Be careful, a reputable roofer a few years ago was on roofing forums bad mouthing iko, next thing he knew he had lawyers at his door!!!We had the caimbridge IKO shingles put on and within 6 months the did not seal and started curling. We even had our contractor put zip board down to insure that the warranty would be valid. By the time I finished with this roof it cost me 20,000.00. When the rep came to look at the shingles with my contractor he said he did not see any problem with our claim. The contractor did every thing right including hand nailing the required amount of nails. That isn't what IKO claims though. They nulified our warranty saying that it was not nail properly. Now we cannot get the rep to even call us back. And IKO well all they had to say was go ahead a sue us. I cannot believe how they just don't care and they don't stabnd behind there product. I hope everyone thinks twice before buying this product because no matter what you do, you do not have a warranty as far as IKO is concerned.