We have a composition shingle roof and 2 years ago added an addition. There is one 8 foot section where the addition pitch meets the old roofs oppostite pitch and a valley is created, along that 8 foot section at the hottest peak of the day the upper wall roof area makes loud popping and cracking sounds. The sound is extremely loud and goes on from 4 in the afternoon till about 6pm, then again at about 2am for an hour when it cools back down. I read that this is probably thermal expansion/contraction of the trusses, however, I did not read what can be done to silence the noise. This shuttering loud noise happens daily all spring and summer exactly the same time of day-everyday (and night). We have lived here for 17 years and it started when the addition roof was built. I also read something about that the roof needs to be able to move free one end and if it is restrained from movement, that can cause the noise problems as temperature makes it expand and contract. I sure hope there is a knowledgable roofer that reads this and can give me advice on what to do to silence this ridiculously startling daily poppping/cracking sounds. Thank you in advance.

 

Does the addition have any venting? Because it sounds to me like you might be describing a hot unvented attic space. The problem might be alleviated by adding one of the following types of venting to the addition: a gable end vent, ridge vent, can vents, turbine vent, etc... to keep the temperature inside the addition roof from getting so extreme.

 

Yes it has ridge venting, and we too thought it might still be a ventilation problem so we hired a roofer and added eybrows recently to see it that would help with the sounds but that was not it. The roofer was quite knowledgable about roof vents and he opened the ridge to make sure it was done properly and added the eyebrows and he says we have plenty ventilation, but still the super loud cracks and pops.

 

I am still persuing what the answer might be to this problem. The area the loud pops come from is where the old portion of the house meets the new addition and happens only on the side where the heat hits it at the hottest time of the day and cooling time of the mid-night. It sounds more like it is coming from the wall cavity of the old wall not really the roof, but I was earlier lead to believe it might have something to do with the trusses of the roof, maybe how the old wall attaches to the new addition?????? ANY help would be great. The loud sounds are for many hours during warm and hot days, not in winter and have only been happening since the addition has been added a few years ago. I am worried that someone would not want to buy the house fearing something is wrong with it. We want to silence or fix it if there is something wrong with it.

 

Did the carpenters cut an access hole that leads from the old roof attic into your new roof attic? If not, I'd suggest you have one cut in. If nothing else, it will keep the temperature in all areas of the roof a little more constant, and would allow a person to get up in there to listen!

Truthfully, that's what I'd suggest. Take a cooler of lemonade and a fan up there and listen for the problem area. I'm guessing that it is probably the nails that penetrate the sheathing moving up and down. If so, they could be clinched by beating them over from underneath, which might help. Also, if you can get into the new addition, you could glue the rafters that land on the old existing sheathing, in case there is movement there.

It almost seems like trying something would be better than doing nothing, and maybe by the process of elimination one of the solutions you try will work.

 

The new addition has a cathedral roof, the old part of house has a regular 8 foot ceiling with attic. Read previous posts, the ventilation has been addressed and more ventilation was added, but that was not the problem. The sound is coming from the old wall that connects to the new addition, just the first 8 feet of the old wall makes the LOUD sounds during the hottest part of the day. What about an expansion joint problem in the wall?

 

adtcrazy: I have been following your discussion with XSLEEPER about your cracking roof. I knew from your first post there was more to the story. but XSleeper was trying to help you and you told him to read the past posts on ventilation. Well now I will jump in here. Your old roof is popping and crackling because of the way they were attached together. It starts where the ceiling line was converted. Who ever did the job, no doubt attached the catherdral truss to the standard truss. There should be a space between them, maybe only 1/8" or so. Just a little space. Heat now rises in the catherdral area, and also on the outside. The catherdral ceiling expands with the heat, and takes the old standard trusses with it. You hear the lifting when it is hot, and the cooling when it cools off. It is the catherdral roof which moves and drags the older roof with it. That is why you leave a space when converting from standard to catherdral. In the fall, winter and early spring there is no sound, since there is not enough heat. About the only way you will stop it for sure is separate the two sets of roofs where they are joined. This also includes the roof sheeting. This is not a good job. This is not a cheap job. Good Luck. Oh by the way, XSLEEPER is very very knowledgeable about these sorts of things. He was simply trying to cover all of the ventilation bases, before he went on to bigger and more expensive options. Again good luck

 

Thank you for explaining, this makes sense. Now, last question, since it is going to be a big expensive job to fix, do I need to fix it? Will "not" fixing it cause us problems or damage to the roof or walls/structure?

 

No, it will not really hurt anything. It will just be noisy. However, over time, maybe a year or two, the noise will subside.

 

Thank you, this thread will help many others, as I searched and searched the internet and found many others with the same problem, but no answer to the cause and effect. This forum is great, I've used it for many home construction perplexing questions.

 

Your very welcome.