Adding Concrete Blocks onto Painted Basement Floor Questions

[Goatman]

We currently have a basement wall that was very bowed and we had a wall anchoring company add their anchors which has kept the problem from getting worse however, the second row of block on this wall had kicked out a couple inches. The first row I think is mostly in the floor which is probably why it hasn't moved. Since we don't have any water issues I just wanted to put a row of 4" hollow core block along the bottom of the wall to hide this. I might even build a wall over this new block to help hide the cracks in the existing wall and anchors.

I was planning on drilling some holes for rebar to reach down into the floor to help give the block some strength, This is why I was gonna use the hollow core block. My question is this, should the floor be roughed up somehow? Currently, the floor is painted. I wasn't sure if Muratic acid would remove the paint and help etch the floor for a better adherence of the block.

Any suggestions would be greatly appreciated.

Mitch

 

[Dirtmechanic]

The 7th bit from the left is useful for roughing a surface. I would just angle a diamond blade in a skill saw and cut a long groove to keep the masonry from kicking out. The metal works too, I have used those blue masonry screws and poured over them.

 

[Goatman]

The 7th bit from the left is useful for roughing a surface. I would just angle a diamond blade in a skill saw and cut a long groove to keep the masonry from kicking out. The metal works too, I have used those blue masonry screws and poured over them.View attachment 1459

DirtMechanic, thanks for the reply, sorry for delay getting back but I came down with a bad bug.

I'm attaching a picture to verify what you are recommending. Do you think I would still need to rough up the concrete in combination to the two cuts in the floor? Would the thickness of the blade be wide enough for the mortar mix to grab onto?

Thanks again for your reply.
Mitch

 

[A J]

That's a different thing....

Alright there are a few solutions to this type of problem.
Best solution if possible, is to dig down on the outside of the building and identify what is causing the lean. Then it would then be possible to re-build the portion that is damaged. Note you will want to place a line of shoring up within a foot of the end. The floor system direction is important as is the roof system, and if they are load bearing on this element.
Your solution of placing a 4" block infront of the wall and then placing another wall infront of that would work.14 gauge, 4" studs @ 12" O.C. The purpose is as follows, the block wall can be used as the sheathing and then metal studs could be solidly fasten to the block, to reinforce the block against the lateral force of the existing wall.
There are some special things you will want to do depending on the weather and the climate that you have. 14 gauge, 4" studs @ 12" O.C

To do the solution with the 4" block is difficult as you will have to had a larger diameter reinforcing bar, a #20 mm in each cell, depending on the height of the ceiling, and you will want to fill each cell with mortar/grout. You will want to lock the wall into the floor above as-well

 

[Goatman]

That's a different thing....

Alright there are a few solutions to this type of problem.
Best solution if possible, is to dig down on the outside of the building and identify what is causing the lean. Then it would then be possible to re-build the portion that is damaged. Note you will want to place a line of shoring up within a foot of the end. The floor system direction is important as is the roof system, and if they are load bearing on this element.
Your solution of placing a 4" block infront of the wall and then placing another wall infront of that would work.14 gauge, 4" studs @ 12" O.C. The purpose is as follows, the block wall can be used as the sheathing and then metal studs could be solidly fasten to the block, to reinforce the block against the lateral force of the existing wall.
There are some special things you will want to do depending on the weather and the climate that you have. 14 gauge, 4" studs @ 12" O.C

To do the solution with the 4" block is difficult as you will have to had a larger diameter reinforcing bar, a #20 mm in each cell, depending on the height of the ceiling, and you will want to fill each cell with mortar/grout. You will want to lock the wall into the floor above as-well

AJ, thanks for the reply.
We live in Cleveland, Ohio. I was told the bowing was caused by a lot of clay in front of the wall and possibly water. I added dirt around the exterior and tapered the grade away from the house 6' and put in a French drain. Then I did some work to the yard to further keep the water away from the house. As bad as the wall is, I get no water.

I really did not want to dig up the yard and was hoping this would be a way of making the wall at least look better from the basement side. Even though the wall still has a big bow in it, I don't think it moves like it used to so I think the wall anchoring system has stopped that. Mainly what we're looking at doing is cosmetic.

So if I understand you correctly, I should use a heavier duty rebar than usual in each brick? What about the angle cuts to give the mortar something to grab onto? Would I need to do that in combination with roughing up the floor?

Thanks again.

 

[Dirtmechanic]

I was thinking more of a keyway. To do what you are showing I would fasten a piece of L down with expanding redhead style threaded masonry fasteners, to the base of the wall and the floor, as a kick stop.

 

[A J]

AJ, thanks for the reply.
We live in Cleveland, Ohio. I was told the bowing was caused by a lot of clay in front of the wall and possibly water. I added dirt around the exterior and tapered the grade away from the house 6' and put in a French drain. Then I did some work to the yard to further keep the water away from the house. As bad as the wall is, I get no water.

I really did not want to dig up the yard and was hoping this would be a way of making the wall at least look better from the basement side. Even though the wall still has a big bow in it, I don't think it moves like it used to so I think the wall anchoring system has stopped that. Mainly what we're looking at doing is cosmetic.

So if I understand you correctly, I should use a heavier duty rebar than usual in each brick? What about the angle cuts to give the mortar something to grab onto? Would I need to do that in combination with roughing up the floor?

Thanks again.

Option #1... ( heavier rebar) (4" blocks) may still deflect)
Creates a retaining wall out of the new block,
(not perfect as your existing slab is most likely only 4" thick.) so you really may want to place a footing. However if you lock the wall into the top of your floor system, then it requires less load go to the footing.
Option # 2... (Use the wall studs as the reinforcing)
creates a retaining wall out of the wall studs( i have used 2x10's for this in the past, however they are only a 10~30 year solution as they do rot.) ( would not need to reinforce the footing, as the wall becomes 12" which allows for it's strength. *use building tar paper between the wood stud and the masonry to mitigate moisture transfer.
Option # 3 have a Masonry come in and repair it.. P.S that's something you can do too, it's tech that's been around before our grandparents.
This option should be done in the spring, go hire some high school kids and have them dig a 2ft wide trench besides the affect area, down to the base and then re-point it.

Exterior construction. Water Preventive treatment
The exterior grade of the surface should be away from your house.
The surface material normally should be such that storm water runs across the surface. So that water can be moved quickly away from the foundation.
What is consider bad...
Gravel along the outside, as the water goes straight threw it.
Grass is good!
Asphalt or Concrete is good, just be mindful of the joint between the building and the surface, as that's a location for water to easily join your foundation.



So if I understand you correctly,
I should use a heavier duty rebar than usual in each brick?
yeah, which should be a 3/4" diameter bar rather than a 5/8"or a 1/2 diameter.
What about the angle cuts to give the mortar something to grab onto?
The reinforcing provides the lateral load transfer mechanism. So no angle cuts should be required.

Would I need to do that in combination with roughing up the floor?
Not required with the reinforcing.

 

[Goatman]

Thanks for the information guys. Your ideas have helped me figure how I'm going to do this project.

 

[Dirtmechanic]

One question and it is an important one I missed because I was randomly kicking through posts when I found yours.

The cracks in that wall.

Are they horizontal for any length, which indicates imminent structural wall failure?

Are they stair stepped?

Are they vertical?

The reason I ask is you said the wall was kicked out a couple inches and as the discussion continued my hairs started standing up.

 

[Goatman]

I've attached a picture of most of the wall. There are a total of 6 wall anchors spaced about 4' apart. The dotted red line going off the page to the left stairs back up again. Blocks on floor are sitting loose.