# CD's, how durable are they?



## Michael56 (Sep 12, 2007)

I need to store some copied CD's somewhere away from the house in case of fire or other problem that destroys the ones at the house. I have a storage unit that isn't heated but it's inside a building. The building is unheated. I'm not sure how cold it gets but it does get pretty cold. Would the CD's be okay over there? Would the data be okay? If I let them reach room temperature before using them would that work?


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## Cyps (Jan 3, 2006)

As long as the temperature stays above freezing and they remain dry they should take no harm. I store mine in an unheated area and had no negative effects yet. I would think too much heat would be worse for disks than cold. Just make sure you are using quality disks in the first place. Poor quality disks will deteriorate over time anyway regardless of temperature.


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## Michael56 (Sep 12, 2007)

I really doubt that it freezes in there but I can't be sure. I guess I could take a container of water over and see if it freezes. I agree that heat would be worse than the cold. It was late October when I rented the place so I'm not familiar with how hot it gets in there. Thanks!


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## SB305 (Sep 20, 2007)

About the worst place in which you can store plastics in a house is the loft, the reason being the wide and frequent variations in temperatures there. I've seen discolouration, brittleness and even cracking occur within a few years in thin ABS mouldings left in my loft.
If the storage unit you have obtained undergoes similar cyclical variations in temperature, it would not be a good choice of location to store important backups on CD.
CD's are vulnerable also to degradation from high humidity.
This is not a commonly shared opinion in these forums, but I personally would not entrust important records solely to PC-burned CD-R's for any longer than 2 years anyway - simply because I've seen several, originally good, PC-burned CD-R's and DVD-R's fail irrecoverably during that period.


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## Michael56 (Sep 12, 2007)

So I should make new backups every two years or so?


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## SB305 (Sep 20, 2007)

As I said, you won't find many posters agreeing with me on this, but I'd never rely on a PC-burned disk as a sole backup in any case.
A hard drive is likely to be more reliable, with an average predicted life of 5 years, but that's just an average guesstimate - an individual drive could fail at any time.
I store a lot of my backups on flashdisk AS WELL AS hard disks and PC-burned disks. Murphy's Law is alive and well and living in PC Media. 
In any event, if the data you're storing is sufficiently important you will need to check the backups at regular intervals.


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## Michael56 (Sep 12, 2007)

I also use flash drives. But I will make sure that I check the data on a regular basis. As you say, Murphy's Law is alive and well! Thanks!


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## Cyps (Jan 3, 2006)

Another detrimental factor is high light levels. The average building shouldn't pose much of a threat and won't concern anyone who stores disks in cupboards etc, but any disks kept in transparent wallets or disk cases shouldn't be exposed too much. I don't want to add any more angst, but the more you are aware of the better, for example you may be tempted to place some on a window shelf having run out of storage space. Just don't!


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## Michael56 (Sep 12, 2007)

Yeah, I already assumed that light would, or could damage them. I keep them enclosed in a box. Thanks!


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## Elvandil (Aug 1, 2003)

Freezing temperatures should have absolutely no affect at all on CD's. They contain no water. The only thing cold temps will do is make them brittle until they warm up. Cold, in fact, will probably extend their useful life.

Temperature variations, however, are not good for anything. The constant changes of temperature, especially if rapid, can cause tiny thermal cracks that will eventually destroy the integrity of the CD's.

A constant temperature, if possible, is the best storage solution.


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## Cyps (Jan 3, 2006)

Elvandil, I'm not sure I understand when you say freezing does no harm yet you say it makes disks brittle. Isn't that just to be avoided as is too much heat? I fully agree when you say keep at a constant temperature, but not always easy if a building is unheated as is the case here. I reckon if they are kept in wooden boxes or cupboards there's no need to worry.


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## Elvandil (Aug 1, 2003)

Everything becomes more brittle with lowering temperatures and then becomes less brittle when warmed. That is not necessarily a bad thing, though going back and forth can have bad effects sooner or later. I'm not saying that they *stay* brittle.

But in the absence of water, there is nothing special about 32 degrees. You'd do far more damage to them if you picked tham up from storage when the temp was -40 and then brought them home to a warm room than you would by leaving them there at -40 and waiting until they gradually warmed before bringing them home. It's not really the actual temp that will matter (unless hot), but the temp changes that are most likely to damage them. And the more abrupt the change, the more damage.


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## calvin-c (May 17, 2006)

Storing them in insulated envelopes might help. Not that it'll keep them from getting cold, but if you transport them in the envelope then it'll slow the temp change. (And since the insulation also makes the envelopes padded transporting them in the envelopes isn't a bad idea either.)


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## Elvandil (Aug 1, 2003)

calvin-c said:


> Storing them in insulated envelopes might help. Not that it'll keep them from getting cold, but if you transport them in the envelope then it'll slow the temp change. (And since the insulation also makes the envelopes padded transporting them in the envelopes isn't a bad idea either.)


Good idea. Even thick paper is better than nothing. That will make temp changes gradual, cut out light, and even stabilize the humidity level.

But again it can matter what you wrap them in. Cheap paper can have residual acid (that makes old books crumble faster than books made with higher quality paper).


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## Michael56 (Sep 12, 2007)

You all bring up some very interesting points. The way I was looking at it, I figured that the cold might make them a little brittle. If I was to go and try to use one like that it could break. So, I figured that if I let them warm up to room temperature slowly they would be okay.


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## Elvandil (Aug 1, 2003)

Michael56 said:


> You all bring up some very interesting points. The way I was looking at it, I figured that the cold might make them a little brittle. If I was to go and try to use one like that it could break. So, I figured that if I let them warm up to room temperature slowly they would be okay.


Yep. And *calvin-c's* idea of an insulated envelope would just make that process more gradual.


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## Michael56 (Sep 12, 2007)

I have a small insulated bag that I used to use when I took my lunch with me to work. I'll bet that would work wouldn't it.?


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## Elvandil (Aug 1, 2003)

Sounds like a good idea. If it's safe for food, it's safe for CD's .


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## Michael56 (Sep 12, 2007)

Now, if I can just remember where I put it! :


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## Elvandil (Aug 1, 2003)

Even with all that has been said, since these are irreplaceable items, you should still have another backup, in a different format like a hard drive, so that there will be no doubt.


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## Michael56 (Sep 12, 2007)

Aside from the CD's and my hard drive I also have it backed up on thumb drives.


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## Gomar (Dec 9, 2007)

Michael56 said:


> I need to store some copied CD's somewhere away from the house in case of fire or other problem that destroys the ones at the house.


and how do you know that other place wont burn down? or be sold and the new owner wants to get rid of all the stored stuff? orit wont get robbed? I make several copies on CDs or DVDs of family photos and hand them out to relatives. If I have important work or personal files, I encrypt them, save as exe(SFX), and copy to the discs.


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## Michael56 (Sep 12, 2007)

I don't. But you can't go around "what ifing" all the time. It would be highly unlikely for the place to get burglarized or burn down at the same time as the house. If something happens at either place I'll have a back-up at the other.


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## calvin-c (May 17, 2006)

Usually you're right, Michael. On the other hand my brother had some of my stuff stored at his house up until last year, when I moved it into a storage area about 5 miles away so he could clean the place up & sell it. You'd think storing it 5 miles away would be safe, right? Last month the area suffered a major flood. Like 10' deep over 20 miles of the freeway. Fortunately both my brother's place & the storage center came out OK, but I'm now undecided about how far off-site backup storage should be. 5 miles seemed reasonable-until the flood. 100 miles isn't really practical, but I'm starting to think that that's what it'd take to keep my backup safe.


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## Michael56 (Sep 12, 2007)

You bring up a valid point. I guess you just never know. All you can do is try to do the best thing you can think of. If we had a tornado come through the area it could feasibly take out both the house and the storage. Maybe I'll make more copies and bury them in the backyard in a water proof, insulated box.  Seriously, I do have a very trustworthy friend who would store them for me. They're about 10 miles away, close enough to get to at a moments notice but far enough away that maybe it would lower the odds a bit. Maybe I'll do that.


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## SB305 (Sep 20, 2007)

How much does it cost to rent or lodge a safe deposit box at your bank and how much insurance would that carry? Maybe you have other items which also would benefit from such lodgement.


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## Michael56 (Sep 12, 2007)

I thought about that. I do have other things that could go in there. The last time I checked, the smallest box I could get was $50 I think. And I wasn't sure that I could get my stuff in there. Of course, the bigger you go the more it costs. I just didn't want to spend the extra money. And I know there are restrictions as to when you have access to it and all that. I guess maybe I'm just cheap.


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## SB305 (Sep 20, 2007)

But just figure how many terabytes of flashdisks you could squeeze in. 
A probable advantage is that the bank MIGHT deem it prudent to keep the storage area at reasonably constant temperature and humidity levels (unless it makes you sign a disclaimer clause as long as your arm  ).
Nevertheless, I would not put PC-burned disks inside a sealed food cool-bag with any amount of air still inside it; and I would drop a silica gel sachet into whatever container they did end up in - to combat condensation.


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## Michael56 (Sep 12, 2007)

Good points! :up: I didn't think about that. I agree about the food bags. I would only use one to transport the CD's from the storage unit to the house where they could warm up slowly. That's only if I decide to put them over there. The silica packets are also a good idea. I have a bunch of those somewhere.


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