I recently purchase a new home, constructed this past spring. The concrete foundation was poured in March. I have noticed several cracks in the interior part of the wall and was wondering at what point do they become a concern. The builder has told me that the foundation will crack, that’s it normal as the house and foundation settles. I have noticed a long vertical crack in wall from the top where main load bearing beam rests on the wall, down about three quarters on the wall to the floor. I measured the thickness of the crack and it is very slightly thinner that a quarter, I can’t slip the quarter into any part of the crack, but almost. From what I can tell the crack does not transmit to the outside of the wall, but then again I can only see the top 1 foot of the wall. I do have some other hairline cracks but I am more concerned with the bigger one. At what point do I get the builder back, what does a “concerning” crack look like? Does the crack have to transmit to the outside for me to be concerned?
Thanks for all of your advice.
Replies
A box-out, like the one you describe for your support beam bearing, is a natural place for concrete to crack. Cracks in concrete always seem to develop at a square corner if not reinforced to guard against this.
You say it only goes part-way down the wall? It probably isn't a shear crack or it would go all the way to the footing. It most likely is just shrinkage, but to be safe set up some spotlights and document with a camera that will put the date you took the photos on the pictures. Send one copy of the photos with a Registered Letter to your builder. Monitor the crack each month to determine if it is growing in length or width. If yes, send this documentation as before. Once your sure you don't have a problem with your foundation, go buy some injectable epoxy from your local building supply store or Hilti dealer if you have one near and inject the crack to seal from future leakage.
To document the crack size, find some flexible mylar rulers and mount several across the crack at various locations, making sure just the ends are attached to the wall. A dab of silicone should do just fine. Also mark the end of the crack with a date next to a "crows foot". A carpenter's pencil or lumber crayon should work just fine for this. Record in writing and with photos the width of the crack as determined by the rulers you mounted over the crack.
If this is too confusing, email me and I'll try to make a better explanation.
Eric
I've also heard of epoxying a small piece of glass over the crack. If it breaks in time, the crack is spreading. You can easily tell at what rate by periodically measuring the crack in the glass. Assuming it breaks cleanly.Andy Engel, The Former Accidental Moderator
Andy
Now THATS a thought for your next article. I never heard that one before and it sounds very interesting. Cracks in cellar walls are a serious concen to new homeowners that dont know much about reno work. I've been doing this almost 30 years and never heard that technique before. VEry cool. Sounds like a good thought for an article....along with tapeing glass accross pumbers .....ohhhhhh, forget that one.
Be well
Namaste'
Andy
It's not who's right, it's who's left ~ http://CLIFFORDRENOVATIONS.COM
There are also glass slides with scales and a cross hair that can be used to measure relative movement.
Using a single piece of glas will tell you if there's any movement, but sometimes you'll get seasonal crackes which open and close depending on soil conditions.
Thge cheap way: get some really cheap masking tape and tape it across the crack. The cheaper the better because it'll dry quicker. Tears or wrinkles will indicate movement.
Thank you all for some great advise, you are all true professionals.
My brother in law always guarantees his concrete as "Fire proof, theft proof and guaranteed to crack. I hope this helped :-)
Dave