vent fan

Looking for advice to help guide what help I need to resolve. I have what I think is a venting problem with my home. Every few weeks my kitchen sink will backup and not drain correctly. If I run the disposal, it pushes all the water into the other side of the side-by-side kitchen sink. I...

I'm mounting a vent fan in a bathroom and made my roof penetration too close to the fan. I thought the least amount of pipe would be preferable but now see that the vent fan calls for 2 feet before the first elbow. The fan location can't be moved due to the bathroom configuration and I don't...