Vinyl Siding/ Apparent Heat Damage ?

[Robert Foster]

On first look I'd think something was wrong with the gas fireplace, which heated and deformed the siding. I pulled a few pieces of the siding off (this was not during or for an inspection) to look at the sheathing, which as you can see was undamaged. I'm perplexed as to what caused this damage and looking for some help.

This is on the north east corner of the house and never gets any direct sunlight.

Thank you

[Scott Patterson]

On first look I'd think something was wrong with the gas fireplace, which heated and deformed the siding. I pulled a few pieces of the siding off (this was not during or for an inspection) to look at the sheathing, which as you can see was undamaged. I'm perplexed as to what caused this damage and looking for some help.

This is on the north east corner of the house and never gets any direct sunlight.

Thank you

That was caused by the reflection off that window! The sun reflecting onto the siding melted it!! This is becoming more and more common with the new high E windows that are being installed in homes. They can place a sunscreen on that window and it will most likely stop it fromm happing again.

My guess is that the morning sun is catching that window at a certain time of the year and doing its deed then.

[Rick Cantrell]

Of course you know that there should be a WRB over the OSB.

I agree with what you were thinking. The damaged siding is likely caused by heat from the fireplace. The question you want to know is why there no heat damage to the OSB? The OSB does not damage as easily at the low temperatures needed to cause damage to the vinyl siding.
You may want to check if insulation is installed in that area.

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That was caused by the reflection off that window! The sun reflecting onto the siding melted it!! This is becoming more and more common with the new high E windows that are being installed in homes. They can place a sunscreen on that window and it will most likely stop it fromm happing again.

My guess is that the morning sun is catching that window at a certain time of the year and doing its deed then.

I think that is unlikely. The vinyl siding is damaged well below the area I would expect any reflection.

[Robert Foster]

That was caused by the reflection off that window! The sun reflecting onto the siding melted it!! This is becoming more and more common with the new high E windows that are being installed in homes. They can place a sunscreen on that window and it will most likely stop it fromm happing again.

My guess is that the morning sun is catching that window at a certain time of the year and doing its deed then.

I discounted that possibility given that this is the north side of the house, but the linear nature and angle of the damage definitely leads me to this explanation....

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Of course you know that there should be a WRB over the OSB.

I agree with what you were thinking. The damaged siding is likely caused by heat from the fireplace. The question you want to know is why there no heat damage to the OSB? The OSB does not damage as easily at the low temperatures needed to cause damage to the vinyl siding.
You may want to check if insulation is installed in that area.


If the heat was coming from the interior, I would think the damage would be more broad based and not so focused in a linear way....

The interior of the fireplace looks like it's hardly been used....

[Gregory Booth]

..........Scott gave you the right answer...........Greg

[Vern Heiler]

I discounted that possibility given that this is the north side of the house, but the linear nature and angle of the damage definitely leads me to this explanation....

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If the heat was coming from the interior, I would think the damage would be more broad based and not so focused in a linear way....

The interior of the fireplace looks like it's hardly been used....
I agree with Scott. I've seen it many times and the north side does not get a bye! My patio is on the north side and the sun will drive you off it mid summer.

[Rick Cantrell]

Reflected sunlight is a very common cause of damage to vinyl siding., and IF reflected sunlight IS hitting the siding in that area, that is most likely the cause. From the photo, it just does not look like much if any reflected light will hit the lower portion of the siding. So if it is not from reflected light, then what are the other possibilities?

[Vern Heiler]

Reflected sunlight is a very common cause of damage to vinyl siding., and IF reflected sunlight IS hitting the siding in that area, that is most likely the cause. From the photo, it just does not look like much if any reflected light will hit the lower portion of the siding. So if it is not from reflected light, then what are the other possibilities?
That area is about where I would expect to see the suns reflection.

[Robert Foster]

Thanks for all the replies.

So if it's the sun, what time frame might this occur in. Say there was formerly a large bush there that was trimmed back mid-summer, could the damage happen over a month or two ?

[Mark Reinmiller]

Thanks for all the replies.

So if it's the sun, what time frame might this occur in. Say there was formerly a large bush there that was trimmed back mid-summer, could the damage happen over a month or two ?

That pattern is a classic example of damage from reflected sunlight. I have seen almost identical damaged a couple of times. I think under the right conditions it could happen in one day.

[Jeff Zehnder]

That pattern is a classic example of damage from reflected sunlight. I have seen almost identical damaged a couple of times. I think under the right conditions it could happen in one day.

This is more common than you may think. It just takes the right conditions and as Scott has stated it is reflected light. All it needs is the home to have the right angle, the window glass to have the proper deflection causing a parabolic distortion and at times it is just like burning grass when you were a kid with a magnifying glass. The window appears to be the key item, the right angle and distortion create the opportunity for focused light.

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This is more common than you may think. It just takes the right conditions and as Scott has stated it is reflected light. All it needs is the home to have the right angle, the window glass to have the proper deflection causing a parabolic distortion and at times it is just like burning grass when you were a kid with a magnifying glass. The window appears to be the key item, the right angle and distortion create the opportunity for focused light.

Also we had a couple of TV news crews in this past year in the Raleigh area, just Google melted siding on the local Raleigh TV stations and it should come up!

[Robert Foster]

Wow, this is pretty amazing to me. Thank you for all the replies and the education.

Here's an episode of This Old House that shows the exact same thing. (http://www.thisoldhouse.com/toh/tv/ask-toh/video/0,,20677469,00.html)