Causes of vinyl siding damage: buckled, rippled, bent, deformed, loose, or un-clipped: why does some vinyl siding take on an ugly look with ripples, bends, bulges, or even loose ends?
Here we discuss all of the know causes of this defect. Watch out: rippled or loose vinyl siding may be more than just a cosmetic worry, and may indicate structural defects, building movement, leaks, or even heat or fire hazards. Our page top photo shows wrinkled vinyl siding - often caused by heat exposure but in this case the extent, location, pattern and size of the damage made us suspect that there was another cause, as we explain below..
Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.
How do we Sort Out the Causes of Rippled, Bent, Buckled Vinyl Siding: Product Defects, Sunlight, Heat, Installation Errors, other Causes?
Reader Question: what is the probable cause of the buckled, rippled, loose vinyl siding in these photos?
First of all I would like to commend you on an excellent web site. I have considered it a valuable resource in my field of investigative engineering.
[Photos courtesy J.B. Click any image to see an enlarged, detailed version]
I was recently on your website viewing your information about vinyl siding damage and defects. I had an investigation just yesterday where I saw warped or rippled siding at a north side wall. This is a non-weathered side in Tacoma, Washington.
There is about 5’ of space between the wall and the property line fence and no utilities, etc. at that wall. There is a main floor living room and an upper floor master bedroom and that is all.
I have included some pictures for you that you may want to share on your web site and possibly comment on. There was no visible physical damage and no evidence of any water intrusion. At the worst areas the vinyl siding was pulled away from the wall and there was no staining or streaking over the building paper nor was there any bubbling of the paper or damage to the OSB sheathing found.
Trapped moisture between the siding and building paper due to late fall-early spring damp weather and low temperatures is the only thing that seems reasonable at this time, except for the possibility of material defect, but I am not aware of any such defects matching the conditions seen. The residence was built in 2005. Thanks, - J.B. P.E., Auburn WA
Reply: probably defective vinyl siding product; list of other siding buckling rippling bending diagnostic questions
Without a confident diagnosis of the cause of these vinyl siding anomalies I'm reluctant to rule out anything yet, but moisture as a root cause of rippling/buckling would surprise me; I think that plastics buckle and bend more in response to heat and physical stress, or sunlight and photo oxidation than to moisture exposure.
If I had to make a guess before we know more, I'd guess a defective product, thin and poorly formulated;
We might see product defects showing up inconsistently on different building walls for several reasons: exposure differences, installation differences, even different boxes or batches of product at the jobsite.
Since it would be odd for a quantity of defective siding to precisely match the square feet of a single building side or wall, I'd expect to find either some un-damaged siding (different product) on the mostly-damaged building wall, or some damaged siding (defective product) in some areas on other walls.
According to our siding contractor Eric Galow and somewhat supported by my own field inspections, some vinyl siding may be both buckled horizontally and rippled across the vertical width of segments because of what seems to be an inferior product formulation.
Twenty or more years ago there were (and there might be today) some lots of thin, poorly-formulated vinyl siding that warped and bent when exposed to intense sunlight or other heat sources, deforming worse than some of the more special cases we have already documented in our article series at VINYL SIDING INSPECTION & REPAIR
Although you have not yet seen water damage, leaks can be a bit subtle and even hidden unless the siding is removed entirely.
So it may remain possible that this condition is more than a cosmetic defect; loose siding risks leaks into the wall structure, inviting rot, insect damage, possibly even mold contamination; and the risk of wind blow-off of siding areas is of course much increased.
Siding Damage Diagnostic Questions?
As a technical aside, and certainly not having to do with the root cause of this badly rippled, loose, buckling vinyl siding, in the photo at left (click to enlarge) I see what looks like "more clean" vertical sections of wall siding in the upper right quadrant of the picture. There may be an insulation void or other interesting building condition going on there.
It would be diagnostic in confirming that the root cause of this siding damage is defective product if we could rule out other factors; Can you tell me
Other useful diagnostics for this siding buckling, rippling, and loose ends all found in one place would include:
Thanks! My opinion is that it may likely be indirect heat reflecting from an upper floor window of their neighbor’s house which faces the damaged siding. The siding damage is between the upper floor and stops about 5’ above ground so it is at a specific location. The somewhat widespread uniform warping would seem to indicate it is not a material defect.
If I get permission to check the manufacturer I will let you know. Thanks for your input and I agree that we all learn from each other’s collective experience, etc. - J.B.
I must have missed that option in our correspondence.
There is no doubt that reflected heat from sunllight can cause rippled damaged vinyl siding - as I show at
the page top photo
Vinyl siding will buckle due to thermal expansion if it is not properly installed. Properly installed here means proper placement of siding nails, not over-nailing too tightly, and allowing proper end clearance at single-piece siding runs to allow for thermal expansion.
Experienced vinyl siding installers who want to avoid siding blow-off (see VINYL SIDING INSPECTION & REPAIR) refer to "hanging vinyl siding" on the building wall rather than "nailing vinyl siding to the building wall" precisely to remind workers not to nail siding so tightly that it buckles when heated.
On a wall section long enough to have spliced sections of vinyl wall siding in a given siding course, if we see vinyl wall siding that is buckled, we also check to see if the siding moves freely left and right on the wall.
It's easy to either use the butt of your hand to try to slide a siding panel left or right - it should move about 1/2" or so. If the siding feels tight we may check further by grasping the end or edge of a siding section to see if we can pull or push it.
When locking the vinyl siding panels into position, do not force them up or pull them down to adjust the alignment. Too tight panels can tear and too-loose panels can unlock and come loose. One exception is at the band joint between the first and second floor where panels may come unlocked due to shrinkage of the framing. To compensate for this, some contractors pull the panels a little tight over the band joist area.
Detailed specifications for hanging vinyl siding to avoid buckling and blow-offs are found in our article VINYL SIDING INSTALLATION - see:
Vinyl siding that buckles due to improper nailing (photo shown above) is is not normally extremely wrinkled, and will be more wavy across longer horizontal runs of surface. And of course, more severe buckling vinyl siding will be found on a building sides more exposed to sunlight.
As we mention also at VINYL SIDING INSTALLATION, heat damaged siding (shown in our photos below) is not a vinyl siding product defect and needs to be distinguished from siding that has buckled from heat from the sun combined with improper nailing.
Heat damaged siding looks like the examples we show in our photographs below.
Vinyl Siding Deformation Caused by Local Heat Source - Barbecue Grill
Watch out: we sometimes find badly buckled or even burned vinyl building siding where someone placed a barbecue grill too close to the exterior wall (photo above left). And on rare occasions we've found siding that was buckled as if by this problem, but in a location where we couldn't imagine a barbecue taking place (photos below ascribed to unknown conditions, possibly heat leaks).
Vinyl Siding Deformation Caused by Other Hazards: heat leaks, chemical spills, reflected sunlight & heat from nearby surfaces, or unknown
Originally we thought the product at right was defective, or that it may have been damaged by a solvent. But it is difficult to imagine that defective siding would have been cut and installed with the rippled effects in such a regular pattern.
Further Investigation of Rippled or Deformed Vinyl Siding Points to Reflected Heat vs Actual Fire Damage
Watch out: for heating equipment installers who may run a metal vent through a vinyl-clad wall such as the installation shown at left Vent materials that get hot may risk a fire, or at least risk damaging the siding. (Photo courtesy Carson Dunlop Associates.)
To understand with confidence why the siding at above right shows that rippled, bending effect, we recommended investigation
See How to Repair Loose Vinyl Siding or Remove and Reinstall Part of a Vinyl-Clad Wall for suggestions and special vinyl siding tools that are used to remove and replace vinyl siding in the middle of a wall.
The photographs above illustrate the more extreme vinyl siding damage observed as characteristic of a building fire.
At above left we illustrate a sure clue of hidden rot or insect damage: crushing buckled vinyl siding at or close to ground level. Further investigation in this New York home disclosed a wood floor built actually on and below grade level and very extensive termite damage to the building's wood sills and floor structure.
Though there was no access below the floor without demolition, this visual clue launched an appropriate investigation and avoided a costly surprise.
At above right this building in Northern Main has settled and sagged enough to actually bend and tear the vinyl siding.
Finally, in our photo at left you can see deformed vinyl siding that has pulled away from the building due to collapse of the lower roofed structure to which siding was attached by glued-on (and improper) roof-wall flashing.
The leak into this wall was a contributor to insect damage in the building and is discussed further at Loose Vinyl Siding: Blow-Offs, Fall-Offs & Nailing Defects.
Continue reading at VINYL SIDING GAPS, HOLES, CRACKS or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: are there structural issues with wrinkled vinyl siding?
No where does it tell me if there are structural issues with wrinkled siding. Mine is in a place where it doesn't matter if it's wrinkled, but I don't wish to have the structure integrity compromised. - Carol Heitlinger 6/9/2012
Quite So, Carol.
We don't expect to blame "wrinkled siding" such as the heat-damaged siding above, or buckled siding described in the article above as a structural integrity problem.
Since building siding is a skin that is "hung" on the structure, usually wrinkles in the siding are usually due to heat such as from a BBQ grille placed too close to vinyl siding, or more often wavy siding is due to improper fastening of the siding to the building (nailing too tightly) combined with the effects of heat from sun exposure - not a structural defect.
The picture with the dryer vent below the window (see Buckled, Rippled, Deformed Vinyl Siding Caused by Other Hazards: heat leaks, chemical spills, unknown above) was caused by the reflection of the sun off the window. I would put $$$ on it. - Jim Hilt 9/11/2011
There's a good chance the rippled effect on the siding was caused my improper dryer vent installation and hot dryer air is leaking behind the siding. - Anonymous 9/15/2012
Thanks for the guesses, Jim and Anonymous.
But in this case, while I thought you might have something there, after a more careful check, I don't think so. Look at that photo again carefully - you'll see that the rippled vinyl siding extends way below the opposing window - not in the path of reflected heat from the window glass.
We have expanded our discussion of the rippled vinyl siding effect to explain the difference between obvious heat damage from a barbecue grill and the odd rippling in our photo above. The vent you saw is not for a hot air dryer, it's an air intake for a fireplace insert built into that chimney chase. But your guess is a good one in that there may be a more dangerous hot gas leak from the fireplace. For that reason we recommended invasive inspection to check the chimney chase interior as well as the condition of the fireplace
For additional photographs and discussion of all types of sagged, torn, cut, broken, rippled, or otherwise damaged vinyl siding, take a look at these subtopics found in the article above:
Reader Follow up / Comment: Vinyl Siding Rippling Caused by Sunlight & Heat Reflected from Nearby Windows
The picture with the dryer vent below the window was caused by the reflection of the sun off the window. I would put $$$ on it. - Jim Hilt 9/11/2011
On the contrary! As the sun rises in the sky, the reflected light and heat move downward on the wall. That softening pattern is exactly where it should be. When the window and adjacent wall are so close together (and always facing south and west), no breeze carries the hot air away.
Between the direct sun and the reflected sun, you get high temperatures on the surface, but it's rare to see damage from it, because usually airflow cools the surface off. When you put them too close together like this (and again, oriented to the sun just-so), the pocket of dead air allows temps to get even higher and you see the damage shown. - Mike in Michigan 11/28/2012
Thanks so much, Mike! We are so grateful for your very interesting explanation of our "mystery" rippled vinyl siding. Your analysis looks very reasonable & sound to me. Though I needed to see the careful reasoning in your comment, now I'm convinced.
Indeed this side of this home faces roughly South and the side of the facing chimney chase was indeed, in some weather, a hot, dead-air space.
We will look for other examples of the case you describe and would welcome photos of this vinyl siding damage type from other readers. (Use the CONTACT US link found at page top or bottom to send us email & photos)
We appreciate your taking the time to comment: working together we are smarter than anyone. - Daniel
Questions & answers or comments about Vinyl Siding on Buildings, Installation, Inspection Methods, Defects, Diagnosis & Repair.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References