Saibal Sen
Complete Roof newbie
2/8/2011
Hi, I began this quest to replace the roof our 47 year California ranch style house (3000 sqft roof). The shakes have curled up quite a bit, and every roofer passing by knocks on our doors offering their service. It hasn't leaked as yet though the roof chatters in 30-40 mph winds. However, the reason for replacement was not the age or the looks. It was the roof rats! They get in and conduct relay race on some of the nights which is sending our obese cat into severe depression. We started with the idea of the cheap composite roofing, but now are sold on Metal roofing. We have new attic insulation (I think R29/R30) - put in about 5 years back. The roofer who is recommending Gerard Classic Tiles is suggesting installing the metal tiles over the existing roof and somehow I am not fully convinced as yet (maybe my ignorance). I have trawled this forum and other sites to do my studies, but appreciate a response to my specific situation. 1. Ours is a "termite" country and we have had Orange oil termite treatment done for dry rots on few spots in the roof frame a year back. By not removing the roof, am I running a big risk of not detecting issues that the termite treatment folks missed? 2. In the roofer's proposal, he specified 72 lb CAP sheet - is that the underlayment? 3. The roof has some sag in one place over the garage and he felt that it will be easy to smoothen out using shims under the wooden slats he will install to mount the metal tiles. Is that advisable? 4. He said that additional weight of about 1.5 lb per sqft of new metal roof is still less than the "wet weight" of the cedar shakes and so structurally we are fine. 5. We also live in the "earthquake country". Will there be any issue is the wood shakes are not removed? 6. He is proposing TWO eyebrow vents to cover all the venting needs based on about 12 soffit vents. No attic fans. Our summer temp is usually a max of 95F and in winter we go down to 35F min with only 3-4 days of 100F days and 32F winter nights. Sorry for the very long post, but appreciate any advice.
Info @windowsonwashington.net
An informed customer is our best customer.
2/8/2011
1. Potentially. If the structure is sound, that is a good indication that you are okay but visually inspecting it would be best. 2. No. Cap sheet is used most times in low slope roof applications. 3. You can correct sag with shimming as long as the sag is not a structural defect. 4. That depends largely on how much water the shakes take on but you are probably safe with a lightweight steel roof in this case. 5. Not as long as battens/purlins are properly fastened. 6. The over deck venting will help lessen the requirement for venting in this case from the standpoint of controlling heat. The necessity for ventilation as it pertains to moisture depends entirely on the home.
Saibal Sen
Complete Roof newbie
2/9/2011
Thanks a lot for the detailed and quick reply. I think I will abandon the plan for over the existing roof installation.
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