Hire a certified arborist to deal with the branch(es?) rubbing on the house.

To begin, it's important to understand what topping is and why it's so detrimental to trees. The International Society of Arboriculture's Website, www.treesaregood.com, has the following helpful explaination: Why Topping Hurts Trees

Most pruning cuts on mature trees should be done by removing entire branches. Knowing where and how to make the cut is critical to ensure that the tree can properly recover from the wound. Improper cuts encourage rot, disease, pest damage, and possibly eventual failure of the tree. Here is the ISA's presentation about basic pruning technique: Pruning Mature Trees

Occasionally, reduction cuts or drop-crotch cuts, can be beneficial, especially when directional pruning is being done. Here is some information from the University of Florida: Reduction (why) and Reduction (how)

There are lots of good pruning videos on YouTube (as well as a few that are misguided). Here are a couple or random examples of some good ones: University of Kentucky's Video on Pruning Landscape Trees (How-To) and Winston Salem's Urban Forrester on Proper Technique of Tree Pruning

Thanks for the replies - I appreciate the info! One quick word, when I wrote "topping," I meant methodically reducing the height of the tree with individual cuts - branch by branch.

I didn't know topping meant the indiscriminate lopping off the top of a tree.

Ken - the tree sheds leaves almost year round, but it is healthy & the shedding isn't excessive.

Brandon - I really appreciate the links you posted. The second link directly addressed one of my questions regarding dressings.

My magnolia is a beautiful tree and while I'd like it to be more manageable, I don't want to damage it.

"...when I wrote "topping," I meant methodically reducing the height of the tree with individual cuts - branch by branch."

Topping refers to the type of cuts, rather than how many cuts are made at once. Large heading cuts, or stub cuts, used to prune trees results in topping. Topping almost always results in permanent damage and frequently leads to the decline of the tree. Properly and completely removing entire branches and, in some cases, using reduction/drop-crotch cuts is the way to prune correctly. That last YouTube video does a pretty good job describing topping and its results.

> Posted by brandon7h
> rather than how many cuts are made at once.

That brings up a point that would be good to mention
in the interest of this tree. I have read that
no more than a third of tree's foliage should be removed
in the same pruning.
The statement no doubt also assumed no subsequent prunings until
long later (probably next growing season).