On Site Materials

Started by Squirl, April 16, 2013, 11:15:59 AM

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Squirl

I am a little fascinated with the concept of using on site materials for building a house.  Luckily New York has an exemption for grade stamped lumber.  This covers a large portion of what a house can be built out of.  The other thing I have found an abundance of is rocks.  Luckily with rubblestone foundations and walls, this can be used too.  Depending upon the site, there are a lot of options.  A person with enough time on his/her hands could build most of the house, minus utilities and appliances out of materials found right on the property and still be to code. 

I used to veer towards wood, but upon reading up on masonry, rubblestone has become more of an option.  A few provisions have help recently. 

First is I really enjoyed the masonry part of my build, more than framing.  Definitely more than roofing. 
Mass walls with continuous insulation can have less insulation and perform to the energy requirements of the building code.  Mass Wall R-value 15

http://energycode.pnl.gov/EnergyCodeReqs/index.jsp?state=New York

You can build a cavity into the wall for insulation, called a cavity wall. 



As long as it is tied, for design criteria, the thickness can be treated the same as a solid wall.

http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_6_par140.htm
QuoteFor cavity walls, the thickness shall be determined as the sum of the nominal thicknesses of the individual wythes.
QuoteThe minimum thickness of rough, random or coursed rubble stone masonry walls shall be 16 inches
http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_6_par124.htm

I've been kicking around a few ideas in my head.  I made a drawing of one for comments.  Any thoughts?


Don_P

#1
Love the idea, I've always wanted to do something similar running up to window sill height and the ntimber above. The footer is wider than it need be. If it were me and if that is a crawspace I's use a plywood form on the inside and make the wall the thickness of your corbel all the way up from the footing to the bottom of the sill. But either works, you can hand the rim from anchors for that matter and I would anchor the floor to the wall well. I'd want to insulate the inside of the below floor wall to keep it from sweating but it may not need it.

I dropped a white oak above the house today, to purchase the timber it could make would run into the hundreds of dollars. It is so disappointing to drive up to a jobsite and see great trees rotting or piled to burn and knowing I'll be going to the big box to buy crap. Another way to get good building rock is to talk to the dismantlers, folks that take houses down. One of our friends knows we, and especially my wife, has a real rock problem. I came home one day to find 5 truckloads of beautiful building stone, the foundation stones of a house they were tearing down. These were quarried and cut. He supplied me with a chimney of fieldstone for a log cabin restoration some time ago as well. The beauty of those is the pile was sorted by that first mason, it's generally useable rock.


UK4X4

You are missing an important part.

In brickwork you need a damp course to stop moisture being drawn up through the materials

In older construction slate was often used- in modern construction its a plastic membrane

this damp course needs to be above finished ground level and beneath your floor

ventilation to the under floor zone is also required .

Rising damp is the common name in the UK

It can be cured post build but its either expencive or time consuming.

One cure I used on an internal wall in my UK house was to drill holes in the wall slanted down apro 4" apart over the whole length of the effected wall

Install funnels in each hole

over a month keep pouring silicone oil into the funnels

This builds a silicone oil barrier to stop the water being drawn up through the materials

Plastering over it -mind you is a pain !

Squirl

Thanks for the tips.

I will start asking around.  I talked to a few quarry operators.  They love demolition concrete.  They charge the drivers to drop it off, then resell it.  Profit/Profit.  I was looking at bidding on one property at auction.  It had a stone foundation built and the rest of the house burned down.  Everyone was talking about the mobile home slab that was poured and I could bulldoze the old foundation.   ???
I love the idea of the already sorted and dressed stone.  What a find.

In many of my readings, I had not come across the damp course yet.  It is interesting.  Probably half the sites and some of the books I read on masonry have been British.  Much more of it there.  Less trees I guess.  I wonder if SBC can be used as an impermeable layer for mortar for damp proofing?

Around me there are a lot of old stone walls.  Many times the property lines have changed and they are in the way.  I have one that bisects my property.  It is about 200 ft long.  It would be something to keep an eye out for when I look at properties.


I was concerned about the footing.  I was calculating the weight of the wall at 150 pounds per cubic foot.  At 1.33 cubic feet per linear foot even a single story would have a 13 ft tall wall (3.3 foundation, 1.7 crawlspace, 8ft wall).  I was at 2600 lbs per linear foot before the floor and roof loads.  I was between 2 or 3 ft wide.  I went with 3.  Maybe it is a little wide.

MAXIMUM WALL LENGTH TO THICKNESS OR WALL HEIGHT TO THICKNESSa,b
Bearing walls:     
  Solid or solid grouted  20
  All other  18
http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_6_par135.htm

I am trying to determine which category the wall would fall into.  Not a big deal.  At minimum a 16" thick wall should be able to stretch 24 ft unsupported (16x18/12).  I've been kicking around a few floor plans.  The main idea so far has been a 30x40 with a cathedral roof above the kitchen, dining, and living area.  The other half would be the bedroom side with a spiral staircase up to an open library/office above.

UK4X4



stops rising damp- the older slate and tarpaper ones often fail in older properties



JRR

I would be concerned about the floor joist resting on a grout filled block.  I would prefer seeing a poured-in-place concrete detail with some steel rebar component tieing deeply into the wall.  Would take some engineering.

Squirl

I was thinking 8" hollow grouted concrete block for a few reasons. 
First they are uniform and easier to level.  I thought this would give me a chance create an easy even floor.  Next the sill plate must be attached to the foundation every 6 ft with a pt 2x4.  The 7" deep J-bolts seems like a bit of a ridiculous amount of overkill with a 18" thick wall in front of it, but I don't write the code.  I could put the bolts in between the mortar joints in between the blocks, or just use a hollow grout filled block for the bolt blocks and solid for the rest.
I wasn't as worried about the corbelling.  I went 8" because it would surpass the code requirements for corbelling.  ½ height is 4" projection, 1/3 thickness is 2.5".  Maybe I could run 12wx16lx8h block lengthwise.  ½ height is 4" projection, 1/3 thickness is 4"
http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_6_par129.htm
R606.3.2 Corbel projection.
QuoteThe maximum projection of one unit shall not exceed one-half the height of the unit or one-third the thickness at right angles to the wall. The maximum corbeled projection beyond the face of the wall shall not exceed:
1. One-half of the wall thickness for multiwythe walls bonded by mortar or grout and wall ties or masonry headers, or
2. One-half the wythe thickness for single wythe walls, masonry-bonded hollow walls, multiwythe walls with open collar joints and veneer walls.
I recently saw a few good illustrations in the AWC heavy timber guide.
http://www.awc.org/pdf/WCD5.pdf
Figure 8.
I am trying to find and use generally accepted practices rather than hanging the floor from the wall and having to use extensive calculations. 
I tried to draw a rock over top corbelled ledge that would serve at a head joint and run the full 12" of that wall thickness.  Maybe I should use a dimensional concrete block there and build the rest stone above that. Thanks for the discussion, it is helping with the design ideas.

I wanted to corbel it as little as possible and floor joists need 2" of  bearing.

Don_P

Take a look at the corbel reinforcement details for ICF's.

Squirl

#8
This is the best illustration of the code limits on corbelling.



It is also the basis for the code limitations.  As long as the angle of projection is less than 30 degrees the masonry will project the load to the below masonry.  This is the basis for the code provision.

http://www.gobrick.com/Portals/25/docs/Technical%20Notes/TN36A.pdf

Figure 9 has the best illustration I could find.  As long as the projection is less than 30 degrees the masonry will transfer the point axial and sheer stress to the course below.  No reinforcement required.



QuoteFig. 9 illustrates graphically the pattern of stresses within two corbels of different configurations under identical
loading conditions. The corbel on the left is 45 degrees from horizontal, which is not in accordance with building
code requirements. The corbeled wall on the right has an angle of corbel 60 degrees from horizontal and is very
close to the building code requirement of 63 degree 26 min discussed above. The 60 degree corbel shows a
stress pattern with axial and shear stresses with the only concentration of stresses directly below the applied load,
P. The shear stresses are well distributed within the wall section. The 45 degree corbel, on the other hand, has
bending stresses in addition to the axial and shear stresses, and the pattern of the stresses has been drastically
altered. In addition to the concentration of compressive stresses immediately beneath the load, P. there is another
concentration of compressive stress at the toe of the corbel. The bending stresses require that a corbel of this
configuration be rationally designed and reinforced. Those corbels having an angle from horizontal of 60 degree
or greater do not require reinforcement unless they exceed the other requirements given above.

If no one had asked, I would never have looked that up and learned it.


Don_P

 [cool]
Now there's how to do prebuild homework. Interesting, we use 45 degrees in woodwork , I've seen it used in soil and in masonry, footings and their support. The left pic shows the stress returns short of the support... very good info and graphic, need to think about if and how that might apply elsewhere.

UK4X4

Uk don't run any perimeter supports as such the joists are positioned on the inner wall and cemented in place-set on slate for levelling if required



Don_P

Is that current construction?
I think it would need some modification to pass here;
Treated sill on the masonry,  joist end lateral support,  hold downs,  gap between masonry and untreated, approved floor sheathing.

UK4X4

Going by the breeze blocks and particle board flooring thats pretty recent - mind you most houses in the UK are 100plus years old in my area- which would be true sized 1" with no T&G

No treated sills- with the damp course- there is no water in the interior brickwork- no water- no deterioration

By adding the sill you'd be adding a break point in the wall

Remember behind the wall you see is a 3-4" gap with insulation and the outer wall of the house which is continuous from ground to roof

we would have hold downs on the roof ceiling joists, but for a first floor its doubtfull

where would it go it has another story of bricks holding it down !

Mind you its been while since I've been on a UK site - so yep things may have changed

last floor I put in was nearly 20 years ago !

Squirl

That looks like every floor I've seen from the early 1900s, only stone and brick instead on concrete block.  Rough cut 3x lumber and all.  It is like seeing it new.



I was kicking around the idea.  I would love to use more onsite materials.  The less that has to be trucked in is part of the design goal.  I would just need to find a rock thick and wide enough to span the 2".  1" to each side would be 1/2 height x 2" 1/3 thickness or 6".  So a 3hx6Lx6W rock should be more than enough to create a joist pocket.

My concerns were like don had written.  Even with the damp course, it may be difficult to fly by and inspector.  With a damp course below and a solid foam layer towards the outside, there should be little moisture issues, but I am not a master mason and may have a difficult time convincing a third party. 

More of a personal skill concern, with uneven non dressed stone, it may be more difficult to keep the joists level.  It would probably just take some extra patience. Then again, if I had that much patience, I could probably hand chisel out the blocks for the corbelled ledge.

I've also seen a 2" racking, where they let in the wall and corbel out the rest of the wall over it.  I would rather rest the floor on a corbel than have a heavy wall corbelled. 
I always noticed angle cut to the joist in a racking pocket.  I wondered why this is.  It is called a fire cut joist.  If a fire burns through the joist support on one end, they can fall and leverage tilt the masonry wall out.  Ingenious.