Expert: John Henry Architect - 5/25/2008

Question
QUESTION: Hi, I am buying a house with hairline cracking on the ceiling in the den, hallway near the vent and master bedroom. They are about 16inches long. The ceiling surface is flat, is not high ceiling. Are they something I should concern about? Please advise. Thank you.

ANSWER: Reason of cracking depends on several things:

Age of house
Humidity change
How new is the crack?  What is the exact width? Did it form over time?
What is the framing or structural system?
Are there any cracks in the outside wall close to the ceiling crack?
Is the foundation stable?
Is the crack in a drywall or hand applied plaster ceiling?

Normally in an old house these cracks indicate settling of the foundation, and the plaster was hand applied.

In a newer house the reason can be the same: foundation settling.  But this means that the foundation is cracking if concrete or moving if on piers.

Nearly new homes or ones just finished with sheetrock over wood frame are susceptible to cracking in many places when the humidity and temperature change dramatically.  And it will happen in several places.  Not necessarily a foundation problem and can be simply refinished.

A structural engineer should be called in if you suspect foundation settling.  Cracks form in this case due to stresses resulting from either soils expansion or retraction, unstable fill, or errors in structural design and installation.



---------- FOLLOW-UP ----------

QUESTION: Mr. Henry:  Thank you for your answer. I like this house was build in 1989 on a raised foundation on a hillside. The front portion of the house is on the flat land. The rear portion, deck is set on the hill. There are 2rooms in the basement. I will ask the seller the question you mentioned on the answer sheet, and possibly stop to take a look of the house again. Do you refer any structural engineer to me. I am in Pasadena, California. Thanks.

Answer
This type of hillside location can cause shifts in foundation resulting in the hairline cracks.  Look closely at these cracks and at nearby walls to see if there has been any paint or reworking of the finish. It could mean that settling and movement of the house has occurred over time.  Whether or not this problem is slight or serious can only be answered by an engineer or building inspector.  If you are in a seismic zone that could also be the cause. If you have a mortgage company that can refer the insurance agency, that office would have a building inspector.
My offices are not in your area so I cannot recommend anyone specifically.
Thank you,
JH