Filling Control Joints in Concrete

[sbosecker]

About 2 weeks ago I had the concrete floor of my new building treated.

The floor was a mess due to the construction activity that has taken place since it was poured in December.

The crew extensively cleaned the floor; did some grinding; put down a densifier; put down a sealer.





I'm pleased with the result. Yesterday I was out in the building and realized the control joints that were sawn into the concrete would get filled with "stuff" when I start using the place.

Any thoughts on what, if anything, I should do to prevent dirt and such from getting into the control joints. I did a search but most of the things I found didn't really fit my situation.

I asked this question in my build thread and got a couple of answers. I decided I probably should post something here to get a more comprehensive set of responses.

Scott

 

[larry_g]

Ya wouldn't of had this problem if you had used Zip Strips. I've seen this discussed a few times on the board and if large ditches then use a foam backer and Silkaflex or if small cuts then the backer could be omitted.

lg
no neat sig line

 

[jedeyeben]

I just recently sealed my floor and went back with a self leveling caulk in my joints for that same reason. It filled in the joints enough and was smooth enough that I don't feel anything will get stuck.

 

[Chris705]

Sawn control joints ... Use 1/4" backer rod. Goes in easily with the use of a screen roller tool. Then the Silkaflex self leveling joint filler flows right in. I set my backer Rod about 3/8" of an inch below floor level. That saved an awful lot of expensive coin filler material. I also let the filler set up a little proud of the floor level and after a couple of days I used a single edge razor blade scrapper to cut flush with floor. Came out great!

 

[sbosecker]

Ya wouldn't of had this problem if you had used Zip Strips. I've seen this discussed a few times on the board and if large ditches then use a foam backer and Silkaflex or if small cuts then the backer could be omitted.

lg
no neat sig line

I just recently sealed my floor and went back with a self leveling caulk in my joints for that same reason. It filled in the joints enough and was smooth enough that I don't feel anything will get stuck.

Sawn control joints ... Use 1/4" backer rod. Goes in easily with the use of a screen roller tool. Then the Silkaflex self leveling joint filler flows right in. I set my backer Rod about 3/8" of an inch below floor level. That saved an awful lot of expensive coin filler material. I also let the filler set up a little proud of the floor level and after a couple of days I used a single edge razor blade scrapper to cut flush with floor. Came out great!

Thanks guys!

Is it Silkaflex or is it Sikaflex? There seems to be a couple of products with very similar names.

Best regards,

Scott

 

[DC73]

http://www.homedepot.com/p/Rust-Ole...oncrete-Patch-and-Repair-Kit-215173/202097324

I used this last fall to fill in 3 control joints of about 16' each before I put down Rust Bullet. So far so good. I can't even find where the control joints used to be.

DC

 

[TypeRx]

^^^How many coats of RB did you put down? Did you have to sand the concrete patch & repair kit at all (I read it was incredibly hard to do so).

 

[toplessHO]

clean dry sand will work to fill also
just dont let it get wet or pack it in
about 1/2 inch below the surface is fine
you can use a paint stir stick with tape around it to set the depth
then add favorite caulk

 

[DC73]

^^^How many coats of RB did you put down? Did you have to sand the concrete patch & repair kit at all (I read it was incredibly hard to do so).

I put a diamond grinding wheel on my angle grinder to get the epoxy flush with the concrete. It made quick work of it but you have to be careful not to put gouges in the concrete.

For the Rust Bullet, I did 2 coats of gray, flakes on the 2nd coat, 3 coats of clear with anti-skid. Didn't necessarily need the 3rd coat of clear but I had enough left to do it and figured I might as well use it up.

DC

 

[NUTTSGT]

I used Sikaflex concrete repair on my saw cuts. It's what HD had in stock at the time. I masked my joints to give a clean finish. Pics in the Refurb thread.

 

[sbosecker]

http://www.homedepot.com/p/Rust-Ole...oncrete-Patch-and-Repair-Kit-215173/202097324

I used this last fall to fill in 3 control joints of about 16' each before I put down Rust Bullet. So far so good. I can't even find where the control joints used to be.

DC

clean dry sand will work to fill also
just dont let it get wet or pack it in
about 1/2 inch below the surface is fine
you can use a paint stir stick with tape around it to set the depth
then add favorite caulk

I used Sikaflex concrete repair on my saw cuts. It's what HD had in stock at the time. I masked my joints to give a clean finish. Pics in the Refurb thread.

Thanks guys...

I went out and checked my situation. Looks like I've got about 500 linear feet of control joints.

NUTTSGT - Did you put any kind of "filler" into the joint before pumping in the Sikaflex?

Best regards,

Scott

 

[OKDart]

I would recommend backer rod or something to fill the void. I didn't use any and my saw cuts were approx. 1" deep, it took 1 29 oz. tube of caulk to do 20 feet, that will get expensive at 500 feet. I would advise using masking tape too.

 

[sbosecker]

I would recommend backer rod or something to fill the void. I didn't use any and my saw cuts were approx. 1" deep, it took 1 29 oz. tube of caulk to do 20 feet, that will get expensive at 500 feet. I would advise using masking tape too.

OKDart,

I checked the saw kerf and it looked to be 3/16". The smallest diameter Backer Rod I've seen advertised is 1/4".

Any thoughts on whether or not that would work.

Best regards,

Scott

 

[Chris705]

Yes...the backer rod will fit in there....just push it in....set it down to a proper depth of abut 1/4" or so....

AND I stopped at the nearby HD for lunch and saw that it is Sikaflex not Silkaflex as I had spelled....

 

[NUTTSGT]

Thanks guys...

I went out and checked my situation. Looks like I've got about 500 linear feet of control joints.

NUTTSGT - Did you put any kind of "filler" into the joint before pumping in the Sikaflex?

Best regards,

Scott

No, not that I remember. This is what I used.



The stuff I used was quite stiff and did take some effort to squeeze the caulk gun. I masked the joints as to not make a mess and this was my result.



It worked fine for me and I wasn't planning on coating the floor, just a garage that gets about anything done in it.

 

[jhelrey]

I wonder if you could use Polymeric sand just like you would with pavers? Would be cheap and fast to do.

 

[sbosecker]

Lots of good ideas and examples; thanks to all who have posted so far.

I have a question for anyone that used a Backer Rod to help fill the control joint:

Did anyone use a Backer Rod Tool to set the Backer Rod at a consistent depth?

Something like the Albion 640-5

Scott

 

[jchetty]

Lots of good ideas and examples; thanks to all who have posted so far.

I have a question for anyone that used a Backer Rod to help fill the control joint:

Did anyone use a Backer Rod Tool to set the Backer Rod at a consistent depth?

Something like the Albion 640-5

Scott

Just when you think you saw every tool...nice find. Does it work well. This free site is expensive.

 

[jedeyeben]

Much like nuttsgt, I used a similar product and just gunned it in. Large caulk tube of Quickcrete brand self leveling sealer. Went in fluid and easy, didn't bother to mask it.


Sent from my iPhone using Tapatalk

 

[Chris705]

I used a simple window screen spline installer (rollers on each end) to set my backer Rod in my saw cuts.

 

[sbosecker]

I used a simple window screen spline installer (rollers on each end) to set my backer Rod in my saw cuts.

Chris705,

Something like this tool at Home Depot?

Best regards,

Scott

 

[Chris705]

Yes -that's it.

 

[sbosecker]

I applied my first small tube of SikaFlex into some of my control joints yesterday. I'm pleased with how it turned out.

I documented what I did in my build thread - Post 1252.

Scott