit of cinder blocks (1700 PSI) and the weight of the G4000 + water should be about 2400 pounds, which will equate to 600ish pounds per leg.
Yeah the block will support it for sure...but I personally still wouldn't want a boiler leg sitting right on the hollow core part of the block, they are not meant to take a load like that...meant to take load vertically, but you wouldn't want to use the block like that, in its "normal" position, since it would more easily sink into the ground/gravel over time...but I guess I'm making the assumption you were planning on laying the block on its side for this...
 
Just use solid block then
 
Just use solid block then
Or an even better option, a cement pad. A pad 8' long gets you out of the mud during the shoulder seasons when the ground isn't frozen. You can kill two birds with one stone. ;)
 
Or an even better option, a cement pad. A pad 8' long gets you out of the mud during the shoulder seasons when the ground isn't frozen. You can kill two birds with one stone. ;)
Or even better put your stove inside. Lol
 
@bholler and @sloeffle I would love to get my Polar in my garage, if ya'll are up to the task I'd buy some brews and you can help, lol. I am in the same predicament as the OP to a degree, I think I might just pour a pad and poke the loading door of the boiler through the garage wall so I don't have to build an enclosure but can at the same time be out of the weather to tend to it.
 
Except that you are heating the outdoors with the boiler, its not a bad idea to feed it through a hole in the wall but not sure if fire code allows it.
 
Except that you are heating the outdoors with the boiler, its not a bad idea to feed it through a hole in the wall but not sure if fire code allows it.
A G4000 is UL rated to be installed indoors. Mine will be going into a barn next year.
 
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@peakbagger I don't have to worry about that, building is not insured anyway, not with the premium really, the insulation on the boiler is pretty good so not a lot of loss, the bigger issue is it really fit into the garage, sorta but really touchy, so the poked in theory is better than just outside like it has been since march, set it quick to get it fired and tested out. I am hoping to get my shoulder healed up enough to work on things soon, just had it fixed a week ago, so no big chores yet. I am ok with it outside like it is but the wife was complaining that she didn't want to load it this winter if she had to be outside, so the poked through theory is the easiest and most cost effective compromise I have, I can always add an enclosure for the main body later as time and funds permit.
 
I'm actually likely going to be on top of ledge, trying to find a flat enough area to put
Out of curiosity, how do you plan on putting your electric and lines in if you are on top of ledge. Can you dig through it with a backhoe ?
 
As a point of interest and you can use this for other applications. I noticed a recommendation of using block and that it might be weak at the center hollow two sections. What I did with an 8"X8"16" blocks (to add weight) in my creek bed to prevent soil erosion was to fill the two holes with "Quickcrete" from Home Depot. My only purpose was to add weight so that I don't have the blocks washed downstream during a heavy rainstorm. Here's the specs:

Block Empty = 32.5 lbs
Block Filled with concrete =65 lbs.

John M

P.S. I am confident with the concrete filled blocks, there won't be any issue of them breaking/cracking
 
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As a point of interest and you can use this for other applications. I noticed a recommendation of using block and that it might be weak at the center hollow two sections. What I did with an 8"X8"16" blocks (to add weight) in my creek bed to prevent soil erosion was to fill the two holes with "Quickcrete" from Home Depot. My only purpose was to add weight so that I don't have the blocks washed downstream during a heavy rainstorm. Here's the specs:

Block Empty = 32.5 lbs
Block Filled with concrete =65 lbs.

John M

P.S. I am confident with the concrete filled blocks, there won't be any issue of them breaking/cracking
You can also just buy solid block already made
 
You can also just buy solid block already made
Or as @sloeffle mentioned, just pour a pad...which I think I'd lean toward, even on ledge...probably pretty hard to get a nice level spot made for the OWB to sit on when dealing with ledge anyways...and those OWBs want a level pad to sit on...often have to shim the feet to get them all 4 sitting flat, even on concrete.
 
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Or as @sloeffle mentioned, just pour a pad...which I think I'd lean toward, even on ledge...probably pretty hard to get a nice level spot made for the OWB to sit on when dealing with ledge anyways...and those OWBs want a level pad to sit on...often have to shim the feet to get them all 4 sitting flat, even on concrete.
Oh I don't disagree at all
 
I've had OWBs since the early 90's. First one, I poured an extended height pad and it worked out great. Until the OWB was removed.....then there was that dang "hi-rise" concrete pad in the yard. Quick side note of raising the OWB, the higher you go with it, the higher you have to lift those huge chunks of firewood to put into it. Not so much fun when it is -40f!!!

The next two (at different addresses) were on a gravel base and patio blocks. I think those blocks were 18" square and not quite 2" thick. I thought the whole system would settle over the years but there was not enough to mention.....maybe- maybe and inch over 14 years.

Now, the days of OWB are over. I am back to hauling firewood into the basement. (New residence) Which equates to handling the firewood three more times than necessary compared to an OWB.....and the mess is inside, not outside where it should be!

But, when the OWB does get removed from the yard where it is at, there is only the clean up of four pads (or blocks if you go that route) and a bit of gravel.