PVC is not a suitable flashing material in any building assembly. It will tear easily, dissolve when in contact with modified asphalt and certain sealants and it becomes brittle and inflexible over time. Take it all out and install Ice & Water Shield (by Grace) to seal the skylight to sheathing joint and then add metal step-flashing (usually supplied by the skylight manufacturer) interleafed with the shingle roofing and then reinstall the skylight cap to protect the top of the metal step flashing. Squirrels will have no interest in metal flashing. If your roofer doesn't know how to do this standard detail you can fire him or you can print out the Velux skylight installation instructions. The squirrels have done you a favor because the PVC flashing would have eventually failed and caused damage to your interior finishes.

Check with the manufacturer. Often the curbs can be made from 2x4's or 2x6's. Most builders/roofers make them from 2x6's because the flashing doesn't need to be trimmed on site. If it's of no consequence to the finished product, then 2x6's are more convenient. Yours look to be made from 2x6's and if you check with the manufacturer, you might be able to reduce the height 2" by redoing them with 2x4's. It's not an easy job to change them out to 2x4's after everything is in place, but if it's important to you, then it is quite doable. Those skylights are very blocky, angular, and high profile as well. Another product, like a Velux skylight, has a much lower profile and sits lower on the curb (worthy's photo in a post above) and that might be another option for you to consider. (If you change over to Velux, you'll also have to change flashing to retain the manufacturer's installation warranty, but with a 2x4 curb and the lower profile skylight, I'm guessing you'll be able to reduce the height above the roof by approximately 3".) If you're intending to replace the make of the skylight or the type of skylight with deck mount, make sure the inside curb/rough opening dimensions are the same or you might be adding significantly to the cost in unexpected ways with framing changes. In terms of positioning: I might be mis-interpreting the photo, but unless there are other considerations with obstructions, etc., usually the best location for skylights is in a position favoring the center or dark part of the room to complement the light from the windows. It's what skylights do best: bringing light into the center of the room. Hindsight is 20:20 right? Having three positioned near your windows won't do a lot for you in comparison to the two that you say are already positioned back further in the room. Without seeing the overall design, I suspect my choice likely would have favored just two larger skylights back towards the center/rear of the room negating the need for three 2x2 skylights at the windows. If you do refit the skylights, it might be worth considering repositioning some or all of them back up the roof a ways to bring light into the center of the room. Yes, and the installers didn't take their time with the flashing. Just got sloppy. If they are re-doing the curbs, they may have to re-order some flashing and make sure they take their time with the next install to get the flashing seated tight and trim as necessary so that it doesn't protrude above the curbs and get flexed by the skylight and/or the mounting screws when it is in position. If you choose to retain these skylights, then fixing the flashing issue shouldn't take them long at all and you should expect it. Personally, all else being equal, I prefer to recommend curb mount skylights. They take longer and are more involved to install and drywall on the inside. But the trade-off is that at some stage, homeowners are going to need a new roof. In my experience, the majority of roofers are far more comfortable reinstalling a roof around an existing curb mount skylight as opposed to a deck mount skylight. There's less room for them to screw up and they usually have the materials on hand to make flashing repairs/replacements. Deck mount skylights require that someone on the roofing team reads and becomes familiar with the installation instructions and the chances of that occurring are somewhere between slim and none, and the materials necessary for repair are not necessarily in the roofers' on-site toolkit. Roofing crews that know what they are doing around skylights are worth their weight in gold.

Hi all, I am hoping this thread is still active and monitored because I could really use some expert help. I had my roofer replace my roof including a 20-year old plastic skylight with the Velux fixed curb mount skylight (see photo below of the old skylight): The problem is that we live close to a highway and we can now hear the outside noise A LOT more than before even though the roofer said the new Velux skylight has the noise reduction feature. The roofer consulted a Velux rep and the rep told him that if he chose a deck mount, it would have reduced the amount of outside noise. The problem is that Velux apparently does not make the fixed deck mount skylights in size 45 1/8 x 45 1/8, but Wasco does. The other option was to do an "additional insulation job" on the already installed Velux curb mount skylight hoping it would dampen the outside noise. I have no idea what that means since I am no roofing expert. (see photo below for the NEW curb mount skylight) Here are my questions, please: What could be the reason why we now hear more noise than before? Would changing from a curb mount to a deck mount reduce the outside noise? Are Wasco skylights just as good with noise reduction as Velux? How would you best solve the problem of the outside noise (without eliminating the skylights :)? Thanks for any advice and recommendations you can provide!

Thank you above all. 1, yes, this brown dome skylight is no cost, it was wrapped well in my attic from previous owner, I just teared off wraps. My understanding is the current cracked one has been there at least 15y, For me, it is acceptable if it could make another 15y after replace it. 2, I can go to glass one under reasonable cost ( is glass easily to crack?), but don't know where to order, if the new glass one need totally redoing the frame, it could increase the cost a lot, I hope I could get it done under $500. 3, I don't know any pro around and where to find one, Those guys who replaced my roof said: since the underneath iron frame was nailed in, they could not simply replace it. But, after I checked the structure in and out ( Please see the diagram I drew), it looks to me, I could replace it without touching the iron base frame, so not touching outside flash either, I could only unscrew the outside "retainer frame" then put back with new skylight.