Are there any regulations for basement heights?

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Posted by: from Lindsay
10/4/2015 at 8:11:50 AM

When my contractor did our 1000 sq ft addition we included a full basement as well, instead of using support posts we opted for 2 steel beams instead.

My issue is the beams are only 80" from the gravel floor to the under side of the beams, (the contractor has not poured the 3" floor yet). I mentioned to the contractor about my concerns because after the floor pour I want to finished the new basement, so once I put a bulkhead & drywall on the ceiling & add a floor i'm only going to have about 73" + or - of head room.

My drawings call for 12 courses of cinder block but we only have 11 courses, I think this where the height issue lies, I suggested to the contractor that he raise the beams up into the floor joists but he is telling not to worry everything will look good if I finish the basement properly. I should mention that where the new addition meets the existing home the floors line up and the existing basement height also seems line up with the addition.

Where do I stand legally and what might I do about my situation? Any advise would be greatly appreciated.

Thank you,


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Date/Time10/4/2015 at 12:14:03 PM

Code requires min height 6 ft 8 clearance..your about I block short..the contractor should know the specs...need to stop the work have a engineer get involved and local building inspectors (as I feel this work was not done with either) and go from there...solution...dig deeper if allowed.

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Date/Time10/4/2015 at 12:37:31 PM

Hi Frank,

I don`t think you need an engineer as the other post mentioned. I would ask the contractor to make the beam a flush mount. This way you will gain the extra inches for your basement height, It is quite easy to do now before the floor is poured.



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Date/Time10/5/2015 at 9:53:33 AM

As noted above, now is definitely the time to have your contractor rectify the problem to get your proper height. I'm wondering what your contractor meant, by throwing it back to you, "It will be OK if YOU finish the basement PROPERLY" ?

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Date/Time10/8/2015 at 8:35:57 PM

Hi Fred,

To answer your posted question: Yes. Basement space must be 2100mm or 6'10 5/8" over at least 75% of the basement except under beams and air ducts where it can be reduced to 1950mm or 6'4 3/4".

As for your Contractor not following what was provided for in your drawings, that is a serious problem and if they have not provided what they were contracted to do than you have a solid legal case. Please understand that I do not know the specifics of your case so I cannot qualify your situation or predict any outcome of legal proceedings.

As for the 80" under the beams: Technically a basement slab can be 75mm or 2.95" thick on top of 3.93" of clean gravel. So technically the underside of those beams will "squeak" by, until you have your finished floor going in, then you will have an issue as a finished floor and drywall ceiling will reduce the effective ceiling height to a height that will violate the Ontario Building Code.


Jason Irving

Cedarfalls Building Consultants Limited

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