Building concrete and concrete block walls on concrete floor

[Marvin Rodrgiruez]

Have existing building. client is trying to build a concrete block wall filled with concrete down the center of the floor. The wall is to be about 50 ft long the building is 70 ft long. the wall is to be at least 9ft high. The thickness of the floor is unknown. Have concern that the floor will crack. no wall footings were poured for the wall. Am using 2006 IBC need referance in code. Building is at least 50 years old.

Marvin

 

[Coug Dad]

Re: Building concrete and concrete block walls on concrete floor

Welcome to the board! Sounds like they need an analysis by a structural engineer.

 

[vegas paul]

Re: Building concrete and concrete block walls on concrete floor

Cut the floor, pour a footing with depth, width, and reinforcement that is either prescriptive from IBC 1805, or engineered.

 

[JBI]

Re: Building concrete and concrete block walls on concrete floor

I agree with both replies... Welcome to the board and provide adequate foundation for the new wall. The floor must safely support all loads. Lacking some type of engineers report that the existing is adequate (more than a one liner, please), the easiest way to deal with it is to provide an adequate foundation under the new wall.

 

[mtlogcabin]

Re: Building concrete and concrete block walls on concrete floor

Things to think about

What seismic zone are you in?

Will the wall have adequate support at the top and bottom to resist lateral movement in a seismic event?

 

[texas transplant]

Re: Building concrete and concrete block walls on concrete floor

As JD said get more than a one liner from an engineer. If he is really going to make sure the floor will support the wall, doing core samples and/or someother types of testing should probably be done. That would probably cost as much or more as just cutting the floor and using a prescriptive measure to build the wall.

Also, not knowing your role, the type of building, use of building, total scope of the project etc. make sure that state law doesn't require a design professional to be involved anyway.

 

[kilitact]

Re: Building concrete and concrete block walls on concrete floor

The best service you can do for your client is ensure that they hire a Registered Design Professional

 

[FredK]

Re: Building concrete and concrete block walls on concrete floor

Well since a solid grouted 8" block weighs about 88 lb. Then times a 9 ft high wall or 8 into 108 inches = 13.5 blocks. The weight of a block wall would 13.5 x 88 or about 1188 lbs per every block stacked 9 ft high.

Since an 8x8x16 block is 8 x 16 or 128 sq inches or slightly less than 144 per sq ft which is the measurement of soil density, you could be ok.

Only your engineer knows for sure. What did he say? :?:

 

[Marvin Rodrgiruez]

Re: Building concrete and concrete block walls on concrete floor

Well since a solid grouted 8" block weighs about 88 lb. Then times a 9 ft high wall or 8 into 108 inches = 13.5 blocks. The weight of a block wall would 13.5 x 88 or about 1188 lbs per every block stacked 9 ft high. Since an 8x8x16 block is 8 x 16 or 128 sq inches or slightly less than 144 per sq ft which is the measurement of soil density, you could be ok.

Only your engineer knows for sure. What did he say? :?:

there has been no engineering work on this project. I am not sure of the thickness of the floor. it could be 6 inches. I have not been given permission to enter the building and do any inspections. The city attorney is trying to get this owners attorney to allow me to inspect it.

 

[cboboggs]

Re: Building concrete and concrete block walls on concrete floor

Good Luck. I would have to agree with Kilitact a design professional needs to be involved in some capacity, whether it is evaluating the existing floor or designing a solution.

 

[rktect 1]

Re: Building concrete and concrete block walls on concrete floor

How about this in response? Just giving it a shot here.

Per IBC section 1805.4.1.1 footings shall be designed for the most unfavorable effects due to the combinations of loads specified in section 1605.2 or 1605.3. The existing concrete slab, without verification, would be assumed to be 3.5 inches thick and would require a design professional to calculate the applied loads to determine if it could satisfy the structural and/or bearing capacity requirements. Prescriptively, a footing width of 12 inches per section 1805.4.1 by 8 inches deep for plain concrete per section 1805.4.2.3 would be required for a new 8” thick, non-bearing, solid filled CMU wall at this location. On the drawings, provide either a new 12 inch wide by 8 inch deep plain concrete footing, a design professionals calculations and specifications and details for the new footing or a design professionals calculations showing that the existing 3.5 inch slab is sufficient for the new 8 inch, solid filled, CMU wall.

I was never a fan of KISS.

 

[Marvin Rodrgiruez]

Re: Building concrete and concrete block walls on concrete floor

How about this in response? Just giving it a shot here.Per IBC section 1805.4.1.1 footings shall be designed for the most unfavorable effects due to the combinations of loads specified in section 1605.2 or 1605.3. The existing concrete slab, without verification, would be assumed to be 3.5 inches thick and would require a design professional to calculate the applied loads to determine if it could satisfy the structural and/or bearing capacity requirements. Prescriptively, a footing width of 12 inches per section 1805.4.1 by 8 inches deep for plain concrete per section 1805.4.2.3 would be required for a new 8” thick, non-bearing, solid filled CMU wall at this location. On the drawings, provide either a new 12 inch wide by 8 inch deep plain concrete footing, a design professionals calculations and specifications and details for the new footing or a design professionals calculations showing that the existing 3.5 inch slab is sufficient for the new 8 inch, solid filled, CMU wall.

I was never a fan of KISS.

Thanks, I have finally gotten the attorneys to agree that our city code requires that I be given access to the building with no restricts. I will see what the guy did. I am the first full time code inspector for the city of Ogden KS. Population- about 1500. the town is next to 2 larger tows that strictly enforce codes. My little town has everything in place that was my condition to employment with them. 2006 codes.

I appreciate everyones contribution on this matter. I will see on Monday how many holes that i will have and how long it will take before I will be able to drink water without it spilling through those holes.

Marvin