Have moved into a new condo. The basement walls are cast concrete; the house
sits on very porous soil/dirt and the grade falls steeply all around. We
have had very heavy rains during the past few months. No evidence of wet or
damp basement except:-
One wall has two cracks less than 1/16". There is some evidence of water at
these cracks. I want to attempt a seal of these cracks. I am proposing to
use acrylic caulk. I will cut a very small opening in the caulk dispenser
tube and then force as much caulk as possible into the cracks. Is there a
Stop!!! Smearing any kind of caulk from the inside will not help
you at all and will make a mess that may hinder a proper cure.
Here are some of the fast easy answers:
Proper water proofing or damp proofing (these really are different
things) can only be accomplished on the outside of the wall. The
exceptions here might be Xypex and epoxy injection.
The first line of defense involves moving surface water away from
the foundation. Make sure rain water has definite drainage away
from the house. Avoid or remove planting areas and flower beds
next to the house. Extend gutters and downspouts.
For more information Google your way to :
damp proofing of basements
water proofing basements
Keep the whole world singing. . . .
It won't work. Consider the pressure of the water six to eight foot
down. That little bit of calk may keep rain from seeping in a window or
water from getting behind the tile in the bath, but it is not going to do
the job in the basement.
As Meehan says, caulk is not going to stop a six or eight foot head of water
on the outside. However, if the water is merely a bit of seepage taking the
path of least resistance, the caulk may bar entry and force the water to
take another path along the wall. Do not, however, try caulking the 1/16"
The best way to caulk small cracks is to make them larger. If you're going
to do it, widen the crack to about a 1/4 inch (tapered back to the original
width in a sort of "V" shape). Then caulk the larger crack. The reaon is
If the crack opens & closes say even 1/64" due to thermal expansion orother
movement, that would be 25% stretch on 1/16" of caulk. If you make it 1/4"
of caulk, now you're at only about 6% stretch. That's much easier for the
caulk adhesion to withstand, and it's less likely to come loose.
As others have said, caulk won't do any good. Also keep in mind that
water getting in from the outside can freeze and make the crack worse
I wrote the following a few years ago in ahr and just cut and pasted
from google. I still believe it's one of the best products I have
ever bought :
I have a bi-level which had a crack down one corner of the poured
walls. The downstairs is only 2 1/2 feet under ground but during very
heavy rain falls it did leak.
I ended up buying LCR (liquid concrete repair) by Polygem. The kit is
expensive but it's worth every penny and very simple to use.
You attach ports over the crack at 1' intervals and use a 2 part epoxy
to "seal" the crack and hold the ports in place. Then starting at the
bottom you inject a thin liquid resin into the port. The epoxy
applied earlier holds the resin in the crack, after a while the resin
starts to come out the port above it. You plug the bottom port and
start injecting the next port and so on till you hit the last port.
Once done all the ports are plugged up and by the next day the resin
is cured. If any of the crack is exposed outside you'll actually see
the resin on the outside of the concrete wall, it completely goes
through one end and out the other for a 100% seal.
Menards sells these kits and one kit is enough to do a single 8' long
crack. I paid $55.00 for the kit and still have one unused tube since
my walls are only 40 inches. Supposedly it's a permanent fix and from
the way it worked I believe the claim.
Here's a pretty good web site that explains everything.
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