Expert: Bruce E. Johnson - 2/20/2009

Question
QUESTION: Hello, I recently added an addition to my house and now find that when the wind hits the house directly, it causes a loud creaking sound in the ceiling of my bedroom (which is part of the new addition)near the exterior wall that gets the brunt of the wind.  I've been up in the attic and it's coming from underneath the plywood floor.  I can't seem to pinpoint where exactly the noise is coming from.. it seems to radiate all over the ceiling. Also  I don't see any cracking in the drywall.   I have vinyl siding on the outside of the second floor and brick on the first floor.  The noise is unbearable during wind gusts of 15 mph or more.  I'm attaching pictures of the framing that I took during construction.

ANSWER: Hi John, from this picture I don't see any attic space.  It looks to me like the roof system is stick framed and the ceilings are vaulted rafters.  I can foresee a potential problem with the way the valley framing is done.  If that valley beam isn't beefy enough I can see that valley having a tendency to flex inward. Also that gable end behind the guy bending over should have had the storm sheathing catted at the joints so that each sheet of exterior plywood has a continuous nail pattern on the edges.  Running the plywood horizontally on a gable end like this is okay but without the seams being nailed solid I can see this wall flexing inward in a strong wind.  It is also possible that if what I am looking at is the second floor and the noise is coming from below the floor decking then your floor system may not contain the proper bridging and the floor system is flexing laterally with the walls.   I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com

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QUESTION: Hi Bruce, Thankyou very much for your input and quick response.  Just to clarify, the ceiling is partially vaulted and cross beams were placed about 4 feet above that window so there is attic space up, although very small(more like crawl space).  So the NOISE comes from that area between my ceiling and the attic floor and it's concentrated in the area of that exterior wall.  I'm attaching another pic of that room so you can see the cross beams that were place to make my ceiling.  I had a contractor over today and he said that what we have to do is take off the vinyl siding off that wall and the exterior insulation foam board and re-nail all that plywood that was done on that wall.. He feel that it wasn't nailed enough... while we were up in the attic (crawl space) we saw that a lot of nails had missed those studs.  He feels that the plywood moving and causing friction with the wood is what's making that horrendous noise.  WHat do you think of his theory and solution.. Thank you again for your help.

Answer
Hi again John, you have reinforced my original supposition that the exterior plywood is nailed improperly.  Let's hope it is just the wall sheathing that needs to be renailed and not the roof sheathing as well.   Please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com