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Control joints in concrete foundation walls

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#22 ·
CJ'S on the flat is one thing.....However what does one do on a hill with a series of step footings ie a series of weak points many times at odd intervals? :eek: Then there is the split level foundation tops; beam pockets, etc etc. ie low budget engineering nightmare :whistling

get me those run thru rods or the old stone basements with 3 bags of portland and the rest lime: thumbup:

just kidding Fred but you know the scene v.i.f. when things get complicated....ie mother nature can get mean! :eek:
 
Discussion starter · #23 ·
Fancis Casini said:
CJ'S on the flat is one thing.....However what does one do on a hill with a series of step footings ie a series of weak points many times at odd intervals? :eek: Then there is the split level foundation tops; beam pockets, etc etc. ie low budget engineering nightmare :whistling

:
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The publication by the PCA (which is not available on line) specifically speaks of those concerns you mentioned. Very similar to brick or block walls,they recommend control joints at abrupt wall height changes,as in a stepped footing or split level foundation.:thumbsup:
 
#24 ·
fjn said:
The publication by the PCA (which is not available on line) specifically speaks of those concerns you mentioned. Very similar to brick or block walls,they recommend control joints at abrupt wall height changes,as in a stepped footing or split level foundation.:thumbsup:
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It is impossible to put a cj at every step when the top wall is all one level.
Fred it's residential work,the coin isn't there most of the time! It will involve cj's at the stepped footings too. The walls could become weak especially on a unstable hillside! I'd rather have rigididty and continuity and screw the hairlines. imo make the waterproofing fexible, no.

ps I just got a message from a worker whom said he nearly was killed on that commercial brick building I bid on in West Haven CT that partially collapsed...the one I did the front over a few years back. He said the other side is falling in, like I said would happen! They have engineers who know more than I did,.. hell they wanted me to helicoil ties to hold bulging brick into lime mud with structual tile backup, 4 stories high and leave the rusted flitch plates.:whistling It's like they bait in the inexperienced for perhaps what seems like il intent.
 
#25 ·
Frank the beauty of post stress/ prestress systems is they use some pf masonrys ample compression strength to make up for lack of tensile strength, but they require special equipment and add steps to the finish line.

Think of pinnacles as 'polish' post tension... the added weight of the pinnacle keeps the masonry under it from slipping out place, always in compression.... Basements under two stories of plaster and lathe will crack less than a one story ranch with 3/8" drywall and 2x3 studs...

I see CJs as a battle line between the Architectural(beauty first) & Engineering(function before form) sides of concrete design.
FYI my 1923 Audel's recommends CJs every 300 feet in brick work horizontally...;)
 
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#28 · (Edited)
Eaglei said:
I agree 100% with placing control joints along poured foundation walls . Why it's not done , I think you'll get a few different answer's . My cousin has been in the poured foundation business for over 30 years and is highly regarded in the industry .Currently pouring a few foundation's across the street from me so I asked him why he doesn't do it. His answer was that if the footing's are done properly , on top of virgin soil ,the correct amount of re-bar ,depth and width of footing and the correct psi and slump of the concrete . He also waits at least a week before pouring the walls . That's the way he was taught and said he never saw anyone in the industry putting in control joints .To me it doesn't make sense , the city checks the sidewalks we pour for control joints but not for foundations .
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The Portland Cement Association is but one school of thought. The ACA (American Concrete Association) has a lot more to say about concrete, and uses, reinforcement, and even control joints.

I cannot speak for frost and freeze prone regions, but in Oklahoma, control joints are simply not done as a rule, except when specified by engineering. Also, once cured, and in contact with the stable temps of the earth, shrinkage and contraction are not a real issue....but shifting of the ground could be.

As to surface concrete and control joints, they are exposed to sun and cooling at night....of course we saw control joints, or install keyways on large floors. The concrete will grow under the sun and contract in the dark. On buildings were we have been able to get on the floor quickly and get covered, like some stores, we have fewer control joints, because they are not needed after the initial shrinkage.

As to control joints on basement walls....well shucks...are we supposed to use a gasket or keyway? I have 4 underground homes as part of my portfolio, and no leaks, no control joints, but we do waterproof the walls before backfilling. In one UG home, we literally poured the footings, big 4 foot wide and 16 inch deep sidewalks to support the 8 inch walls and 140 yard concrete roof, and had water present coming out of the sand during the pour. No control joints....but....those footings set for 3 weeks before wall construction, and 4 weeks before loading, the floors ledged the footers, and 5 weeks later, the 950,000 pound roof load was poured, no known cracks, or leaks. French drains are dry as far as I know, and there was not a control joint anywhere.....and the temps are stable at probably 65 degrees year around.

See what the ACA says about the subject. I built a home for a concrete engineer, who holds a PHD, and was the head of the School of Construction Sciences at Oklahoma State, and I would think if there were any "risk" with not having control joints in the footings, his personal home would have had them....we did, however, about double the amount of steel in the footings, and used pier pads about every 20 feet...a first for me. :thumbsup: The ACA manual was rubbed in my face during the build.
 
Discussion starter · #29 ·
Joasis said:
The Portland Cement Association is but one school of thought. The ACA (American Concrete Association) has a lot more to say about concrete, and uses, reinforcement, and even control joints.

I cannot speak for frost and freeze prone regions, but in Oklahoma, control joints are simply not done as a rule, except when specified by engineering. Also, once cured, and in contact with the stable temps of the earth, shrinkage and contraction are not a real issue....but shifting of the ground could be.

As to surface concrete and control joints, they are exposed to sun and cooling at night....of course we saw control joints, or install keyways on large floors. The concrete will grow under the sun and contract in the dark. On buildings were we have been able to get on the floor quickly and get covered, like some stores, we have fewer control joints, because they are not needed after the initial shrinkage.

As to control joints on basement walls....well shucks...are we supposed to use a gasket or keyway? I have 4 underground homes as part of my portfolio, and no leaks, no control joints, but we do waterproof the walls before backfilling. In one UG home, we literally poured the footings, big 4 foot wide and 16 inch deep sidewalks to support the 8 inch walls and 140 yard concrete roof, and had water present coming out of the sand during the pour. No control joints....but....those footings set for 3 weeks before wall construction, and 4 weeks before loading, the floors ledged the footers, and 5 weeks later, the 950,000 pound roof load was poured, no known cracks, or leaks. French drains are dry as far as I know, and there was not a control joint anywhere.....and the temps are stable at probably 65 degrees year around.

See what the ACA says about the subject. I built a home for a concrete engineer, who holds a PHD, and was the head of the School of Construction Sciences at Oklahoma State, and I would think if there were any "risk" with not having control joints in the footings, his personal home would have had them....we did, however, about double the amount of steel in the footings, and used pier pads about every 20 feet...a first for me. :thumbsup: The ACA manual was rubbed in my face during the build.
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The ACA works in conjunction with the PCA,actually some engineers work with them both. The ACA is in the process of adopting the PCA guidelines. As slow as the wheels turn,it may be a very long time before it takes place.


As far as what should be used,gasket or keyway,the answer is neither. Both of the publications listed in this thread (one has link other does not) depict method of forming control joints.


It really is very simple,one can adopt those guidelines or reject them.
 
#30 ·
One can accept the one size fits all, or one can logically conclude that they are not one application for everyone.

Temperature stable footings, basement walls, floors under protection...you would have to show the need, after cure, without expectation of settling or earthquakes, where control joints are needed.
 
Discussion starter · #31 ·
Joasis said:
One can accept the one size fits all, or one can logically conclude that they are not one application for everyone.

Temperature stable footings, basement walls, floors under protection...you would have to show the need, after cure, without expectation of settling or earthquakes, where control joints are needed.
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There is no need to try and convince those that want to dig their heels in and reject the findings of those two posted publications along with several other posts of those in the concrete field (read the entire thread).




I fully understand the comfort one can take in rejecting a procedure that is not front page news in the construction arena.For in embracing the concept one would have to acknowledge that perhaps they are not as cutting edge as they thought. One way or the other,it is no skin off my nose.


If one wants to negate the findings of those papers,so be it.
 
#33 ·
fjn said:
There is no need to try and convince those that want to dig their heels in and reject the findings of those two posted publications along with several other posts of those in the concrete field (read the entire thread).




I fully understand the comfort one can take in rejecting a procedure that is not front page news in the construction arena.For in embracing the concept one would have to acknowledge that perhaps they are not as cutting edge as they thought. One way or the other,it is no skin off my nose.


If one wants to negate the findings of those papers,so be it.
Click to expand...
Fred do you realize all the flip flop engineering that the fireplace industry went through since Rumford ..heck even from past 75 years!
They still cant get a open fireplace to perform and what was gospel 300 years ago is still better than any design out there, ratio wise. HMM?

i.e. cutting edge is temporary ....imo nothing beats compaction/slump/ ample rods in sufficing a foundations connectivity .i.e. half on ledge half on earth / on soft earth / or a soft hill side...pile driving is also key.

Here's one for ya....the arrival of CJ'S in veneers and block work called for joints at M.O.'s.....aesthetically they placed them at the jamb...intelligence via experience moved them to the lintel's end to avoid a leverage effect if any vertical movement occurred on either side!

The over excavated section of footing I spoke of at my house did settle a tad in 22 years. The veneer is lifting at the intersection of a adjacent wing where I ran a L iron up the roof and welded it to a steel post. The lower end sits on the veneer welded to 12'' L iron for bearing purpose. The slight settlement is lifting the veneer at the bearing side.
I.E. I built a crow bar! It should have merely sat loose on a plate or been pinned like the bridge plates to allow for vert movement.:whistling

Most guys lay it on the roof and lag into the framing....I did it right with through wall flashing via a hemmed copper trough over the L iron lintel. I then slipped the leafs up into the 3-1/2'' hems. Tar paper runs into the trough on the framing side and out a weeper at the soffet.

I'm debating in either pointing or removal....:eek:

scroll to the right and note the weep hole..the lintel is below that about 6'' the window sill is opening via settlement also. It is flashed but I need to at least remove that section.

just when I thought I'd have it made...:laughing:
 

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Discussion starter · #35 ·
Frank; I do realize that engineering is changing,as you mentioned the location of expansion joints in masonry have at times been re located. That is not the debate here. The issue is the mindset that says they are not needed at all.The location is incidental.
 
Discussion starter · #36 ·
Fancis Casini said:
The veneer is lifting at the intersection of a adjacent wing where I ran a L iron up the roof and welded it to a steel post. The lower end sits on the veneer welded to 12'' L iron for bearing purpose. The slight settlement is lifting the veneer at the bearing side.
I.E. I built a crow bar! It should have merely sat loose on a plate or been pinned like the bridge plates to allow for vert movement.:whistling

Most guys lay it on the roof and lag into the framing....I did it right with through wall flashing via a hemmed copper trough over the L iron lintel. I then slipped the leafs up into the 3-1/2'' hems. Tar paper runs into the trough on the framing side and out a weeper at the soffet.
Click to expand...




Frank; just shooting from the hip after reading your description of the veneer detail you used for laying brick on the sloped angle lies in the detail you used. Brick laid on sloped angle irons with a roof pitch of 7/12 or greater need vertical steel stops welded to that angle to prevent the brick from "sliding". The lack of those stops could possible be your source of trouble.
 
#37 · (Edited)
FJN: the fact that CJ locations HAVE changed tells me engineers didn't know everything about expansion/Shrinkage, and are still a long ways from Mastering masonry.

FYI, the dirty secret of 25 foot spacings of CJ in exterior CMU walls has more to do with ease of using slide rules than any science. Can you a least spell modular spacing engineers??????

Just a little thought tells one the shady sides of building won't need as many CJ as the sunny side.

A few more hours at the jobsite by engineers & archies making sure the footings are to plan and actually have all the rebars install at the correct locations would reduce the need for just in case CJs.

Frank, did you ever just use a flat lintel, lay Cmus to flashing, switch to brick above flashing/roofline, no fancy engineering required, a few hundred lbs of 4" block...heck use lightweights.
 
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#38 ·
fjn said:
Frank; I do realize that engineering is changing,as you mentioned the location of expansion joints in masonry have at times been re located. That is not the debate here. The issue is the mindset that says they are not needed at all.The location is incidental.
Click to expand...
Table 1.2
—
Expansion joint spacings
Author Spacing
Lewerenz (1907) 75 ft (23 m) for walls.
Hunter (1953)
80 ft (25 m) for walls and insulated roofs, 30 to 40 ft (9
to 12 m) for uninsulated roofs.
Billig (1960)
100 ft (30 m) maximum building length without joints.
Recommends joint placement at abrupt changes in plan
and at changes in building height to account for poten-
tial stress concentrations.
Wood (1981) 100 to 120 ft (30 to 35 m) for walls.
Indian Standards
Institution (1964)
45 m (
≈
148 ft) maximum building length between
joints.
PCA (1982) 200 ft (60 m) maximum building length without joints.
ACI 350R-83
120 ft (36 m) in sanitary structures partially filled with
liquid (closer spacings required when no liquid
present).


So...what is your point? Do you read the table above? These are general recommendations, not carved in stone. I am not placing control joints in any structural concrete unless and only if an engineer says so by design. The project I posted photos of is engineered, and has 100 foot long walls 12 feet tall, and 80 foot walls with a top of 18 feet...and no control joints.

This is not digging in any heels...this is simply doing as the engineer designs, not letting anecdotal tales of the old school dictate that contractors take it upon themselves to take on tasks that PE's will address.....if you think you need a control joint, then by all means....but for liability, run it by an engineer. :thumbsup:
 
#40 · (Edited)
The vast majority of "joints" I construct have the brick wythe filled with a compressible foam, and the CMU wythe is filled solid with a bond breaker, raked out about 1/2" and caulked with something that is supposed to stretch ~100% or more without unbonding from either panel..

the Cmus "shrink' and Brick grow, a tiny bit.

The damp proof flashing of course usually is acting as a horizontal "joint"

As CJ or EJ all add costs and present water intrusion issues, over specing them is silly.

Sadly, someone died on the 2cd of April erecting a high school PEMB exercise building in Argyle Texas, it appears to not have been braced properly. Godspeed.
 
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