SIPS Roof Movement/noise
user-980027
| Posted in Green Products and Materials on
I recently installed a SIPS roof system with a 30′ span with purlins. The owners have moved in. They are complaining about the panels making “pops” particularly in the morning when the temperatures rise. Has anyone else experienced this? Any solutions?
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Replies
Brain,
What type of roofing has been installed? Is it metal roofing, by any chance?
If the house has metal roofing, it's probably the roofing panels that are popping, not the SIPs.
The metal roof on my shop/office does that when the sun hits it. It's audible from downstairs and can be disconcerting.
Its not a metal roof, it asphalt shakes.
Brain,
What are asphalt shakes? Are they the same as 3-tab asphalt shingles? Or are they a new product designed to look like cedar shakes?
Yes, Composition roof. 3 Tab shingles, just thicker to look like shakes vs shingles
Hmmm... the noise is probably not coming from the roofing ... so maybe it is the SIPs.
Any GBA readers heard of this before?
Brain,
I have never heard of this issue...
I am just curious
You say 30 ft span with purlins
how big are the panels?
What is the purlin spacing and how thick are the SIPS?
I have owned two houses with foam over T+G and they both creak and groan with wind and temperature. The last house had quite a variety of noises. I have assumed it was the monolithic nature of the roof that both amplified the noise that is there and caused some through differential expansion and 'flying' in the wind
SIPs make for a quiet house except for when something actually impacts on the exterior surface. Then the sound is transmitted easily through the rigid foam wall.
Therefore, otherwise "normal" noises due to thermal expansion and contraction are heard more readily in a SIP home.
Here's a discussion thread with several testimonials: http://gbt.buildcentral.com/Forums/tabid/53/afv/topic/aff/5/aft/76957/afpg/1/Default.aspx
About 8 years ago, some folks were theorizing that the entire SIP would "oil can" violently with a non-vented metal roof. The thought was that the metal roof touching the exterior skin of the SIP would cause it to expand relative to the interior skin. This was never proven, but it sounded plausible to a few homeowners because that's how loud it was.
Personally, I've built two SIP roof homes, with vented metal roofing, and we don't ever hear a thing. The exterior skin must not heat up enough to cause any expansion noise.
I have a SIP house (OSB skins) with an unvented metal roof (2.5 years old). It can be incredibly loud....think Nolan Ryan throwing a baseball against the roof. It's annoying enough that I'm considering pulling up the metal roof so I can add furring strips and ventilation between the SIP and the metal.
As others have stated elsewhere, the problem seems to be most acute during mild, partly cloudy days. On these days, I can literally watch the sun go behind the clouds and tick off the seconds before the roof pops. Now that it's warmer here in Virginia, the popping frequency is less.
There are plenty of reasons not to build with SIPS (I wouldn't do it again)...the roof pops just add to the list, in my opinion.
May 25, 2011
Re: “Popping” Sounds from Structural Insulated Panel (SIP) structures
To Whom It May Concern:
R-Control SIPs (structural insulated panels) are used as load bearing wall, floor, and roof components in residential and commercial construction. The International Code Council Evaluation Service (ICC-ES) completed an extensive evaluation of R-Control SIPs and issued evaluation report ESR-2233 to demonstrate compliance to the International Building Code (IBC) and International Residential Code (IRC).
On occasion, building owners have reported distinct short burst of sound coming from their structures which include SIPs as a component. This sound has been described as a popping sound. This popping sound has been most often reported in the spring or fall when temperature changes occur rapidly from sunrise to early morning or from evening through sunset. These sounds have also been reported with intermittent changes in sun and cloud cover during peak daylight exposure.
All materials have a coefficient of thermal expansion that determines the relative amount that a given material’s dimensions will change with an associated temperature change.
The coefficient of thermal expansion is different for different materials such as wood, concrete, and steel.
As temperature changes occur, each material in the structure changes dimensions in proportion to the temperature change and the materials coefficient of thermal expansion.
As discussed, different materials have different coefficients of thermal expansion so therefore different materials will expand (or contract) at different rates. However, due to friction and other connections in structures, the materials are not free to expand (or contract).
The source of the noise is likely the restraint of construction materials when the materials are undergoing expansion or contraction associated with changes in temperature. The source of the restraint is likely friction between structural components. The sound that is heard is likely the release of the restraint within the building envelope when the expansion (or contraction) overcomes the frictional forces that are resisting the movement.
Reports from the SIP industry suggest that the noise will diminish over time. Most importantly, we are aware of no projects reporting this type of noise to be linked with a structural deficiency. We hope you find this information useful.
Respectively submitted,
Todd Bergstrom, Ph.D.
VP Technology
This is the letter I recieved from the SIPS manufacture/ distributor. It looks like there is no soultion or issues with the installation.