How are you addressing cracks? - Printable Version
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RE: How are you addressing cracks? - Ernesto - 09-14-2011 07:09 PM
There's the ole saying. "Honor the joint". Can't tell ya how many of those I've seen. Thats why I would never fill it with concrete. The ceramic tile industry has addressed this.
RE: How are you addressing cracks? - CC Solutions - 09-15-2011 05:40 AM
(09-14-2011 06:41 PM)eaadams Wrote: That is interesting. I have always been told that a joint filler should be crushable so that it will not pucker up with reverse curl when the moisture reequilibtates. See ACI 302.2 and the article http://www.google.com/m/url?client=ms-android-sprint-us&devlocsession=off&ei=31dxTujvB-b_sgfI8MupAg&gl=us&hl=en&q=http://www.silpro.com/education/Reverse_Curl_Article.pdf&source=android-launcher-search&ved=0CBYQFjAA&usg=AFQjCNFWXNBRlIEHEd-mkXHyIuwI8ckBkw
The article doesn't offer a joint filler material suggestion. The forces encountered when a slab relaxes are variable depending on the moisture movement rate within the slab and the amount of displacement during the warping phase, but I still stand by my recommendation that joints be filled with a semi-rigid two-part material.
Relaxation is only one factor a control joint may be subject to. There may also be a separation at the joint, which is why the joint was installed in the first place. In either case you want a material that is as strong as it can be yet it must not be as strong as the concrete itself or you will risk damaging the concrete.
If by 'crushable' you are meaning a patch material, I say nay nay While a soft material will be easily crushable it will retain no strength after being crushed, so if a joint is moving seismically by a small amount (vibrations, flexing) the patch will break down and fail to support rolling loads. A semi-flexible two-part filler will absorb small variations in movement. Also, a patch will still displace out of a joint when crushed as it has no where else to go.
(09-14-2011 07:09 PM)Ernesto Wrote: There's the ole saying. "Honor the joint". Can't tell ya how many of those I've seen. Thats why I would never fill it with concrete. The ceramic tile industry has addressed this.
Stephen, I believe you are thinking of moving joints such as unreinforced cold joints and transitional joints. These are designed to move and the structural integrity of the building may rely on their ability to move. These types of joints may be filled with a soft filler (as recommended by the architect) which will keep debris out of the joint and still allow movement, but yes the joint may very well move and will move the flooring with it.
RE: How are you addressing cracks? - eaadams - 09-15-2011 12:06 PM
From the prior link: Fig. 3: Lapped cross-section of concrete core at sawcut joint showing patching compound thrust upward. Displacement of patching compound (arrow pointing upward) is caused by narrowing of joint (arrows) as the concrete slab relaxes from its warped posture.
So there they are showing patching material.
That is what I am talking with resilient flooring (in that case VCT) over the joint. Not so much with the 'wharehouse' type rolling load joints. (speaking of which, in my wharehouse, I actually can hear a hollow rocking motion under the joint... Oh property manager.... )
RE: How are you addressing cracks? - CC Solutions - 09-15-2011 01:10 PM
Yep I get it. Never put patch in a crack.
I have filled below curled edges and then ground the tops down. I can't remember who taught me that.... Could have been Howard, don't remember. Just drill holes in the slab and pump in grout. Great idea, I remember I was really impressed that someone thought of that ahead of time.
RE: How are you addressing cracks? - Ernesto - 09-20-2011 08:14 PM
I'd like to hear more about relief cuts in the slab every 20 feet for ceramic tile. Or what ever they call them things. Ya'll do that?
To me thats just kinda crazy and not many clients would like cuts in the tiles across a room. Maybe in commercial but in residential it can look awful.
RE: How are you addressing cracks? - CC Solutions - 09-20-2011 08:29 PM
I think you're talking about control joints. You can go right over a control joint. Typical layouts on commercial is 15' or 30'. The most I have ever ordered is a slip sheet and a soft joint.
RE: How are you addressing cracks? - eaadams - 10-19-2011 09:55 PM
JD - have you ever used the Koster Joint Tape 20/30 and KB-Pox Adhesive under vinyl flooring?
I'm thinking it might work well. Looks like what is used to cover cracks on outdoor tennis courts: http://youtu.be/hWPtxRTpUkE
RE: How are you addressing cracks? - CC Solutions - 10-20-2011 06:58 AM
(10-19-2011 09:55 PM)eaadams Wrote: JD - have you ever used the Koster Joint Tape 20/30 and KB-Pox Adhesive under vinyl flooring?
Koster has some fantastic products.
Two things about using this under vinyl floors, this tape is suitable in environments up to 10 pH, and we exceed that sometimes under vinyl floors, and it is an expensive and time consuming installation. It's really overkill wouldn't you say?
I fill cracks with a semi-rigid epoxy or urethane and patch over them. If anything moves the patch will fail no matter what joint method you use won't it?
I mean if it doesn't move you have no problem, but if the floor does move, is there anything short of a wall to wall isolation barrier that will stop the patch from cracking?
RE: How are you addressing cracks? - rthompson - 10-20-2011 09:38 AM
I have not tried. Sounds interesting.
I'll have to get some
RE: How are you addressing cracks? - eaadams - 10-20-2011 05:07 PM
Ray if you write an article on it hopefully you'll plug the Wagner forums for turning you on to it.