How to attach wooden floor to block basement

[rep...@workshop.com]

In the old days, I know that when they built a concrete block basement,
the wooden floor joists were just set on top of the block walls, and
they would make the top row of block with a solid topped block (no
exposed core). Then after the wooden joists were set in place, they
would put a thick bead of mortar on the inside, on top of the block
wall.

I've lived in several homes built in this manner. I guess they figured
the weight of the house would hold it in place, and that mortar bead
added to this, as well as keeping air from leaking and insects and
rodents from entering.

The problem with that concept is that if a tornado or hurricane hits the
area, it dont take much to knock the house off the foundation.

I'm planning to build a small summer cabin. It will be set on a
concrete block foundation, either as a crawl space, or possibly a usable
basement depending on cost. Since the cabin will be small, that would
mean is weighs less, and thus would probably make it blow off the
foundation easier. This is not an area that gets hurricanes, but
tornados are always a possibility.

My question is what's a better method to attach the house floor to the
block walls?
On: http://www.doityourself.com/stry/h2layconcreteblock
They suggest putting an anchor bolt every 3' to 4' in the last (top) run
of the blocks. I guess that would mean having an open cored block every
3rd or 4th block, and filling the block core with concrete to hold that
anchor. But that brings up two questions.

1. Filling a block's core generally means all the cores below it would
need to get filled, and thaT would take a lot of concrete. Unless a wad
of newspaper or some insulation is crammed in the blocks in the row
below the top one first.

2. Using floor joists laid on their narrow edge (such as 2x8's), this
anchor would end up with no wood to attach to, unless a 2x8 was laid
flat first, and then the floor joists laid on top of that, which is not
something I've seen. (Or is there some sort of bracket made for this
use?).

Then too, making sure these anchors dont und up directly under a joist
might be tricky too, because the location of each joist would have to be
measured and marked on the blocks first.

Anyone have any tips?

Please, if you want to tell me to contact a building inspector, or hire
a professional, dont even reply. This is a DIY project in a rural area.
There wont be any professionals involved, nor any inspections, other
than getting a building permit (to keep the local officials happy and
wealthy). I already inquired, they said that as long as it's not a full
time home, I just need a permit to build, and they need to know the size
and type of construction. (so they can raise my property taxes to suit
the structure).

[dadiOH]

1. "J" bolts in the block

2. 2x8 on edge through drilled to fit over the J bolts, nut and fender
washer

3. nail on hangers on the 2x8s for the horizontal sticks


--

dadiOH
____________________________

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[tra...@optonline.net]

I've never done this, but is the mortar going to fill more than just
the top block? The blocks are staggered, reducing the openings.
I would think the mortar would probably stick and bind up enough
so that only the top block winds up getting filled.

>
> 2. Using floor joists laid on their narrow edge (such as 2x8's), this
> anchor would end up with no wood to attach to, unless a 2x8 was laid
> flat first, and then the floor joists laid on top of that, which is not
> something I've seen.

That flat piece is how it's typically done. It's called the sill
plate
and it gets bolted to the foundation.

 (Or is there some sort of bracket made for this
> use?).
>
> Then too, making sure these anchors dont und up directly under a joist
> might be tricky too, because the location of each joist would have to be
> measured and marked on the blocks first.
>
> Anyone have any tips?
>
> Please, if you want to tell me to contact a building inspector, or hire
> a professional, dont even reply.  This is a DIY project in a rural area.
> There wont be any professionals involved, nor any inspections, other
> than getting a building permit (to keep the local officials happy and
> wealthy).  I already inquired, they said that as long as it's not a full
> time home, I just need a permit to build, and they need to know the size
> and type of construction.  (so they can raise my property taxes to suit
> the structure).

It's amazing to me there are still places in the USA where you
can build a house without any inspections at all.

[bud--]

I believe with standard lay-up the cores align. You can fill some cores
with concrete and add rebar. The top course could be offset so the cores
do not align. I think something like newspaper is used to block the core.

>
>
>>
>> 2. Using floor joists laid on their narrow edge (such as 2x8's), this
>> anchor would end up with no wood to attach to, unless a 2x8 was laid
>> flat first, and then the floor joists laid on top of that, which is not
>> something I've seen.
>
> That flat piece is how it's typically done. It's called the sill
> plate
> and it gets bolted to the foundation.
>

Detail that show a sill plate and floor above:
http://www.cochise.az.gov/uploadedFiles/Planning_and_Zoning/AFPA%20-%20Conventional%20Wood%20Frame%20Construction%20Details.pdf
page 24, fig 11.

This is standard construction now.

Anything that is in contact with concrete (sill plate) should be
pressure treated lumber.

The joists and "band" (rim joist) are secured to the sill plate. In
hurricane territory steel connectors are used to secure all connections
up to the roof. Tornadoes can be stronger than hurricanes.

Oren recently posted a link to a catalog of connectors (60M)
http://www.strongtie.com/literature/c-2013.html#

I suggest the OP read a book on construction and maybe construction for
hurricanes. (Is there a good book/website for hurricane construction?)

[DerbyDad03]

On May 13, 12:05 am, repa...@workshop.com wrote:

Have you considered builing the cottage as a circular structure? They
shed the wind much better than a flat walled structure and they look
really cool too. However, they will challenge your DIY skills to the
max.

http://www.deltechomes.com/

As far as your question, attaching the joists to the block wall is
just one of the many requirements to meet code for a tornado/hurricane
house. I realize that you don't have to meet codes for inspection
purposes, but codes weren't written just to give the authorities
something to inspect. They were written to address specific safety
issues. Build the place to code and you won't have to worry about it
getting blown away.

BTW your statement "Since the cabin will be small, that would mean is

weighs less, and thus would probably make it blow off the foundation

easier" may not be entirely true.

It's not the weight as much as it's the profile presented to the wind
and the strength of the envelope. Big or small, if it sheds the wind
correctly, it won't get blown away. Keep the wind outside of the house
and you'll be in much better shape. I saw a video of a house with a
hurricane proof front door vs. a standard door. As soon as the
standard door blew open and the wind got inside the house, it was done
for. It collapsed backwards as the wind hit both the front of the
house on the outside and the back wall of the house on the inside.

[k...@attt.bizz]

On Mon, 13 May 2013 10:36:45 -0600, bud-- <remove....@isp.com>
wrote:

When I've had it done, the concrete was done at the same time as the
floor, so the holes were just filled with as much concrete as they
would take (yes, the holes line up). The added strength of the filled
cores was wanted but not so much so that it was specified. In one
other case, filled cores were an engineering requirement so they made
sure the concrete made it to the bottom of the wall.

>>
>>>
>>> 2. Using floor joists laid on their narrow edge (such as 2x8's), this
>>> anchor would end up with no wood to attach to, unless a 2x8 was laid
>>> flat first, and then the floor joists laid on top of that, which is not
>>> something I've seen.
>>
>> That flat piece is how it's typically done. It's called the sill
>> plate
>> and it gets bolted to the foundation.
>>
>
>Detail that show a sill plate and floor above:
>http://www.cochise.az.gov/uploadedFiles/Planning_and_Zoning/AFPA%20-%20Conventional%20Wood%20Frame%20Construction%20Details.pdf
>page 24, fig 11.
>
>This is standard construction now.
>
>Anything that is in contact with concrete (sill plate) should be
>pressure treated lumber.

In the '80s I was told this was a no-no, but did it anyway.

>The joists and "band" (rim joist) are secured to the sill plate. In
>hurricane territory steel connectors are used to secure all connections
>up to the roof. Tornadoes can be stronger than hurricanes.

Yes, but nothing will save a wood structure from a direct hit. There
is only so much "hurricane banding" will do.

>Oren recently posted a link to a catalog of connectors (60M)
>http://www.strongtie.com/literature/c-2013.html#
>
>I suggest the OP read a book on construction and maybe construction for
>hurricanes. (Is there a good book/website for hurricane construction?)

Hurricanes are one thing but protecting structures against tornadoes
isn't cost justified. I don't even see much emphasis on shelters.