Replies

1. 
   Piffin | Oct 27, 2002 12:05am | #1

   I don't know what kind of caulk you already have but putting that aside, the one thing that sends up a red light for me is that concrete is already crumbling away. This is not a good sign. Is this the only place it is crumbling or are there several other spots on the wall where is is flaking off? It sounds like something is causing it to deteriorate or it had a poor quality mix in the first place.

   If you take a wire brush to the flaking areas, does it easily keep making powser or is the underlying concrete sound and solid? If so you can clean and caulk it. Concrete in a tube isn't my cup of tea. Read labels on all your caulks. It will tell you if it will stick to concrete. If the old concreter keeps flaking and making powder, you have bigger problems and no caulk will stick for long.

   Why do you want to caulk? Is this for appearance only or is the weather coming in? A joint like this is not common so therre is a lot to analyse.

   .

   Excellence is its own reward!

1. 
   suzy | Oct 27, 2002 01:05am | #2

   i live in a 70 year old house in the northeast.  i am not sure why the concrete is crumbling, but does the age of the house make it seem more reasonable.?  the reason that i want to fill in the gap between the concrete and the wall is to make it more weathertight.  i thought that maybe if i filled in this gap, it would make the house a little bit warmer in the winter--eliminate a source of entry of cold air.  i am sure that this crumbling wall has been there for decades, but i did a really thorough cleaning out of my garage last week and noticed it for the first time.

   the caulk i usually use is Phenoseal brand vinyl adhesive caulk.  it is easy to use.   i know that i would have to apply the caulk in several layers,but i have three tubes in my cellar, and that makes it easier, by far, than going to the hardware store !!!

   thanks, susan

2. 
   FastEddie1 | Oct 27, 2002 01:09am | #3

   Wonder if maybe the builder used a thin veneer coat of plaster/concrete to cover flaws in the poured wall.  Or maybe it's a cmu wall with plaster finish.  Need details or pictures...

1. 
   suzy | Oct 27, 2002 01:37am | #7

   i just do not know enough about this.  what is a cmu wall???

   do i really need to be concerned about this?  i was hoping to just schmere a little something over it and go back to my 60+ hr/week job, my housekeeping, end of the season gardening, carpentry hobby, cleaning out the basement, attic, closets, etc etc--in my spare time. thanks

1. 
   RW | Oct 27, 2002 01:22am | #4

   Other issues aside - if you're caulking something you're going to paint, you can use about any latex you want. If you're caulking something where the caulk needs to stick to the concrete (or to the concrete on one side and framing on the other) find some NP-1. Sonolastic sells it and it's evil sister SL1 but the NP is thick and hard and you can tool it in a vertical joint. But it's not easy to spread, and spit on the finger doesn't do much good. Two things work that I've used. A plastic spoon if the joint just needs to be tooled but not so much pretty, but if you want to really smooth it like regular caulk, coat your fingers in Vagasil. Clean anything you get on you with lacquer thinner.

1. 
   suzy | Oct 27, 2002 02:43am | #11

   thanks to all of you who have responded.  i see that i need to give some more info.  the concrete surface that i mentioned is the interior wall of a garage, and it abuts (?) (90" degrees to) a wall that used to be concrete, but was sheet-rocked over a number of years ago (before i knew very much) to keep the house warmer (add an extra layer for insulatioin to an outside walll) .  the sheetrocked wall is the exterior wall to the dining room (i.e., the garage is attached to t he house, attached to t he dining room.).  i do not care about cosmetics at all.  not about painting.  and maybe filling this gap will not do much to keep the house warmer.  but it just looked stupid to me when i saw it this afternoon to have this gap between the concrete and the wall it touches.   seemed that it would do some good to fill in the gap.  i do not think that there is any plaster on either surface.  --just the  concrete wall and the sheetrock that some carpenter-who i know now did a really lazy and sloppy job-stuck up for me 15 years ago. 

    i just want to know what will stick to the concrete. the gap is maybe 1/2" or less wide in most places, and 1/2- 1" deep in its worst spots.  the man at the hardware store said concrete, and i do not like that idea at all.  not sure that i need to put in foam, not sure that it is deep enough for that.  i thought that maybe just putting in the phenoseal in two or three layers, because i know that it shrinks as it cures, might "fill" the bill, and easily.    thanks

2. 
   FastEddie1 | Oct 27, 2002 02:56am | #13

   Ok, I'm a little dense.  I'm still having a little trouble imagining the layout.  BUT...a couple of things you said/proposed are wrong, and you should not proceed.  not sure that i need to put in foam, not sure that it is deep enough for that.    It's not entirely a question of depth.  You DO NOT want the caulk to stick to the bottom or third side of the gap.  It will fail much too soon.  it shrinks as it cures,   and as it's shrinks, it just might pull away from where you want it to stick.  what will stick to the concrete   Lots of stuff will stick.  The phenoseal will do an ok job.  If you have to go buy more caulk, don't buy the cheapest stuff.  What will it take...4-6 tubes?  And whats the difference in cost per tube...$2-3 or maybe $15 for the whole project?  As Martha Washington once said "Penny Wise and Pound Dumb"  or something like that.  :)

   Will you hurt our feelings if you don't foillow our advice?  Maybe.  But if you don't follow our advice, and you come back later and report that the failures we predicted did happen, and how can you now fix the new problem, then we start to laugh and talk about you.

3. 
   suzy | Oct 27, 2002 03:11am | #14

   no, no.   sorry.  it is not dollars and cents.  honest.  it is just that i have the tubes alrealdy, and i do not have to schlep to the hardwarde store again to make another purchase.  i know that it is worth buying a good product.!  it is just that i have too many things to do, and i thought that i could save about 1/2 hr by using what i had on hand....and please, please, do not laugh at me.  please!!!!!

   if the crack is 1" deep at this deepest, i did not think that i would need to put in a 'filler " like foam.  it sounds like you all think that i do.  !  thanks

4. 
   calvin | Oct 27, 2002 02:47pm | #15

   suzy, respectfully, go to a concrete/masonry supply.  Buy enough backer rod (a little larger diameter than the gap) and get either the sonolast product or a urethane caulk from Tremco.  Stuff the backer rod about a half inch into the crack.  Mask each side of the crack if you want a neat job.  Caulk, peel away the mask and your done with something that will not shrink, crack or peel.  Check the exterior and treat that as well.  Best of luck.__________________________________________

   Remodeling Contractor just outside the Glass City.

   http://www.quittintime.com/

    

5. 
   FastEddie1 | Oct 27, 2002 05:00pm | #16

   Well, I've had time to sleep on this one, so here's my cureent thoughts.  As one of the earlier messages said, you're dealing with people who like to do things the right way.  Why?  Well, if we're getting paid for the job, we don't want to come back later and redo it for free.  And call backs aren't good for the reputation either.  There's a difference between a temporary patch to get through a situation and a cheap hack job.  If you have a suitable caulk on hand and don't want to spend money for more (nothing wroing with that), at least install the product properly.

6. 
   suzy | Oct 27, 2002 06:00pm | #17

   i have learned a lot from this discussion.  and i thank you all.   -again, it is not a matter of money, of spending the money to buy the best product.  it is a matter of TIME--what i can get my hands on without too much effort.  i do not even know where there is a masonry store in my area.  i am confessing that i just went to the local hardware store [it is sunday morning] and purchased interior/exterior spackle.  [please, no booooo's!)  it is a thicker consistency than phenoseal, and may stay put, i.e., not run down the wall.  it is a warm enough day here, in NJ ,to do this repair , and next weekend may be too cold.  if it is a mess, and does not hold up, i will have to log on under a false name, so i do not have to tell all of you that you had better suggestions.   i just do not have the time to drive around and find stores. thank you all again.

7. 
   suzy | Oct 27, 2002 08:11pm | #18

   hi, all.  maybe this is the last word on this.  i finally got to the garage, with my spackle, and started to look really carefully at  everything.  there is a large separation betweent the ceiling and the wall, adjacent to the house.  i have been pushing in tons of fibreglass batting with a putty knife.  that room adjacent to the garage has always been the coldest room in the house [i have replaced the windows, etc.].  maybe the problem was this exposed space that is now stuffed.  would/t it be great if i hav warmed my room up a little. !!  [it seems like the spackle/caulk etc is the minor problem.  another lesson to me: examine the WHOLE situation before i go to work on the solution.   !! thanks again  susan

8. 
   r_ignacki | Oct 27, 2002 10:10pm | #19

   if you gonna "spackle" that crack, the way to do it nicely w/o smearing it over the 'crete, is apply a plastic bead made just for this first, havn't seen this at home depot, you may have to go to a drywall supplier, they call the stuff here 'easy mask' , and they'll sell you the contact cement to put it on with. Put that on then do your spackle, when your finished there is a little "fin" that you peel off. Looks pretty.listening for the secret.......searching for the sound...

9. 
   suzy | Oct 27, 2002 11:29pm | #22

   hi, red.  i am not worrying about cosmetics at all.  this is the ceiling of a garage and i still have home office work to do this weekend..  is there anything wrong with my stuffing a bunch of fibreglass batting?  the space/crack is about 1/4".  but there is about 4" of empty space behind the crack. thus the firbrglass.  then maybe next weekend, i will put in the spackle?  again, i am just trying to improve the insulation of my house.  i have been in the house for 30 years and never, ever even noticed the ceiling of the garage before.  so i do not care what it looks like.  thanks

10. 
    FastEddie1 | Oct 28, 2002 12:34am | #23

    If you're starting to see a bigger problem than you first thought, you might post a message in the "Help wanted work wanted" section of this forum and see if anyone lives/works in your area.  Most people here would stop by and give an opinion as to the seriousness of the problem for gratis.  If you do post for help, hold off on the spackle until after it has been looked at.

11. 
    Piffin | Oct 27, 2002 10:27pm | #20

    It's starting to sound like you've got problems with that wall moving and possible structural problems. It might be wise to look for a reputable contractor in the area to have a look see..

    Excellence is its own reward!

12. 
    suzy | Oct 27, 2002 11:23pm | #21

    piffin, the house was built before WWII.  i would expect that there is some movement in all these years. 

2. 
   FastEddie1 | Oct 27, 2002 01:25am | #5

   Well, based on your second message to Piff, it soulds like you want to close the gap to keep drafts out, so yeah, you probably need to addrsss the issue.  My first comment was posted before your secoind answer, so I may have been on the wrong track.  CMU is concrete masonry unit, also known as concrete blocks.  Some walls are concrete blocks with a plaster coat to make them look more attractive.  If the plaster is flaking off, it should not affecyt the structural soundness of the wall, but it does look bad.  Is the entire outside wall of the house the same concrete construction, and is this sheetrock wall an interior wall dividing off the garage or laundry room or something?  Is the other side of the sheetrock wall exoposed to the outside?

   YOu don't want to just glob the caulk into the gap.  First, it might take a lot of caulk, more than necessary.  And second, you only want about 1/4" thick caulk bead.  Fill the gap with what is corrctly called backer rod...you probably won't find that at the Depot, but you might.  It's just a long round piece of foam, like those noodles they wave at basketball games, but a lot smaller.  What also works well is almost any foam weatherstrip, and Lowes and the Depot sell a variety of sizes.  Get a size that you have to squeeze into the gap, and push it in far enough so that it is a little below the surface, then caulk.  In a pinch you could stuff the gap with newspaper or old pantyhose or whatever you have on hand.  The technical reason for doing this is that you don't want three sided adhesion of the caulk...you only want it to stick to the concrete on the left and the sheetrock on the right and nothing behind it.  The foam filler acts like nothing because it stretches easily and even tears itself apart before the caulk is pulled loose

   Edited 10/26/2002 7:37:03 PM ET by ELCID72

3. 
   Piffin | Oct 27, 2002 02:38am | #10

   Suzy,

   As you can tell from the multiotude of responses and questions, this is "Fine Hombuilding"

   It attracts those of us who like to do things right so we dig deep.

   Sometimes it can amount to overkill but we wouldn't want somebody to say, "I read it at Breaktime so it must be right"

   But the simple fact is that, Yes, you can jam any kind of caulk you like into the crack to keep drafts out. It might only last a few weeks or months instead of several years, and you might end up needing to dig it our in order to finally do it all right for a permanent fix. But you won't hurt a thing by using what you have.

   Well, you might hurt a few feelings.....

   Excellence is its own reward!

1. 
   FastEddie1 | Oct 27, 2002 02:45am | #12

   this is "Fine Hombuilding"    What?    Building by Fine Hombres?

2. 
   DaveMason2 | Oct 27, 2002 01:37am | #6

   I use Sika-flex on places like that. It's a grey caulk that is made for concrete.

    Good luck, Dave

3. 
   rjw | Oct 27, 2002 01:38am | #8

   Some questions:

   1.  What is on the other side of the wall and the corner?  Is it an outside corner, or does the concrete wall extend in straight line/plane beyond the sheet rock wall?

   2.  If the sheetrocked wall is also an exterior wall, what is on the outside of that wall?

   3.  Is the area in question above the exterior grade level or below it? 

   4.  Does it look like repairs have been done there before? 

   5.  Other areas of the concrete wall?

   6.  Are there any water sources outside of where the concrete is damaged?  Soil sloping topwards the house; a downspout emptying directly on the ground at that location?

   General comment: it sounds like caulking the area would treat the symptom, but it would probably be better to cure the problem if we can figure out what it is.

4. 
   MarkH128 | Oct 27, 2002 02:17am | #9

   I doubt sealing the crack will make any difference at all in terms of warmth. If you want (or need) to seal it I suggest that you add a moulding instead of patching the crack. Use a construction adhesive to adhere the moulding (or a board) to the concrete, and caulk the moulding to the drywall.