# Basement Concrete Curb



## Beepster (Oct 19, 2009)

I believe I have the same type of basement. I believe that it is a 4" x 8" x 12" concrete block sitting on the footing with the slab poured around it. i secured the joists with bottle jacks, cut out the bottom plate and studs in the way, and used an angle grinder with a diamond blade to cut the block out. It creates a crapload of dust so wear a mask and have a window open.

I then framed in the doorway with 4x4 posts on each side and a 4x6 header. I tend to over build. Then I looked at the doorway to the utility room about 10 feet down and it just had a 2x4 on each side with not much more than that above the door.

B


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## brockmiera (Oct 9, 2012)

Ha ha ha. Thats hilarious. I was there with my IBC Span charts figuring out how to support the wall. Cutting out top plates, double 2x6 header, number of jack studs when my girlfriend says, "Hey, why dont you just do it like this one?" sure enough down the wall are two different framed openings with a 4x4 stuffed under the double top plate with a 2x4 on either end. 

My curb is a little differend though. Its 4" tall x 3.5" wide. Its poured concrete not CMU. I figured I'd use an angle grinder and diamond blade but I'll only be able to get down maybe 2" with the 4 1/2" grinder. Planned on using some water to keep the dust down. Should I use a cold chisel on the rest of the removal after I've scored around the whole thing?


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## joecaption (Nov 30, 2011)

Do not use 4 X 4's or 4 X 6's for framing.
Both after a while will check along there length and like to twist or curl.
Use double up 2 X 4's instead. For the header use 2 X 6's with 1/2 plywood or OSB in the middle. That way it will come out even with the sheetrock.


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## Beepster (Oct 19, 2009)

joecaption said:


> Do not use 4 X 4's or 4 X 6's for framing.
> Both after a while will check along there length and like to twist or curl.
> Use double up 2 X 4's instead. For the header use 2 X 6's with 1/2 plywood or OSB in the middle. That way it will come out even with the sheetrock.


I have since learned that two 2x4s (or 6s) are stronger than one 4x4 (or 6). Who knew? Nobody told me. The best advice my old man imparted on me was to never get married. Uh...ok...can I finish watching Scooby Doo now dad...

B


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## brockmiera (Oct 9, 2012)

joecaption said:


> Do not use 4 X 4's or 4 X 6's for framing.
> Both after a while will check along there length and like to twist or curl.
> Use double up 2 X 4's instead. For the header use 2 X 6's with 1/2 plywood or OSB in the middle. That way it will come out even with the sheetrock.


So I dont have enough headroom under the double top plate to put in a 2x6 header. Since I'm only spanning two joists will a 2x4 header work? I'll have to remeasure the height. Maybe I can rip a 1/2" off of a 2x6 and get 5" in there.


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## joecaption (Nov 30, 2011)

Got a picture?
For that short a distance it should be fine.


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## brockmiera (Oct 9, 2012)

No but I'll take one tonight when I get home and post it.


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## stadry (Jun 20, 2009)

make your cuts w/diamond blade on the grinder - 1 vert at ea end AND 2 horizontals 1 on either side of the curb,,, then use a sm chipping gun ( bosch bulldog type ) w/1" chisel bit & bushing tool,,, vac would help trap what dust there is

ixnay on the wtr UNLESS you have a gfci on the tool's circuit


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## brockmiera (Oct 9, 2012)

itsreallyconc said:


> make your cuts w/diamond blade on the grinder - 1 vert at ea end AND 2 horizontals 1 on either side of the curb,,, then use a sm chipping gun ( bosch bulldog type ) w/1" chisel bit & bushing tool,,, vac would help trap what dust there is
> 
> ixnay on the wtr UNLESS you have a gfci on the tool's circuit


Ok I can do that. 

I used an air hammer with chisel attachment to make a hole in the floor to replace my P trap. Do you think that would work ok so I don't have to go and rent something?


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## stadry (Jun 20, 2009)

unless you have lotsa air, it'll be slower & make more dust but if the ? was ' can i,,,, ? ' of course - ' ok ' is another matter - don't like air-powered dust-making tools in my house but its your house :laughing:


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## brockmiera (Oct 9, 2012)

Ok So i framed the opening and when I cut the sill plate out of the opening I found some concrete blocks that are hollow. Why would these be here?


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## brockmiera (Oct 9, 2012)

Here are more pics


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## brockmiera (Oct 9, 2012)

So I read back thru this thread and it looks like you were right after all Beepster. Once you got the block out of the concrete did you fill in the void left with new concrete?


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## brockmiera (Oct 9, 2012)

I also noticed some metal shims, Im guessing, on the right side of the block in that photo. I'm guessing these were in place as forms for when half of the basement slab was placed. I'm also assuming there is a footer below them. If I remove these should I fill the void with concrete?


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## Beepster (Oct 19, 2009)

brockmiera said:


> So I read back thru this thread and it looks like you were right after all Beepster. Once you got the block out of the concrete did you fill in the void left with new concrete?


YES! Vindication...not that you called me a liar or anything...

I have not got that far but will do in the next weekend or two. Probably fill the holes with left over Quickcrete. Then going to have a buddy help me do a self levelling cement on one side. There is a slight difference in height (1/2" or so) between the two sides. The higher side is going to be carpet and pad and the lower side is going to be a vinyl sheet (bathroom) so i want to lift the lower side up a bit and get it perfectly level in the process.

B


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## concretemasonry (Oct 10, 2006)

The 4" block are common in many places. Despite being "hollow" (most 4" are not technically hollow for structural purposes), they are still far stronger than the 2x4 walls bringing down rhw load.

Often, a basement starts with strip footings for ALL walls to provide a base to spread the loads out into the lower strength soil below. Even planned interior walls have strip footing placed at the same time because of costs. The poured concrete footings are not totally precise, but good enough to set forms on (dry solid base) or block on and the interior walls usually get 4" wide block (same width as a 2x4) that can be set in mortar to provide a very level and accurate base for the "nail benders" to work off of.

After the exterior walls are up and basement is capped the basement floor (usually 4" thick) is poured against the exterior walls and up to the 4" block that are already level. leaving about 4" of the exterior walls and the 4" exposed curb that reduces the moisture transfer from the soil through the wood that is usually not treated. Often the basement slab is not poured until the garage and slabs are poured and furnaces can be hung temporarily to provide heat/drying for the home during construction and the basement buried utilities are in place.

You can fill the cores of the 4" block to give you a "warm and fuzzy" feeling and make attaching a plate in place easier.

Dick


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## brockmiera (Oct 9, 2012)

Ok so if I read thru the information that you've written (which I thank you for!) I can removed the block that is there now and simply fill in that void with concrete? 

I need it to be removed at least to the level of the floor so I can have a closet door installed there.


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## concretemasonry (Oct 10, 2006)

Should be no problem to knock out what is necessary and fill everything to make a smooth floor. The block were just installed because it was cheaper if the complete wall was needed afterward for a continuous wall. If you are worried about anchorage of the studs (heaven forbid!!), you can set a couple of bolts into what you fill the block voids with.

Dick


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## brockmiera (Oct 9, 2012)

Normally I would worry about anchoring the sill plate but there is one to the left of and the right of the opening I put in there. Thanks again for everything!


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