# how do I build a house on blocks?



## Joe Carola (Apr 14, 2006)

farmer260 said:


> I am in eastern Canada and I am going to build a small house 20x36 (or so) this summer and I want it to sit on blocks like a mini home. I was thinking of useing hemlock beams sitting on concrete blocks or more hemlock. any thoughts?


Ask your building inspector that question.


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## farmer260 (Mar 22, 2011)

ok let me put it this way im building a shed not a house lol! i am building on a farm and I dont care if it gets inspected im never going to sell it and its just going to be a temp. "shed" anyway.


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## pyper (Jul 1, 2009)

The kind of construction you're talking about I've heard called "pier and beam."

It used to be typical in the South (USA).

I think I'd make a pole structure instead though. You need to get your foundation (piers, poles, or whatever) below the frost line. It's easier to put poles that deep than block piers.

Go to your local library and see if they have books on pole structures. My library has several. They include tables to help you size the beams and the poles.


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## farmer260 (Mar 22, 2011)

ya i know about that kind of construction I have done that kind of work for 7 years now. I am trying to build ontop of the ground so the "shed" can be moved someday.


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## Ron6519 (Mar 28, 2007)

farmer260 said:


> ya i know about that kind of construction I have done that kind of work for 7 years now. I am trying to build ontop of the ground so the "shed" can be moved someday.


You have the ability to move a 20'x36' building? You can still move a pole structure. Just cut the poles.
Ron


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## farmer260 (Mar 22, 2011)

yup I can move it no problem. I want to build on beams that sit on blocks im just not sure how yet. That way i can set the building down on the beams and slide it or put it on a trailer and move it. A building like that doesnt really weigh that much.


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## WillK (Aug 29, 2010)

My house in Michigan was built this way in 1917, 4 years before the city incorporated, and I think it's fair to say that it wasn't intended to be moved, nobody has actually tried to move it, but that has not stopped it from moving on its own anyway. Whenever I have spoken of how my house is constructed, it has always been as an example of what not to do. Monday I had an experienced concrete guy out to get a quote on a replacement driveway, and he couldn't be convinced that I have a house supported by blocks with no foundation until he actually got into the crawlspace and saw it for himself.

As I said, my house was built in 1917. It was balloon framed. There are 3 spread footungs under a central beam, floor joists rest on top of this beam and are butted at the center of the beam (no overlap as is typical current construction practice. Not a single floor joist under the first floor is original. Very few are not sistered. Very few of these new boards lack wood rot at the ends.

I must reiterate that this is not a good way to do things. The floor joists are supported by stacks of concrete blocks around the outside of the house and at various places between there and the center beam. These stacks have sunken into the sand. The presence of sand and the fact the crawlspace is heated have probably worked in the houses favor because the sand provides good drainage and the heat keeps the water in the sand from freezing.

With that said, the floor is crowning with a high spot at the center where the beam is sitting on some footings and low at the perimeter where there is no foundation under the cement blocks. The stairway is putting extra load causing an area of floor to be depressed, and a 3 to 4" sag in the beam supporting the second floor.

What I am doing to improve the situation is that I am adding beams at the perimeter and to replace the center beam (which has its own problems, such as being undersized and having joints that are not supported) These will be supported by 6x6 posts rigidly attached to the beam and spread footings. I am using plans from an engineer, and placement constraints are causing me to exceed the engineer's specifications by increasing the number of posts and beams I'm putting in.

My spread footings are not going to the frost line, later (3-4 years) I'll be having a footing put in for a foundation wall that will be below the frost line but that's not practical with my finances for now. I've gathered that because these are in conditioned (heated) space this is acceptable since the ground under them shouldn't be freezing.

Insulation should be on the crawlspace walls, not the floor above the crawlspace unless the crawlspace is open - but then again, if the space is open, then you'll have freezing under your support columns. And you'll have less defence against unwanted pests. Still, without a foundation wall, I can say from experience that rats can find their way in.


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## desiree_furman (Mar 31, 2011)

But I think it much better to build a small house than a shed....it makes you feel relax & comfortable than a shed..


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## Ron6519 (Mar 28, 2007)

desiree_furman said:


> But I think it much better to build a small house than a shed....it makes you feel relax & comfortable than a shed..


This makes no sense at all.
Ron


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## dtsman (Jan 1, 2011)

Set up your batten boards and strings and lay out your footers and pour to the frost line, then stack your block to level heights. I would use 3 or 4 - 20' beams, tie their ends together with what ever is appropriate for their size. Set the footers at each end and one in the middle of each beam.
Then lay your floor joist perpendicular on top of them. The size of the floor joist will depend on the number of beams. If you use 4 you can use 2x6 joist, if you use 3 you will need at least 2x8's.
Here is a link for joist spans for wood types.
http://www.awc.org/calculators/span/calc/timbercalcstyle.asp?species=Eastern+Hemlock-Tamarack&size=2x8&grade=No.+1&member=Floor+Joists&deflectionlimit=L%2F360&spacing=16&wet=No&incised=No&liveload=40&snowload=-1&deadload=10&submit=Calculate+Maximum+Horizontal+Span

Most important, flash the block before setting your beams so the wood doesn't set directly on concrete. It will absorb moisture from the block, and that part of the wood will stay wet and begin to crush. 
As mentioned before, common practice down here in the south but can be used anywhere.

If you know you are going to move it, install bracing in the beams and floor joist while you are building so you don't have to climb under there and do it later.

Bo

Remember,
If the women don't find you handsome,
they should at least find you handy. 
(Red Green)


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