Stone foundations

[bigmish]

Sounds like a concrete footing is a necessity for a house sized structure in colder area (I'm in upstate New York).

But I'm wondering, what about substituting a rubble trench for the footings, so to speak? That is to say, rubble trench up to ground level and then stone crawl space walls...

[slowzuki]

Bigmish,

That is basicly what we did.  Concrete can't take frost heaving any better than rocks, it will crack and break up.  You need 3 things for frost heave:
-freezing temps
-frost susceptible soil
-moisture/water

Railways built a high bed of non-frost susceptible soil to solve it.  Frost protected designs use insulation to prevent freezing of the soil.  Some other designs put a layer of vapour barrier and a porous layer before packing original soils back on top in layers, this is a moisture managed design.

BTW normally a building built in a bog won't heave, the water level in the soil is so high the ground doesn't freeze more than a few inches to a foot.

A rubble trench attacks two heave problems, it is a non frost susceptible material and it dries the ground out to help prevent heave in the soil around it.

[bigmish]

slowzuki, that's stone on the rubble in that photo? Looks like a poured slab. Or was this on a diffrent building?

[SwampDonkey]

We hauled field stone from several rock piles on the farm and built up a 4 foot layer of stone, with a layer of gravel on top, before pouring concrete. It was 20 years ago for a conset building. It's held up well and there has never been any heat in the building. It was just to store machinery out of the weather.

[slowzuki]

Sorry, in engineering terms stone is almost the same as unreinforced concrete.  Mine is indeed concrete.  Mine only really needed steel to fight the shrinkage cracking, but was speced by another engineer (not me, the building inspector wanted a structurals stamp) who did not recognize the performance of the rubble trench so it contains lots of steel.

slowzuki, that's stone on the rubble in that photo? Looks like a poured slab. Or was this on a diffrent building?

[MSU_Keith]

I'm considering a hybrid foundation:
- rubble trench topped with a poured concrete grade beam around parameter
- joists on top of grade beam creating crawl space
- poured concrete piers up to finished floor level for internal post supports

My thinking is this will save me money on poured concrete and parameter rubble trench will solve some water problems as mentioned.  Slowzuki: did you consider piers for your internal post support compared to rubble trench/grade beam down the center?

[slowzuki]

Keith, yes I did consider piers, but the escavator dug the trenches in about 1.5 hours instead of me having to sink piers.  I also considered piers to the trench but didn't have information on my bent spacing at the time of the foundation work. (Very bad idea by the way!)

The engineer I hired to stamp the drawings suggested piers all the way around but I wasn't at all keen on that.  I've tried sinking things in a line before for pole barns and it is darned hard to get square.

[Don P]

The masons are just about done on a stone retaining wall I thought was worth showing off. We call it a dry laid look, the mortar is held back from the faces wherever possible.

He did a nice job with the steps

One thing the present code doesn't address that I recall from dad's old book was bondstones. If I remember right it said that a stone needs to cross through the wall every 4square feet. Required or not its a good idea. Look at the third rock above the footing. 

I quizzed the mason and he's never had a request for a dry stack new foundation although he has repaired some. He pointed out that he has to bed anchor bolts 7 inches into the foundation nowadays and couldn't do that in a dry stack.

[SwampDonkey]

Looks really good to me. And that job is alot more work than one might think, no easy task.

[Raphael]

  That's a nice looking wall, we've done the same thing with the field stones facing our chimney.  Around here rocks are the number one agricultural product, always harvest a good crop every time you till.



I plan on dry laid stone for a number of accessory buildings but it won't make code for housing.  I've got tons of blasted ledge left over from setting my septic tank and pump chamber, plenty of rubble and stone to play with.  I thought of using some of the large rocks as a foundation on grade to display timberframes for sale on.

  The 'Alpaca shed' I plan on building in the field will have rubble trenches (sloping down to daylight) and oversize piers to handle a 100psf+ roof load.  Stone will get laid between the perimeter piers.

[SwampDonkey]

Nice work on the flu Raphael. I like that little stove to. Never seen one like that. Is it a pellet stove?

[bitternut]

Hey Raphael that is quite a substantial looking chimney. I see you have a stove just like mine. Well almost anyway, mine has black enamel trim not white.

Donkey that stove is a Petit Godin. I think they are made in France. They have a cast iron shaker grate, little ash pan and the top flips up also. You can burn coal or wood. Well what the heck, I will let Raphael tell you all about his.

Sure wish I had nice stone like that handy to use for projects.

[Raphael]

My Petit Godin was a gift from a customer or perhaps it was a bribe to take away misc. garage clutter.  :D
  Eventually it'll be my shop stove, it's very tight and has a significant mass of cast iron lining the firebox so once it get's hot it can really crank out the heat.  It functions best as a coal stove as the fire box is quite narrow, it'll hold a coal fire all night but wood small enough to fit the firebox burns up to fast or smothers.  It has a double flue arrangement, a small port directly opposite the stove pipe and a larger upper flue that drafts down through an additional iron element on the back of the stove.  In france it would be used as an apartment or parlor stove.
  Our chimney is wider than it needs to be on the first floor, mostly to get the thimble centered in the mass but also to add thermal mass and balance the stove that will be going there.  We have a restored 1860s 18" cylinder stove that stands nearly 7' to the top of the finial, the chimney won't look quite so large with that parked in front of it.

[SwampDonkey]

We have a restored 1860s 18" cylinder stove that stands nearly 7' to the top of the finial, the chimney won't look quite so large with that parked in front of it.

What you heat'n?  ;D

[Raphael]

We have a restored 1860s 18" cylinder stove that stands nearly 7' to the top of the finial, the chimney won't look quite so large with that parked in front of it.

What you heat'n?  ;D

~2000 square feet of house plus some outside air when the heat gets to high inside.  ;D

[scgargoyle]

I grew up in a c. 1790 center chimney cape near the shore in CT. The soil was sandy, and the foundation was dry laid granite, although there was some chinking above the ground to block the wind. The chimney stopped at the ground floor, and was supported by two stone piers, with solid logs between them. The rafters were just logs flattened on one surface (they still had a little bark on them) for the roofing boards. They were notched into each other and secured w/ a trenail. That house was straight and solid after 200 years! We had the clapboards replaced on the south side of the house, and underneath the house was planked w/ chestnut 32" wide, and over 20' long. The flooring was original random wide hardwoods, double planked, and old rope jammed in the seams. It was built and lived in by a whaling captain, and was a fascinating old house to grow up in!