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Laterally Supported Foundation Wall

123pugsy

Bronze Member
Joined
Mar 20, 2013
Messages
34
Location
Markham, ON
I was reading our building code yesterday and I realized the staircase being beside the foundation means it's not laterally supported.

Is this correct?

While reading up, it stated that joists in the floor system run parallel to the wall.

See part ©

I don't understand how the walls where the joists run parallel get any support.

Am I missing something?

(2) Foundation walls shall be considered to be laterally supported at the top if,

(a) such walls support solid masonry superstructure,

For whats new, check out www.regulationsandstatutes.com 770

Queens Printer of Ontario. This is an unofficial version of Government of Ontario legal materials.

(b) the floor joists are embedded in the top of the foundation walls, or

© the floor system is anchored to the top of the foundation walls with anchor bolts, in

which case the joists may run either parallel or perpendicular to the foundation walls.
 
The lateral support is provided by the floor diaphram transferred to the top of the wall through the connections to the top plate and the anchor bolts
 
Thanks.So the connection of the floor sheathing to rim board to sill plate, with the wall connection above keeping it straight and together?In the case of my house where the stairs are right beside the foundation wall, only the external wall above the foundation wall is there, no floor system.So then, this would not be laterally supported? This is the only scenario I can see where it's not laterally supported unless there was a pony wall on top of it something.If you take away the flooring in the pick, assuming a stairway, then there is only the wall above putting pressure downwards.The reason for my concern is that I just had one of my CMU walls bow in just when I was about to apply for a building permit. I had planned to build 2 stories on top of the existing foundation wall and leave the stairway in place. But since I need to rebuild the one wall, it got me thinking about how strong the wall beside the stairs is. This stairway wall is at the opposite end of the cracked one.I'm now at a point where I may need to wipe out the whole basement I was trying to save and pouring a whole new foundation. I could now only save the slab and footing. :-x

View attachment 1079

View attachment 1079

/monthly_2014_07/wall.JPG.078613ad5f8d9f36933f14c94a3b0592.JPG
 
Rather than wipe out the basement hire an engineer. The engineer may be able to design a less expensive fix.

There are limitations on what a proscriptive building code such as the IRC can do. This is a fact that is not appreciated by many
 
Mark K said:
Rather than wipe out the basement hire an engineer. The engineer may be able to design a less expensive fix.There are limitations on what a proscriptive building code such as the IRC can do. This is a fact that is not appreciated by many
Ya, maybe it's time to get hold of the engineer, again.
 
MASSDRIVER said:
Does not show block or mid span blocking either. Brent.
Thanks.Just a visual aid. I deleted some lines when I cut and pasted.I have stairs beside the block wall now.See pic. I take it this is what they mean by laterally unsupported?If so, then it would need rebar, correct?See second image.If this is correct, I would need the wall scanned to check for rebar then?View attachment 1080

View attachment 1081

View attachment 1080

View attachment 1081

/monthly_2014_07/572953d370925_laterallyunsupportedbesidestairs.JPG.ad5c580d5fa5a2816f8d13b0f8ddc1ae.JPG

/monthly_2014_07/572953d37286d_LATERALLYUNSUPPORTEDBLOCKWALL.JPG.3ddab6606703e2c44a6d0377d2ca264e.JPG
 
My engineer just happened to inspect a foundation wall of the same vintage and saw no rebar in it at all. Figures mine will be the same.

Going to go with a new 10" concrete wall.

Thanks.
 
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